refactor(web): extract asset grid layout logic into AssetLayout component

- Extracts the asset grid rendering logic from `MonthSegment` into a dedicated `AssetLayout` component - Simplifies `MonthSegment` by delegating layout responsibilities while maintaining all existing functionality - Renames `customLayout` prop to `customThumbnailLayout` for clarity across Timeline components ## Changes - Created new `AssetLayout.svelte` component that handles: - Asset grid rendering with proper positioning - Animation transitions - Filtering of intersecting viewer assets - Updated `MonthSegment.svelte` to use `AssetLayout` via composition pattern - Renamed `customLayout` to `customThumbnailLayout` in Timeline and related components - Moved thumbnail click and selection logic to Timeline parent component using snippets
refactor(web): consolidate asset operations in PhotostreamManager base class
2025-12-07 01:10:00 +03:00 · 2025-09-30 00:08:14 +00:00 · 2025-09-30 00:00:50 +00:00 · 2025-09-29 01:26:59 +00:00 · 2025-09-28 19:41:41 +00:00 · 2025-09-28 19:41:41 +00:00
31 changed files with 1725 additions and 1370 deletions
--- a/server/src/services/notification.service.ts
+++ b/server/src/services/notification.service.ts
@@ -161,7 +161,24 @@ export class NotificationService extends BaseService {

    const [asset] = await this.assetRepository.getByIdsWithAllRelationsButStacks([assetId]);
    if (asset) {
-      this.eventRepository.clientSend('on_asset_update', userId, mapAsset(asset));
+      // need to specify authDto to this mapAsset request, because it tries to prevent
+      // leaking information PR#7580 which expects a userId in the auth options object
+      this.eventRepository.clientSend(
+        'on_asset_update',
+        userId,
+        mapAsset(asset, {
+          auth: {
+            user: {
+              id: userId,
+              isAdmin: false,
+              name: '',
+              email: '',
+              quotaUsageInBytes: 0,
+              quotaSizeInBytes: null,
+            },
+          },
+        }),
+      );
    }
  }

--- a/web/src/lib/components/timeline/AssetLayout.svelte
+++ b/web/src/lib/components/timeline/AssetLayout.svelte
@@ -0,0 +1,68 @@
+<script lang="ts">
+  import { uploadAssetsStore } from '$lib/stores/upload';
+
+  import { flip } from 'svelte/animate';
+  import { scale } from 'svelte/transition';
+
+  import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
+  import type { ViewerAsset } from '$lib/managers/timeline-manager/viewer-asset.svelte';
+  import type { CommonPosition } from '$lib/utils/layout-utils';
+  import type { Snippet } from 'svelte';
+
+  let { isUploading } = uploadAssetsStore;
+
+  interface Props {
+    viewerAssets: ViewerAsset[];
+    width: number;
+    height: number;
+    photostreamManager: PhotostreamManager;
+    thumbnail: Snippet<
+      [
+        {
+          asset: TimelineAsset;
+          position: CommonPosition;
+        },
+      ]
+    >;
+    customThumbnailLayout?: Snippet<[asset: TimelineAsset]>;
+  }
+
+  let { viewerAssets, width, height, photostreamManager, thumbnail, customThumbnailLayout }: Props = $props();
+
+  const transitionDuration = $derived.by(() => (photostreamManager.suspendTransitions && !$isUploading ? 0 : 150));
+  const scaleDuration = $derived(transitionDuration === 0 ? 0 : transitionDuration + 100);
+
+  function filterIntersecting<R extends { intersecting: boolean }>(intersectables: R[]) {
+    return intersectables.filter((intersectable) => intersectable.intersecting);
+  }
+</script>
+
+<!-- Image grid -->
+<div data-image-grid class="relative overflow-clip" style:height={height + 'px'} style:width={width + 'px'}>
+  {#each filterIntersecting(viewerAssets) as viewerAsset (viewerAsset.id)}
+    {@const position = viewerAsset.position!}
+    {@const asset = viewerAsset.asset!}
+
+    <!-- note: don't remove data-asset-id - its used by web e2e tests -->
+    <div
+      data-asset-id={asset.id}
+      class="absolute"
+      style:top={position.top + 'px'}
+      style:left={position.left + 'px'}
+      style:width={position.width + 'px'}
+      style:height={position.height + 'px'}
+      out:scale|global={{ start: 0.1, duration: scaleDuration }}
+      animate:flip={{ duration: transitionDuration }}
+    >
+      {@render thumbnail({ asset, position })}
+      {@render customThumbnailLayout?.(asset)}
+    </div>
+  {/each}
+</div>
+
+<style>
+  [data-image-grid] {
+    user-select: none;
+  }
+</style>
--- a/web/src/lib/components/timeline/MonthSegment.svelte
+++ b/web/src/lib/components/timeline/MonthSegment.svelte
@@ -0,0 +1,109 @@
+<script lang="ts">
+  import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
+  import type { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
+  import { assetsSnapshot } from '$lib/managers/timeline-manager/utils.svelte';
+  import { uploadAssetsStore } from '$lib/stores/upload';
+  import { Icon } from '@immich/ui';
+  import { mdiCheckCircle, mdiCircleOutline } from '@mdi/js';
+
+  import AssetLayout from '$lib/components/timeline/AssetLayout.svelte';
+  import { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
+  import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
+  import type { CommonPosition } from '$lib/utils/layout-utils';
+  import type { Snippet } from 'svelte';
+  let { isUploading } = uploadAssetsStore;
+  interface Props {
+    thumbnail: Snippet<[{ asset: TimelineAsset; position: CommonPosition; dayGroup: DayGroup; groupIndex: number }]>;
+    customThumbnailLayout?: Snippet<[TimelineAsset]>;
+    singleSelect: boolean;
+    assetInteraction: AssetInteraction;
+    monthGroup: MonthGroup;
+    timelineManager: TimelineManager;
+    onDayGroupSelect: (daygroup: DayGroup, assets: TimelineAsset[]) => void;
+  }
+  let {
+    thumbnail: thumbnailWithGroup,
+    customThumbnailLayout,
+    singleSelect,
+    assetInteraction,
+    monthGroup,
+    timelineManager,
+    onDayGroupSelect,
+  }: Props = $props();
+  let isMouseOverGroup = $state(false);
+  let hoveredDayGroup = $state();
+  const transitionDuration = $derived.by(() =>
+    monthGroup.timelineManager.suspendTransitions && !$isUploading ? 0 : 150,
+  );
+  function filterIntersecting<R extends { intersecting: boolean }>(intersectables: R[]) {
+    return intersectables.filter((intersectable) => intersectable.intersecting);
+  }
+</script>
+
+{#each filterIntersecting(monthGroup.dayGroups) as dayGroup, groupIndex (dayGroup.day)}
+  {@const absoluteWidth = dayGroup.left}
+  {@const isDayGroupSelected = assetInteraction.selectedGroup.has(dayGroup.groupTitle)}
+  <!-- svelte-ignore a11y_no_static_element_interactions -->
+  <section
+    class={[
+      { 'transition-all': !monthGroup.timelineManager.suspendTransitions },
+      !monthGroup.timelineManager.suspendTransitions && `delay-${transitionDuration}`,
+    ]}
+    data-group
+    style:position="absolute"
+    style:transform={`translate3d(${absoluteWidth}px,${dayGroup.top}px,0)`}
+    onmouseenter={() => {
+      isMouseOverGroup = true;
+      hoveredDayGroup = dayGroup.groupTitle;
+    }}
+    onmouseleave={() => {
+      isMouseOverGroup = false;
+      hoveredDayGroup = null;
+    }}
+  >
+    <!-- Date group title -->
+    <div
+      class="flex pt-7 pb-5 max-md:pt-5 max-md:pb-3 h-6 place-items-center text-xs font-medium text-immich-fg dark:text-immich-dark-fg md:text-sm"
+      style:width={dayGroup.width + 'px'}
+    >
+      {#if !singleSelect}
+        <div
+          class="hover:cursor-pointer transition-all duration-200 ease-out overflow-hidden w-0"
+          class:w-8={(hoveredDayGroup === dayGroup.groupTitle && isMouseOverGroup) ||
+            assetInteraction.selectedGroup.has(dayGroup.groupTitle)}
+          onclick={() => onDayGroupSelect(dayGroup, assetsSnapshot(dayGroup.getAssets()))}
+          onkeydown={() => onDayGroupSelect(dayGroup, assetsSnapshot(dayGroup.getAssets()))}
+        >
+          {#if isDayGroupSelected}
+            <Icon icon={mdiCheckCircle} size="24" class="text-primary" />
+          {:else}
+            <Icon icon={mdiCircleOutline} size="24" color="#757575" />
+          {/if}
+        </div>
+      {/if}
+
+      <span class="w-full truncate first-letter:capitalize" title={dayGroup.groupTitleFull}>
+        {dayGroup.groupTitle}
+      </span>
+    </div>
+
+    <AssetLayout
+      photostreamManager={timelineManager}
+      viewerAssets={dayGroup.viewerAssets}
+      height={dayGroup.height}
+      width={dayGroup.width}
+      {customThumbnailLayout}
+    >
+      {#snippet thumbnail({ asset, position })}
+        {@render thumbnailWithGroup({ asset, position, dayGroup, groupIndex })}
+      {/snippet}
+    </AssetLayout>
+  </section>
+{/each}
+
+<style>
+  section {
+    contain: layout paint style;
+  }
+</style>
--- a/web/src/lib/components/timeline/Scrubber.svelte
+++ b/web/src/lib/components/timeline/Scrubber.svelte
@@ -3,7 +3,7 @@
  import type { ScrubberMonth } from '$lib/managers/timeline-manager/types';
  import { mobileDevice } from '$lib/stores/mobile-device.svelte';
  import { getTabbable } from '$lib/utils/focus-util';
-  import { type ScrubberListener } from '$lib/utils/timeline-util';
+  import { type ScrubberListener, type TimelineYearMonth } from '$lib/utils/timeline-util';
  import { Icon } from '@immich/ui';
  import { mdiPlay } from '@mdi/js';
  import { clamp } from 'lodash-es';
@@ -11,18 +11,31 @@
  import { fade, fly } from 'svelte/transition';

  interface Props {
+    /** Offset from the top of the timeline (e.g., for headers) */
    timelineTopOffset?: number;
+    /** Offset from the bottom of the timeline (e.g., for footers) */
    timelineBottomOffset?: number;
+    /** Total height of the scrubber component */
    height?: number;
+    /** Timeline manager instance that controls the timeline state */
    timelineManager: TimelineManager;
-    scrubOverallPercent?: number;
-    scrubberMonthPercent?: number;
-    scrubberMonth?: { year: number; month: number };
-    leadout?: boolean;
+    /** Overall scroll percentage through the entire timeline (0-1), used when no specific month is targeted */
+    timelineScrollPercent?: number;
+    /** The percentage of scroll through the month that is currently intersecting the top boundary of the viewport */
+    viewportTopMonthScrollPercent?: number;
+    /** The year/month of the timeline month at the top of the viewport */
+    viewportTopMonth?: TimelineYearMonth;
+    /** Indicates whether the viewport is currently in the lead-out section (after all months) */
+    isInLeadOutSection?: boolean;
+    /** Width of the scrubber component in pixels (bindable for parent component margin adjustments) */
    scrubberWidth?: number;
+    /** Callback fired when user interacts with the scrubber to navigate */
    onScrub?: ScrubberListener;
+    /** Callback fired when keyboard events occur on the scrubber */
    onScrubKeyDown?: (event: KeyboardEvent, element: HTMLElement) => void;
+    /** Callback fired when scrubbing starts */
    startScrub?: ScrubberListener;
+    /** Callback fired when scrubbing stops */
    stopScrub?: ScrubberListener;
  }

@@ -31,10 +44,10 @@
    timelineBottomOffset = 0,
    height = 0,
    timelineManager,
-    scrubOverallPercent = 0,
-    scrubberMonthPercent = 0,
-    scrubberMonth = undefined,
-    leadout = false,
+    timelineScrollPercent = 0,
+    viewportTopMonthScrollPercent = 0,
+    viewportTopMonth = undefined,
+    isInLeadOutSection = false,
    onScrub = undefined,
    onScrubKeyDown = undefined,
    startScrub = undefined,
@@ -100,7 +113,7 @@
        offset += scrubberMonthPercent * relativeBottomOffset;
      }
      return offset;
-    } else if (leadout) {
+    } else if (isInLeadOutSection) {
      let offset = relativeTopOffset;
      for (const segment of segments) {
        offset += segment.height;
@@ -111,7 +124,9 @@
      return scrubOverallPercent * (height - (PADDING_TOP + PADDING_BOTTOM));
    }
  };
-  let scrollY = $derived(toScrollFromMonthGroupPercentage(scrubberMonth, scrubberMonthPercent, scrubOverallPercent));
+  let scrollY = $derived(
+    toScrollFromMonthGroupPercentage(viewportTopMonth, viewportTopMonthScrollPercent, timelineScrollPercent),
+  );
  let timelineFullHeight = $derived(timelineManager.scrubberTimelineHeight + timelineTopOffset + timelineBottomOffset);
  let relativeTopOffset = $derived(toScrollY(timelineTopOffset / timelineFullHeight));
  let relativeBottomOffset = $derived(toScrollY(timelineBottomOffset / timelineFullHeight));
@@ -295,12 +310,24 @@

    const scrollPercent = toTimelineY(hoverY);
    if (wasDragging === false && isDragging) {
-      void startScrub?.(segmentDate!, scrollPercent, monthGroupPercentY);
-      void onScrub?.(segmentDate!, scrollPercent, monthGroupPercentY);
+      void startScrub?.({
+        scrubberMonth: segmentDate!,
+        overallScrollPercent: scrollPercent,
+        scrubberMonthScrollPercent: monthGroupPercentY,
+      });
+      void onScrub?.({
+        scrubberMonth: segmentDate!,
+        overallScrollPercent: scrollPercent,
+        scrubberMonthScrollPercent: monthGroupPercentY,
+      });
    }

    if (wasDragging && !isDragging) {
-      void stopScrub?.(segmentDate!, scrollPercent, monthGroupPercentY);
+      void stopScrub?.({
+        scrubberMonth: segmentDate!,
+        overallScrollPercent: scrollPercent,
+        scrubberMonthScrollPercent: monthGroupPercentY,
+      });
      return;
    }

@@ -308,7 +335,11 @@
      return;
    }

-    void onScrub?.(segmentDate!, scrollPercent, monthGroupPercentY);
+    void onScrub?.({
+      scrubberMonth: segmentDate!,
+      overallScrollPercent: scrollPercent,
+      scrubberMonthScrollPercent: monthGroupPercentY,
+    });
  };
  /* eslint-disable tscompat/tscompat */
  const getTouch = (event: TouchEvent) => {
@@ -412,7 +443,11 @@
      }
      if (next) {
        event.preventDefault();
-        void onScrub?.({ year: next.year, month: next.month }, -1, 0);
+        void onScrub?.({
+          scrubberMonth: { year: next.year, month: next.month },
+          overallScrollPercent: -1,
+          scrubberMonthScrollPercent: 0,
+        });
        return true;
      }
    }
@@ -422,7 +457,11 @@
        const next = segments[idx + 1];
        if (next) {
          event.preventDefault();
-          void onScrub?.({ year: next.year, month: next.month }, -1, 0);
+          void onScrub?.({
+            scrubberMonth: { year: next.year, month: next.month },
+            overallScrollPercent: -1,
+            scrubberMonthScrollPercent: 0,
+          });
          return true;
        }
      }
--- a/web/src/lib/components/timeline/Timeline.svelte
+++ b/web/src/lib/components/timeline/Timeline.svelte
@@ -1,46 +1,36 @@
 <script lang="ts">
-  import { afterNavigate, beforeNavigate, goto } from '$app/navigation';
+  import { afterNavigate, beforeNavigate } from '$app/navigation';
  import { page } from '$app/stores';
  import { resizeObserver, type OnResizeCallback } from '$lib/actions/resize-observer';
-  import { shortcuts, type ShortcutOptions } from '$lib/actions/shortcut';
-  import type { Action } from '$lib/components/asset-viewer/actions/action';
-  import type { AbsoluteResult, RelativeResult } from '$lib/components/shared-components/change-date.svelte';
-  import ChangeDate from '$lib/components/shared-components/change-date.svelte';
+  import Thumbnail from '$lib/components/assets/thumbnail/thumbnail.svelte';
+  import MonthSegment from '$lib/components/timeline/MonthSegment.svelte';
  import Scrubber from '$lib/components/timeline/Scrubber.svelte';
-  import {
-    setFocusToAsset as setFocusAssetInit,
-    setFocusTo as setFocusToInit,
-  } from '$lib/components/timeline/actions/focus-actions';
-  import { AppRoute, AssetAction } from '$lib/constants';
+  import TimelineAssetViewer from '$lib/components/timeline/TimelineAssetViewer.svelte';
+  import TimelineKeyboardActions from '$lib/components/timeline/actions/TimelineKeyboardActions.svelte';
+  import { AssetAction } from '$lib/constants';
  import HotModuleReload from '$lib/elements/HotModuleReload.svelte';
  import Portal from '$lib/elements/Portal.svelte';
  import Skeleton from '$lib/elements/Skeleton.svelte';
-  import { authManager } from '$lib/managers/auth-manager.svelte';
  import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
  import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
  import { assetsSnapshot } from '$lib/managers/timeline-manager/utils.svelte';
-  import ShortcutsModal from '$lib/modals/ShortcutsModal.svelte';
  import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
  import { assetViewingStore } from '$lib/stores/asset-viewing.store';
  import { isSelectingAllAssets } from '$lib/stores/assets-store.svelte';
  import { mobileDevice } from '$lib/stores/mobile-device.svelte';
-  import { showDeleteModal } from '$lib/stores/preferences.store';
-  import { searchStore } from '$lib/stores/search.svelte';
-  import { featureFlags } from '$lib/stores/server-config.store';
-  import { handlePromiseError } from '$lib/utils';
-  import { deleteAssets, updateStackedAssetInTimeline, updateUnstackedAssetInTimeline } from '$lib/utils/actions';
-  import { archiveAssets, cancelMultiselect, selectAllAssets, stackAssets } from '$lib/utils/asset-utils';
  import { navigate } from '$lib/utils/navigation';
-  import { getTimes, toTimelineAsset, type ScrubberListener, type TimelineYearMonth } from '$lib/utils/timeline-util';
-  import { AssetVisibility, getAssetInfo, type AlbumResponseDto, type PersonResponseDto } from '@immich/sdk';
-  import { modalManager } from '@immich/ui';
+  import {
+    getSegmentIdentifier,
+    getTimes,
+    type ScrubberListener,
+    type TimelineYearMonth,
+  } from '$lib/utils/timeline-util';
+  import { type AlbumResponseDto, type PersonResponseDto } from '@immich/sdk';
  import { DateTime } from 'luxon';
  import { onMount, type Snippet } from 'svelte';
  import type { UpdatePayload } from 'vite';
-  import DeleteAssetDialog from '../photos-page/delete-asset-dialog.svelte';
-  import TimelineDateGroup from './TimelineDateGroup.svelte';

  interface Props {
    isSelectionMode?: boolean;
@@ -68,7 +58,7 @@
    onEscape?: () => void;
    children?: Snippet;
    empty?: Snippet;
-    customLayout?: Snippet<[TimelineAsset]>;
+    customThumbnailLayout?: Snippet<[TimelineAsset]>;
    onThumbnailClick?: (
      asset: TimelineAsset,
      timelineManager: TimelineManager,
@@ -99,26 +89,31 @@
    onEscape = () => {},
    children,
    empty,
-    customLayout,
+    customThumbnailLayout,
    onThumbnailClick,
  }: Props = $props();

-  let { isViewing: showAssetViewer, asset: viewingAsset, preloadAssets, gridScrollTarget, mutex } = assetViewingStore;
+  let { isViewing: showAssetViewer, asset: viewingAsset, gridScrollTarget } = assetViewingStore;

  let element: HTMLElement | undefined = $state();

  let timelineElement: HTMLElement | undefined = $state();
  let showSkeleton = $state(true);
-  let isShowSelectDate = $state(false);
-  let scrubberMonthPercent = $state(0);
-  let scrubberMonth: { year: number; month: number } | undefined = $state(undefined);
-  let scrubOverallPercent: number = $state(0);
+  // The percentage of scroll through the month that is currently intersecting the top boundary of the viewport.
+  // Note: There may be multiple months visible within the viewport at any given time.
+  let viewportTopMonthScrollPercent = $state(0);
+  // The timeline month intersecting the top position of the viewport
+  let viewportTopMonth: { year: number; month: number } | undefined = $state(undefined);
+  // Overall scroll percentage through the entire timeline (0-1)
+  let timelineScrollPercent: number = $state(0);
  let scrubberWidth = $state(0);

  // 60 is the bottom spacer element at 60px
  let bottomSectionHeight = 60;
-  let leadout = $state(false);
+  // Indicates whether the viewport is currently in the lead-out section (after all months)
+  let isInLeadOutSection = $state(false);

+  const isEmpty = $derived(timelineManager.isInitialized && timelineManager.months.length === 0);
  const maxMd = $derived(mobileDevice.maxMd);
  const usingMobileDevice = $derived(mobileDevice.pointerCoarse);

@@ -301,20 +296,19 @@
    scrollTop(scrollToTop);
  };

-  // note: don't throttle, debounch, or otherwise make this function async - it causes flicker
-  const onScrub: ScrubberListener = (
-    scrubMonth: { year: number; month: number },
-    overallScrollPercent: number,
-    scrubberMonthScrollPercent: number,
-  ) => {
-    if (!scrubMonth || timelineManager.timelineHeight < timelineManager.viewportHeight * 2) {
+  // note: don't throttle, debounce, or otherwise make this function async - it causes flicker
+  // this function scrolls the timeline to the specified month group and offset, based on scrubber interaction
+  const onScrub: ScrubberListener = (scrubberData) => {
+    const { scrubberMonth, overallScrollPercent, scrubberMonthScrollPercent } = scrubberData;
+
+    if (!scrubberMonth || timelineManager.timelineHeight < timelineManager.viewportHeight * 2) {
      // edge case - scroll limited due to size of content, must adjust - use use the overall percent instead
      const maxScroll = getMaxScroll();
      const offset = maxScroll * overallScrollPercent;
      scrollTop(offset);
    } else {
      const monthGroup = timelineManager.months.find(
-        ({ yearMonth: { year, month } }) => year === scrubMonth.year && month === scrubMonth.month,
+        ({ yearMonth: { year, month } }) => year === scrubberMonth.year && month === scrubberMonth.month,
      );
      if (!monthGroup) {
        return;
@@ -325,7 +319,7 @@

  // note: don't throttle, debounch, or otherwise make this function async - it causes flicker
  const handleTimelineScroll = () => {
-    leadout = false;
+    isInLeadOutSection = false;

    if (!element) {
      return;
@@ -334,19 +328,19 @@
    if (timelineManager.timelineHeight < timelineManager.viewportHeight * 2) {
      // edge case - scroll limited due to size of content, must adjust -  use the overall percent instead
      const maxScroll = getMaxScroll();
-      scrubOverallPercent = Math.min(1, element.scrollTop / maxScroll);
+      timelineScrollPercent = Math.min(1, element.scrollTop / maxScroll);

-      scrubberMonth = undefined;
-      scrubberMonthPercent = 0;
+      viewportTopMonth = undefined;
+      viewportTopMonthScrollPercent = 0;
    } else {
      let top = element.scrollTop;
      if (top < timelineManager.topSectionHeight) {
        // in the lead-in area
-        scrubberMonth = undefined;
-        scrubberMonthPercent = 0;
+        viewportTopMonth = undefined;
+        viewportTopMonthScrollPercent = 0;
        const maxScroll = getMaxScroll();

-        scrubOverallPercent = Math.min(1, element.scrollTop / maxScroll);
+        timelineScrollPercent = Math.min(1, element.scrollTop / maxScroll);
        return;
      }

@@ -371,15 +365,15 @@
        let next = top - monthGroupHeight * maxScrollPercent;
        // instead of checking for < 0, add a little wiggle room for subpixel resolution
        if (next < -1 && monthGroup) {
-          scrubberMonth = monthGroup;
+          viewportTopMonth = monthGroup;

          // allowing next to be at least 1 may cause percent to go negative, so ensure positive percentage
-          scrubberMonthPercent = Math.max(0, top / (monthGroupHeight * maxScrollPercent));
+          viewportTopMonthScrollPercent = Math.max(0, top / (monthGroupHeight * maxScrollPercent));

          // compensate for lost precision/rounding errors advance to the next bucket, if present
-          if (scrubberMonthPercent > 0.9999 && i + 1 < monthsLength - 1) {
-            scrubberMonth = timelineManager.months[i + 1].yearMonth;
-            scrubberMonthPercent = 0;
+          if (viewportTopMonthScrollPercent > 0.9999 && i + 1 < monthsLength - 1) {
+            viewportTopMonth = timelineManager.months[i + 1].yearMonth;
+            viewportTopMonthScrollPercent = 0;
          }

          found = true;
@@ -388,200 +382,25 @@
        top = next;
      }
      if (!found) {
-        leadout = true;
-        scrubberMonth = undefined;
-        scrubberMonthPercent = 0;
-        scrubOverallPercent = 1;
+        isInLeadOutSection = true;
+        viewportTopMonth = undefined;
+        viewportTopMonthScrollPercent = 0;
+        timelineScrollPercent = 1;
      }
    }
  };

-  const trashOrDelete = async (force: boolean = false) => {
-    isShowDeleteConfirmation = false;
-    await deleteAssets(
-      !(isTrashEnabled && !force),
-      (assetIds) => timelineManager.removeAssets(assetIds),
-      assetInteraction.selectedAssets,
-      !isTrashEnabled || force ? undefined : (assets) => timelineManager.addAssets(assets),
-    );
-    assetInteraction.clearMultiselect();
-  };
-
-  const onDelete = () => {
-    const hasTrashedAsset = assetInteraction.selectedAssets.some((asset) => asset.isTrashed);
-
-    if ($showDeleteModal && (!isTrashEnabled || hasTrashedAsset)) {
-      isShowDeleteConfirmation = true;
-      return;
-    }
-    handlePromiseError(trashOrDelete(hasTrashedAsset));
-  };
-
-  const onForceDelete = () => {
-    if ($showDeleteModal) {
-      isShowDeleteConfirmation = true;
-      return;
-    }
-    handlePromiseError(trashOrDelete(true));
-  };
-
-  const onStackAssets = async () => {
-    const result = await stackAssets(assetInteraction.selectedAssets);
-
-    updateStackedAssetInTimeline(timelineManager, result);
-
-    onEscape();
-  };
-
-  const toggleArchive = async () => {
-    const visibility = assetInteraction.isAllArchived ? AssetVisibility.Timeline : AssetVisibility.Archive;
-    const ids = await archiveAssets(assetInteraction.selectedAssets, visibility);
-    timelineManager.updateAssetOperation(ids, (asset) => {
-      asset.visibility = visibility;
-      return { remove: false };
-    });
-    deselectAllAssets();
-  };
-
  const handleSelectAsset = (asset: TimelineAsset) => {
    if (!timelineManager.albumAssets.has(asset.id)) {
      assetInteraction.selectAsset(asset);
    }
  };

-  const handlePrevious = async () => {
-    const release = await mutex.acquire();
-    const laterAsset = await timelineManager.getLaterAsset($viewingAsset);
-
-    if (laterAsset) {
-      const preloadAsset = await timelineManager.getLaterAsset(laterAsset);
-      const asset = await getAssetInfo({ ...authManager.params, id: laterAsset.id });
-      assetViewingStore.setAsset(asset, preloadAsset ? [preloadAsset] : []);
-      await navigate({ targetRoute: 'current', assetId: laterAsset.id });
-    }
-
-    release();
-    return !!laterAsset;
-  };
-
-  const handleNext = async () => {
-    const release = await mutex.acquire();
-    const earlierAsset = await timelineManager.getEarlierAsset($viewingAsset);
-
-    if (earlierAsset) {
-      const preloadAsset = await timelineManager.getEarlierAsset(earlierAsset);
-      const asset = await getAssetInfo({ ...authManager.params, id: earlierAsset.id });
-      assetViewingStore.setAsset(asset, preloadAsset ? [preloadAsset] : []);
-      await navigate({ targetRoute: 'current', assetId: earlierAsset.id });
-    }
-
-    release();
-    return !!earlierAsset;
-  };
-
-  const handleRandom = async () => {
-    const randomAsset = await timelineManager.getRandomAsset();
-
-    if (randomAsset) {
-      const asset = await getAssetInfo({ ...authManager.params, id: randomAsset.id });
-      assetViewingStore.setAsset(asset);
-      await navigate({ targetRoute: 'current', assetId: randomAsset.id });
-      return asset;
-    }
-  };
-
-  const handleClose = async (asset: { id: string }) => {
-    assetViewingStore.showAssetViewer(false);
-    showSkeleton = true;
-    $gridScrollTarget = { at: asset.id };
-    await navigate({ targetRoute: 'current', assetId: null, assetGridRouteSearchParams: $gridScrollTarget });
-  };
-
-  const handlePreAction = async (action: Action) => {
-    switch (action.type) {
-      case removeAction:
-      case AssetAction.TRASH:
-      case AssetAction.RESTORE:
-      case AssetAction.DELETE:
-      case AssetAction.ARCHIVE:
-      case AssetAction.SET_VISIBILITY_LOCKED:
-      case AssetAction.SET_VISIBILITY_TIMELINE: {
-        // find the next asset to show or close the viewer
-        // eslint-disable-next-line @typescript-eslint/no-unused-expressions
-        (await handleNext()) || (await handlePrevious()) || (await handleClose(action.asset));
-
-        // delete after find the next one
-        timelineManager.removeAssets([action.asset.id]);
-        break;
-      }
-    }
-  };
-  const handleAction = (action: Action) => {
-    switch (action.type) {
-      case AssetAction.ARCHIVE:
-      case AssetAction.UNARCHIVE:
-      case AssetAction.FAVORITE:
-      case AssetAction.UNFAVORITE: {
-        timelineManager.updateAssets([action.asset]);
-        break;
-      }
-
-      case AssetAction.ADD: {
-        timelineManager.addAssets([action.asset]);
-        break;
-      }
-
-      case AssetAction.UNSTACK: {
-        updateUnstackedAssetInTimeline(timelineManager, action.assets);
-        break;
-      }
-      case AssetAction.REMOVE_ASSET_FROM_STACK: {
-        timelineManager.addAssets([toTimelineAsset(action.asset)]);
-        if (action.stack) {
-          //Have to unstack then restack assets in timeline in order to update the stack count in the timeline.
-          updateUnstackedAssetInTimeline(
-            timelineManager,
-            action.stack.assets.map((asset) => toTimelineAsset(asset)),
-          );
-          updateStackedAssetInTimeline(timelineManager, {
-            stack: action.stack,
-            toDeleteIds: action.stack.assets
-              .filter((asset) => asset.id !== action.stack?.primaryAssetId)
-              .map((asset) => asset.id),
-          });
-        }
-        break;
-      }
-      case AssetAction.SET_STACK_PRIMARY_ASSET: {
-        //Have to unstack then restack assets in timeline in order for the currently removed new primary asset to be made visible.
-        updateUnstackedAssetInTimeline(
-          timelineManager,
-          action.stack.assets.map((asset) => toTimelineAsset(asset)),
-        );
-        updateStackedAssetInTimeline(timelineManager, {
-          stack: action.stack,
-          toDeleteIds: action.stack.assets
-            .filter((asset) => asset.id !== action.stack.primaryAssetId)
-            .map((asset) => asset.id),
-        });
-        break;
-      }
-    }
-  };
-
  let lastAssetMouseEvent: TimelineAsset | null = $state(null);

  let shiftKeyIsDown = $state(false);

-  const deselectAllAssets = () => {
-    cancelMultiselect(assetInteraction);
-  };
-
  const onKeyDown = (event: KeyboardEvent) => {
-    if (searchStore.isSearchEnabled) {
-      return;
-    }
-
    if (event.key === 'Shift') {
      event.preventDefault();
      shiftKeyIsDown = true;
@@ -589,16 +408,11 @@
  };

  const onKeyUp = (event: KeyboardEvent) => {
-    if (searchStore.isSearchEnabled) {
-      return;
-    }
-
    if (event.key === 'Shift') {
      event.preventDefault();
      shiftKeyIsDown = false;
    }
  };
-
  const handleSelectAssetCandidates = (asset: TimelineAsset | null) => {
    if (asset) {
      void selectAssetCandidates(asset);
@@ -606,7 +420,8 @@
    lastAssetMouseEvent = asset;
  };

-  const handleGroupSelect = (timelineManager: TimelineManager, group: string, assets: TimelineAsset[]) => {
+  const handleGroupSelect = (dayGroup: DayGroup, assets: TimelineAsset[]) => {
+    const group = dayGroup.groupTitle;
    if (assetInteraction.selectedGroup.has(group)) {
      assetInteraction.removeGroupFromMultiselectGroup(group);
      for (const asset of assets) {
@@ -626,7 +441,7 @@
    }
  };

-  const handleSelectAssets = async (asset: TimelineAsset) => {
+  const onSelectAssets = async (asset: TimelineAsset) => {
    if (!asset) {
      return;
    }
@@ -670,7 +485,7 @@
          break;
        }
        if (started) {
-          await timelineManager.loadMonthGroup(monthGroup.yearMonth);
+          await timelineManager.loadSegment(monthGroup.identifier);
          for (const asset of monthGroup.assetsIterator()) {
            if (deselect) {
              assetInteraction.removeAssetFromMultiselectGroup(asset.id);
@@ -724,72 +539,6 @@
    assetInteraction.setAssetSelectionCandidates(assets);
  };

-  const onSelectStart = (e: Event) => {
-    if (assetInteraction.selectionActive && shiftKeyIsDown) {
-      e.preventDefault();
-    }
-  };
-
-  let isTrashEnabled = $derived($featureFlags.loaded && $featureFlags.trash);
-  let isEmpty = $derived(timelineManager.isInitialized && timelineManager.months.length === 0);
-  let idsSelectedAssets = $derived(assetInteraction.selectedAssets.map(({ id }) => id));
-  let isShortcutModalOpen = false;
-
-  const handleOpenShortcutModal = async () => {
-    if (isShortcutModalOpen) {
-      return;
-    }
-
-    isShortcutModalOpen = true;
-    await modalManager.show(ShortcutsModal, {});
-    isShortcutModalOpen = false;
-  };
-
-  $effect(() => {
-    if (isEmpty) {
-      assetInteraction.clearMultiselect();
-    }
-  });
-
-  const setFocusTo = setFocusToInit.bind(undefined, scrollToAsset, timelineManager);
-  const setFocusAsset = setFocusAssetInit.bind(undefined, scrollToAsset);
-
-  let shortcutList = $derived(
-    (() => {
-      if (searchStore.isSearchEnabled || $showAssetViewer) {
-        return [];
-      }
-
-      const shortcuts: ShortcutOptions[] = [
-        { shortcut: { key: 'Escape' }, onShortcut: onEscape },
-        { shortcut: { key: '?', shift: true }, onShortcut: handleOpenShortcutModal },
-        { shortcut: { key: '/' }, onShortcut: () => goto(AppRoute.EXPLORE) },
-        { shortcut: { key: 'A', ctrl: true }, onShortcut: () => selectAllAssets(timelineManager, assetInteraction) },
-        { shortcut: { key: 'ArrowRight' }, onShortcut: () => setFocusTo('earlier', 'asset') },
-        { shortcut: { key: 'ArrowLeft' }, onShortcut: () => setFocusTo('later', 'asset') },
-        { shortcut: { key: 'D' }, onShortcut: () => setFocusTo('earlier', 'day') },
-        { shortcut: { key: 'D', shift: true }, onShortcut: () => setFocusTo('later', 'day') },
-        { shortcut: { key: 'M' }, onShortcut: () => setFocusTo('earlier', 'month') },
-        { shortcut: { key: 'M', shift: true }, onShortcut: () => setFocusTo('later', 'month') },
-        { shortcut: { key: 'Y' }, onShortcut: () => setFocusTo('earlier', 'year') },
-        { shortcut: { key: 'Y', shift: true }, onShortcut: () => setFocusTo('later', 'year') },
-        { shortcut: { key: 'G' }, onShortcut: () => (isShowSelectDate = true) },
-      ];
-
-      if (assetInteraction.selectionActive) {
-        shortcuts.push(
-          { shortcut: { key: 'Delete' }, onShortcut: onDelete },
-          { shortcut: { key: 'Delete', shift: true }, onShortcut: onForceDelete },
-          { shortcut: { key: 'D', ctrl: true }, onShortcut: () => deselectAllAssets() },
-          { shortcut: { key: 's' }, onShortcut: () => onStackAssets() },
-          { shortcut: { key: 'a', shift: true }, onShortcut: toggleArchive },
-        );
-      }
-
-      return shortcuts;
-    })(),
-  );
-
  $effect(() => {
    if (!lastAssetMouseEvent) {
      assetInteraction.clearAssetSelectionCandidates();
@@ -811,42 +560,62 @@
  $effect(() => {
    if ($showAssetViewer) {
      const { localDateTime } = getTimes($viewingAsset.fileCreatedAt, DateTime.local().offset / 60);
-      void timelineManager.loadMonthGroup({ year: localDateTime.year, month: localDateTime.month });
+      void timelineManager.loadSegment(getSegmentIdentifier({ year: localDateTime.year, month: localDateTime.month }));
    }
  });
+
+  const assetSelectHandler = (
+    timelineManager: TimelineManager,
+    asset: TimelineAsset,
+    assetsInDayGroup: TimelineAsset[],
+    groupTitle: string,
+  ) => {
+    void onSelectAssets(asset);
+
+    // Check if all assets are selected in a group to toggle the group selection's icon
+    let selectedAssetsInGroupCount = assetsInDayGroup.filter((asset) =>
+      assetInteraction.hasSelectedAsset(asset.id),
+    ).length;
+
+    // if all assets are selected in a group, add the group to selected group
+    if (selectedAssetsInGroupCount == assetsInDayGroup.length) {
+      assetInteraction.addGroupToMultiselectGroup(groupTitle);
+    } else {
+      assetInteraction.removeGroupFromMultiselectGroup(groupTitle);
+    }
+
+    if (timelineManager.assetCount == assetInteraction.selectedAssets.length) {
+      isSelectingAllAssets.set(true);
+    } else {
+      isSelectingAllAssets.set(false);
+    }
+  };
+
+  const _onClick = (
+    timelineManager: TimelineManager,
+    assets: TimelineAsset[],
+    groupTitle: string,
+    asset: TimelineAsset,
+  ) => {
+    if (isSelectionMode || assetInteraction.selectionActive) {
+      assetSelectHandler(timelineManager, asset, assets, groupTitle);
+      return;
+    }
+    void navigate({ targetRoute: 'current', assetId: asset.id });
+  };
 </script>

-<svelte:document onkeydown={onKeyDown} onkeyup={onKeyUp} onselectstart={onSelectStart} use:shortcuts={shortcutList} />
+<svelte:document onkeydown={onKeyDown} onkeyup={onKeyUp} />

 <HotModuleReload onAfterUpdate={handleAfterUpdate} onBeforeUpdate={handleBeforeUpdate} />

-{#if isShowDeleteConfirmation}
-  <DeleteAssetDialog
-    size={idsSelectedAssets.length}
-    onCancel={() => (isShowDeleteConfirmation = false)}
-    onConfirm={() => handlePromiseError(trashOrDelete(true))}
-  />
-{/if}
-
-{#if isShowSelectDate}
-  <ChangeDate
-    title="Navigate to Time"
-    initialDate={DateTime.now()}
-    timezoneInput={false}
-    onConfirm={async (dateString: AbsoluteResult | RelativeResult) => {
-      isShowSelectDate = false;
-      if (dateString.mode == 'absolute') {
-        const asset = await timelineManager.getClosestAssetToDate(
-          (DateTime.fromISO(dateString.date) as DateTime<true>).toObject(),
-        );
-        if (asset) {
-          setFocusAsset(asset);
-        }
-      }
-    }}
-    onCancel={() => (isShowSelectDate = false)}
-  />
-{/if}
+<TimelineKeyboardActions
+  scrollToAsset={(asset) => scrollToAsset(asset) ?? false}
+  {timelineManager}
+  {assetInteraction}
+  bind:isShowDeleteConfirmation
+  {onEscape}
+/>

 {#if timelineManager.months.length > 0}
  <Scrubber
@@ -854,10 +623,10 @@
    height={timelineManager.viewportHeight}
    timelineTopOffset={timelineManager.topSectionHeight}
    timelineBottomOffset={bottomSectionHeight}
-    {leadout}
-    {scrubOverallPercent}
-    {scrubberMonthPercent}
-    {scrubberMonth}
+    {isInLeadOutSection}
+    {timelineScrollPercent}
+    {viewportTopMonthScrollPercent}
+    {viewportTopMonth}
    {onScrub}
    bind:scrubberWidth
    onScrubKeyDown={(evt) => {
@@ -933,21 +702,47 @@
          style:transform={`translate3d(0,${absoluteHeight}px,0)`}
          style:width="100%"
        >
-          <TimelineDateGroup
-            {withStacked}
-            {showArchiveIcon}
+          <MonthSegment
            {assetInteraction}
-            {timelineManager}
-            {isSelectionMode}
+            {customThumbnailLayout}
            {singleSelect}
            {monthGroup}
-            onSelect={({ title, assets }) => handleGroupSelect(timelineManager, title, assets)}
-            onSelectAssetCandidates={handleSelectAssetCandidates}
-            onSelectAssets={handleSelectAssets}
-            onScrollCompensation={handleScrollCompensation}
-            {customLayout}
-            {onThumbnailClick}
-          />
+            {timelineManager}
+            onDayGroupSelect={handleGroupSelect}
+          >
+            {#snippet thumbnail({ asset, position, dayGroup, groupIndex })}
+              {@const isAssetSelectionCandidate = assetInteraction.hasSelectionCandidate(asset.id)}
+              {@const isAssetSelected =
+                assetInteraction.hasSelectedAsset(asset.id) || timelineManager.albumAssets.has(asset.id)}
+              {@const isAssetDisabled = timelineManager.albumAssets.has(asset.id)}
+              <Thumbnail
+                showStackedIcon={withStacked}
+                {showArchiveIcon}
+                {asset}
+                {groupIndex}
+                onClick={(asset) => {
+                  if (typeof onThumbnailClick === 'function') {
+                    onThumbnailClick(asset, timelineManager, dayGroup, _onClick);
+                  } else {
+                    _onClick(timelineManager, dayGroup.getAssets(), dayGroup.groupTitle, asset);
+                  }
+                }}
+                onSelect={() => {
+                  if (isSelectionMode || assetInteraction.selectionActive) {
+                    assetSelectHandler(timelineManager, asset, dayGroup.getAssets(), dayGroup.groupTitle);
+                    return;
+                  }
+                  void onSelectAssets(asset);
+                }}
+                onMouseEvent={() => handleSelectAssetCandidates(asset)}
+                selected={isAssetSelected}
+                selectionCandidate={isAssetSelectionCandidate}
+                disabled={isAssetDisabled}
+                thumbnailWidth={position.width}
+                thumbnailHeight={position.height}
+              />
+            {/snippet}
+          </MonthSegment>
        </div>
      {/if}
    {/each}
@@ -964,22 +759,7 @@

 <Portal target="body">
  {#if $showAssetViewer}
-    {#await import('../asset-viewer/asset-viewer.svelte') then { default: AssetViewer }}
-      <AssetViewer
-        {withStacked}
-        asset={$viewingAsset}
-        preloadAssets={$preloadAssets}
-        {isShared}
-        {album}
-        {person}
-        preAction={handlePreAction}
-        onAction={handleAction}
-        onPrevious={handlePrevious}
-        onNext={handleNext}
-        onRandom={handleRandom}
-        onClose={handleClose}
-      />
-    {/await}
+    <TimelineAssetViewer bind:showSkeleton {timelineManager} {removeAction} {withStacked} {isShared} {album} {person} />
  {/if}
 </Portal>

--- a/web/src/lib/components/timeline/TimelineAssetViewer.svelte
+++ b/web/src/lib/components/timeline/TimelineAssetViewer.svelte
@@ -0,0 +1,177 @@
+<script lang="ts">
+  import type { Action } from '$lib/components/asset-viewer/actions/action';
+  import { AssetAction } from '$lib/constants';
+  import { authManager } from '$lib/managers/auth-manager.svelte';
+  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import { assetViewingStore } from '$lib/stores/asset-viewing.store';
+  import { updateStackedAssetInTimeline, updateUnstackedAssetInTimeline } from '$lib/utils/actions';
+  import { navigate } from '$lib/utils/navigation';
+  import { toTimelineAsset } from '$lib/utils/timeline-util';
+  import { getAssetInfo, type AlbumResponseDto, type PersonResponseDto } from '@immich/sdk';
+
+  let { asset: viewingAsset, gridScrollTarget, mutex, preloadAssets } = assetViewingStore;
+
+  interface Props {
+    timelineManager: TimelineManager;
+    showSkeleton: boolean;
+    withStacked?: boolean;
+    isShared?: boolean;
+    album?: AlbumResponseDto | null;
+    person?: PersonResponseDto | null;
+
+    removeAction?:
+      | AssetAction.UNARCHIVE
+      | AssetAction.ARCHIVE
+      | AssetAction.FAVORITE
+      | AssetAction.UNFAVORITE
+      | AssetAction.SET_VISIBILITY_TIMELINE
+      | null;
+  }
+
+  let {
+    timelineManager,
+    showSkeleton = $bindable(false),
+    removeAction,
+    withStacked = false,
+    isShared = false,
+    album = null,
+    person = null,
+  }: Props = $props();
+
+  const handlePrevious = async () => {
+    const release = await mutex.acquire();
+    const laterAsset = await timelineManager.getLaterAsset($viewingAsset);
+
+    if (laterAsset) {
+      const preloadAsset = await timelineManager.getLaterAsset(laterAsset);
+      const asset = await getAssetInfo({ ...authManager.params, id: laterAsset.id });
+      assetViewingStore.setAsset(asset, preloadAsset ? [preloadAsset] : []);
+      await navigate({ targetRoute: 'current', assetId: laterAsset.id });
+    }
+
+    release();
+    return !!laterAsset;
+  };
+
+  const handleNext = async () => {
+    const release = await mutex.acquire();
+    const earlierAsset = await timelineManager.getEarlierAsset($viewingAsset);
+
+    if (earlierAsset) {
+      const preloadAsset = await timelineManager.getEarlierAsset(earlierAsset);
+      const asset = await getAssetInfo({ ...authManager.params, id: earlierAsset.id });
+      assetViewingStore.setAsset(asset, preloadAsset ? [preloadAsset] : []);
+      await navigate({ targetRoute: 'current', assetId: earlierAsset.id });
+    }
+
+    release();
+    return !!earlierAsset;
+  };
+
+  const handleRandom = async () => {
+    const randomAsset = await timelineManager.getRandomAsset();
+
+    if (randomAsset) {
+      const asset = await getAssetInfo({ ...authManager.params, id: randomAsset.id });
+      assetViewingStore.setAsset(asset);
+      await navigate({ targetRoute: 'current', assetId: randomAsset.id });
+      return asset;
+    }
+  };
+
+  const handleClose = async (asset: { id: string }) => {
+    assetViewingStore.showAssetViewer(false);
+    showSkeleton = true;
+    $gridScrollTarget = { at: asset.id };
+    await navigate({ targetRoute: 'current', assetId: null, assetGridRouteSearchParams: $gridScrollTarget });
+  };
+
+  const handlePreAction = async (action: Action) => {
+    switch (action.type) {
+      case removeAction:
+      case AssetAction.TRASH:
+      case AssetAction.RESTORE:
+      case AssetAction.DELETE:
+      case AssetAction.ARCHIVE:
+      case AssetAction.SET_VISIBILITY_LOCKED:
+      case AssetAction.SET_VISIBILITY_TIMELINE: {
+        // find the next asset to show or close the viewer
+        // eslint-disable-next-line @typescript-eslint/no-unused-expressions
+        (await handleNext()) || (await handlePrevious()) || (await handleClose(action.asset));
+
+        // delete after find the next one
+        timelineManager.removeAssets([action.asset.id]);
+        break;
+      }
+    }
+  };
+  const handleAction = (action: Action) => {
+    switch (action.type) {
+      case AssetAction.ARCHIVE:
+      case AssetAction.UNARCHIVE:
+      case AssetAction.FAVORITE:
+      case AssetAction.UNFAVORITE: {
+        timelineManager.upsertAssets([action.asset]);
+        break;
+      }
+
+      case AssetAction.ADD: {
+        timelineManager.upsertAssets([action.asset]);
+        break;
+      }
+
+      case AssetAction.UNSTACK: {
+        updateUnstackedAssetInTimeline(timelineManager, action.assets);
+        break;
+      }
+      case AssetAction.REMOVE_ASSET_FROM_STACK: {
+        timelineManager.upsertAssets([toTimelineAsset(action.asset)]);
+        if (action.stack) {
+          //Have to unstack then restack assets in timeline in order to update the stack count in the timeline.
+          updateUnstackedAssetInTimeline(
+            timelineManager,
+            action.stack.assets.map((asset) => toTimelineAsset(asset)),
+          );
+          updateStackedAssetInTimeline(timelineManager, {
+            stack: action.stack,
+            toDeleteIds: action.stack.assets
+              .filter((asset) => asset.id !== action.stack?.primaryAssetId)
+              .map((asset) => asset.id),
+          });
+        }
+        break;
+      }
+      case AssetAction.SET_STACK_PRIMARY_ASSET: {
+        //Have to unstack then restack assets in timeline in order for the currently removed new primary asset to be made visible.
+        updateUnstackedAssetInTimeline(
+          timelineManager,
+          action.stack.assets.map((asset) => toTimelineAsset(asset)),
+        );
+        updateStackedAssetInTimeline(timelineManager, {
+          stack: action.stack,
+          toDeleteIds: action.stack.assets
+            .filter((asset) => asset.id !== action.stack.primaryAssetId)
+            .map((asset) => asset.id),
+        });
+        break;
+      }
+    }
+  };
+</script>
+
+{#await import('../asset-viewer/asset-viewer.svelte') then { default: AssetViewer }}
+  <AssetViewer
+    {withStacked}
+    asset={$viewingAsset}
+    preloadAssets={$preloadAssets}
+    {isShared}
+    {album}
+    {person}
+    preAction={handlePreAction}
+    onAction={handleAction}
+    onPrevious={handlePrevious}
+    onNext={handleNext}
+    onRandom={handleRandom}
+    onClose={handleClose}
+  />
+{/await}
--- a/web/src/lib/components/timeline/TimelineDateGroup.svelte
+++ b/web/src/lib/components/timeline/TimelineDateGroup.svelte
@@ -1,254 +0,0 @@
-<script lang="ts">
-  import Thumbnail from '$lib/components/assets/thumbnail/thumbnail.svelte';
-  import type { DayGroup } from '$lib/managers/timeline-manager/day-group.svelte';
-  import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
-  import type { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
-  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
-  import { assetSnapshot, assetsSnapshot } from '$lib/managers/timeline-manager/utils.svelte';
-  import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
-  import { isSelectingAllAssets } from '$lib/stores/assets-store.svelte';
-  import { uploadAssetsStore } from '$lib/stores/upload';
-  import { navigate } from '$lib/utils/navigation';
-
-  import { mdiCheckCircle, mdiCircleOutline } from '@mdi/js';
-
-  import { fromTimelinePlainDate, getDateLocaleString } from '$lib/utils/timeline-util';
-  import { Icon } from '@immich/ui';
-  import type { Snippet } from 'svelte';
-  import { flip } from 'svelte/animate';
-  import { scale } from 'svelte/transition';
-
-  let { isUploading } = uploadAssetsStore;
-
-  interface Props {
-    isSelectionMode: boolean;
-    singleSelect: boolean;
-    withStacked: boolean;
-    showArchiveIcon: boolean;
-    monthGroup: MonthGroup;
-    timelineManager: TimelineManager;
-    assetInteraction: AssetInteraction;
-    customLayout?: Snippet<[TimelineAsset]>;
-
-    onSelect: ({ title, assets }: { title: string; assets: TimelineAsset[] }) => void;
-    onSelectAssets: (asset: TimelineAsset) => void;
-    onSelectAssetCandidates: (asset: TimelineAsset | null) => void;
-    onScrollCompensation: (compensation: { heightDelta?: number; scrollTop?: number }) => void;
-    onThumbnailClick?: (
-      asset: TimelineAsset,
-      timelineManager: TimelineManager,
-      dayGroup: DayGroup,
-      onClick: (
-        timelineManager: TimelineManager,
-        assets: TimelineAsset[],
-        groupTitle: string,
-        asset: TimelineAsset,
-      ) => void,
-    ) => void;
-  }
-
-  let {
-    isSelectionMode,
-    singleSelect,
-    withStacked,
-    showArchiveIcon,
-    monthGroup = $bindable(),
-    assetInteraction,
-    timelineManager,
-    customLayout,
-    onSelect,
-    onSelectAssets,
-    onSelectAssetCandidates,
-    onScrollCompensation,
-    onThumbnailClick,
-  }: Props = $props();
-
-  let isMouseOverGroup = $state(false);
-  let hoveredDayGroup = $state();
-
-  const transitionDuration = $derived.by(() =>
-    monthGroup.timelineManager.suspendTransitions && !$isUploading ? 0 : 150,
-  );
-  const scaleDuration = $derived(transitionDuration === 0 ? 0 : transitionDuration + 100);
-  const _onClick = (
-    timelineManager: TimelineManager,
-    assets: TimelineAsset[],
-    groupTitle: string,
-    asset: TimelineAsset,
-  ) => {
-    if (isSelectionMode || assetInteraction.selectionActive) {
-      assetSelectHandler(timelineManager, asset, assets, groupTitle);
-      return;
-    }
-    void navigate({ targetRoute: 'current', assetId: asset.id });
-  };
-
-  const handleSelectGroup = (title: string, assets: TimelineAsset[]) => onSelect({ title, assets });
-
-  const assetSelectHandler = (
-    timelineManager: TimelineManager,
-    asset: TimelineAsset,
-    assetsInDayGroup: TimelineAsset[],
-    groupTitle: string,
-  ) => {
-    onSelectAssets(asset);
-
-    // Check if all assets are selected in a group to toggle the group selection's icon
-    let selectedAssetsInGroupCount = assetsInDayGroup.filter((asset) =>
-      assetInteraction.hasSelectedAsset(asset.id),
-    ).length;
-
-    // if all assets are selected in a group, add the group to selected group
-    if (selectedAssetsInGroupCount == assetsInDayGroup.length) {
-      assetInteraction.addGroupToMultiselectGroup(groupTitle);
-    } else {
-      assetInteraction.removeGroupFromMultiselectGroup(groupTitle);
-    }
-
-    if (timelineManager.assetCount == assetInteraction.selectedAssets.length) {
-      isSelectingAllAssets.set(true);
-    } else {
-      isSelectingAllAssets.set(false);
-    }
-  };
-
-  const assetMouseEventHandler = (groupTitle: string, asset: TimelineAsset | null) => {
-    // Show multi select icon on hover on date group
-    hoveredDayGroup = groupTitle;
-
-    if (assetInteraction.selectionActive) {
-      onSelectAssetCandidates(asset);
-    }
-  };
-
-  function filterIntersecting<R extends { intersecting: boolean }>(intersectable: R[]) {
-    return intersectable.filter((int) => int.intersecting);
-  }
-
-  const getDayGroupFullDate = (dayGroup: DayGroup): string => {
-    const { month, year } = dayGroup.monthGroup.yearMonth;
-    const date = fromTimelinePlainDate({
-      year,
-      month,
-      day: dayGroup.day,
-    });
-    return getDateLocaleString(date);
-  };
-
-  $effect.root(() => {
-    if (timelineManager.scrollCompensation.monthGroup === monthGroup) {
-      onScrollCompensation(timelineManager.scrollCompensation);
-      timelineManager.clearScrollCompensation();
-    }
-  });
-</script>
-
-{#each filterIntersecting(monthGroup.dayGroups) as dayGroup, groupIndex (dayGroup.day)}
-  {@const absoluteWidth = dayGroup.left}
-
-  <!-- svelte-ignore a11y_no_static_element_interactions -->
-  <section
-    class={[
-      { 'transition-all': !monthGroup.timelineManager.suspendTransitions },
-      !monthGroup.timelineManager.suspendTransitions && `delay-${transitionDuration}`,
-    ]}
-    data-group
-    style:position="absolute"
-    style:transform={`translate3d(${absoluteWidth}px,${dayGroup.top}px,0)`}
-    onmouseenter={() => {
-      isMouseOverGroup = true;
-      assetMouseEventHandler(dayGroup.groupTitle, null);
-    }}
-    onmouseleave={() => {
-      isMouseOverGroup = false;
-      assetMouseEventHandler(dayGroup.groupTitle, null);
-    }}
-  >
-    <!-- Date group title -->
-    <div
-      class="flex pt-7 pb-5 max-md:pt-5 max-md:pb-3 h-6 place-items-center text-xs font-medium text-immich-fg dark:text-immich-dark-fg md:text-sm"
-      style:width={dayGroup.width + 'px'}
-    >
-      {#if !singleSelect}
-        <div
-          class="hover:cursor-pointer transition-all duration-200 ease-out overflow-hidden w-0"
-          class:w-8={(hoveredDayGroup === dayGroup.groupTitle && isMouseOverGroup) ||
-            assetInteraction.selectedGroup.has(dayGroup.groupTitle)}
-          onclick={() => handleSelectGroup(dayGroup.groupTitle, assetsSnapshot(dayGroup.getAssets()))}
-          onkeydown={() => handleSelectGroup(dayGroup.groupTitle, assetsSnapshot(dayGroup.getAssets()))}
-        >
-          {#if assetInteraction.selectedGroup.has(dayGroup.groupTitle)}
-            <Icon icon={mdiCheckCircle} size="24" class="text-primary" />
-          {:else}
-            <Icon icon={mdiCircleOutline} size="24" color="#757575" />
-          {/if}
-        </div>
-      {/if}
-
-      <span class="w-full truncate first-letter:capitalize" title={getDayGroupFullDate(dayGroup)}>
-        {dayGroup.groupTitle}
-      </span>
-    </div>
-
-    <!-- Image grid -->
-    <div
-      data-image-grid
-      class="relative overflow-clip"
-      style:height={dayGroup.height + 'px'}
-      style:width={dayGroup.width + 'px'}
-    >
-      {#each filterIntersecting(dayGroup.viewerAssets) as viewerAsset (viewerAsset.id)}
-        {@const position = viewerAsset.position!}
-        {@const asset = viewerAsset.asset!}
-
-        <!-- {#if viewerAsset.intersecting} -->
-        <!-- note: don't remove data-asset-id - its used by web e2e tests -->
-        <div
-          data-asset-id={asset.id}
-          class="absolute"
-          style:top={position.top + 'px'}
-          style:left={position.left + 'px'}
-          style:width={position.width + 'px'}
-          style:height={position.height + 'px'}
-          out:scale|global={{ start: 0.1, duration: scaleDuration }}
-          animate:flip={{ duration: transitionDuration }}
-        >
-          <Thumbnail
-            showStackedIcon={withStacked}
-            {showArchiveIcon}
-            {asset}
-            {groupIndex}
-            onClick={(asset) => {
-              if (typeof onThumbnailClick === 'function') {
-                onThumbnailClick(asset, timelineManager, dayGroup, _onClick);
-              } else {
-                _onClick(timelineManager, dayGroup.getAssets(), dayGroup.groupTitle, asset);
-              }
-            }}
-            onSelect={(asset) => assetSelectHandler(timelineManager, asset, dayGroup.getAssets(), dayGroup.groupTitle)}
-            onMouseEvent={() => assetMouseEventHandler(dayGroup.groupTitle, assetSnapshot(asset))}
-            selected={assetInteraction.hasSelectedAsset(asset.id) ||
-              dayGroup.monthGroup.timelineManager.albumAssets.has(asset.id)}
-            selectionCandidate={assetInteraction.hasSelectionCandidate(asset.id)}
-            disabled={dayGroup.monthGroup.timelineManager.albumAssets.has(asset.id)}
-            thumbnailWidth={position.width}
-            thumbnailHeight={position.height}
-          />
-          {#if customLayout}
-            {@render customLayout(asset)}
-          {/if}
-        </div>
-        <!-- {/if} -->
-      {/each}
-    </div>
-  </section>
-{/each}
-
-<style>
-  section {
-    contain: layout paint style;
-  }
-  [data-image-grid] {
-    user-select: none;
-  }
-</style>
--- a/web/src/lib/components/timeline/actions/ArchiveAction.svelte
+++ b/web/src/lib/components/timeline/actions/ArchiveAction.svelte
@@ -1,5 +1,6 @@
 <script lang="ts">
  import { getAssetControlContext } from '$lib/components/timeline/AssetSelectControlBar.svelte';
+  import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
  import type { OnArchive } from '$lib/utils/actions';
  import { archiveAssets } from '$lib/utils/asset-utils';
  import { AssetVisibility } from '@immich/sdk';
@@ -12,9 +13,10 @@
    onArchive?: OnArchive;
    menuItem?: boolean;
    unarchive?: boolean;
+    manager?: PhotostreamManager;
  }

-  let { onArchive, menuItem = false, unarchive = false }: Props = $props();
+  let { onArchive, menuItem = false, unarchive = false, manager }: Props = $props();

  let text = $derived(unarchive ? $t('unarchive') : $t('to_archive'));
  let icon = $derived(unarchive ? mdiArchiveArrowUpOutline : mdiArchiveArrowDownOutline);
@@ -24,12 +26,13 @@
  const { clearSelect, getOwnedAssets } = getAssetControlContext();

  const handleArchive = async () => {
-    const isArchived = unarchive ? AssetVisibility.Timeline : AssetVisibility.Archive;
-    const assets = [...getOwnedAssets()].filter((asset) => asset.visibility !== isArchived);
+    const visibility = unarchive ? AssetVisibility.Timeline : AssetVisibility.Archive;
+    const assets = [...getOwnedAssets()].filter((asset) => asset.visibility !== visibility);
    loading = true;
-    const ids = await archiveAssets(assets, isArchived as AssetVisibility);
+    const ids = await archiveAssets(assets, visibility as AssetVisibility);
    if (ids) {
-      onArchive?.(ids, isArchived ? AssetVisibility.Archive : AssetVisibility.Timeline);
+      manager?.updateAssetOperation(ids, (asset) => ((asset.visibility = visibility), void 0));
+      onArchive?.(ids, visibility ? AssetVisibility.Archive : AssetVisibility.Timeline);
      clearSelect();
    }
    loading = false;
--- a/web/src/lib/components/timeline/actions/DeleteAssetsAction.svelte
+++ b/web/src/lib/components/timeline/actions/DeleteAssetsAction.svelte
@@ -1,6 +1,8 @@
 <script lang="ts">
  import DeleteAssetDialog from '$lib/components/photos-page/delete-asset-dialog.svelte';
  import { getAssetControlContext } from '$lib/components/timeline/AssetSelectControlBar.svelte';
+  import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
  import { featureFlags } from '$lib/stores/server-config.store';
  import { type OnDelete, type OnUndoDelete, deleteAssets } from '$lib/utils/actions';
  import { IconButton } from '@immich/ui';
@@ -9,13 +11,14 @@
  import MenuOption from '../../shared-components/context-menu/menu-option.svelte';

  interface Props {
-    onAssetDelete: OnDelete;
-    onUndoDelete?: OnUndoDelete | undefined;
+    onAssetDelete?: OnDelete;
+    onUndoDelete?: OnUndoDelete;
    menuItem?: boolean;
    force?: boolean;
+    manager?: PhotostreamManager;
  }

-  let { onAssetDelete, onUndoDelete = undefined, menuItem = false, force = !$featureFlags.trash }: Props = $props();
+  let { onAssetDelete, onUndoDelete, menuItem = false, force = !$featureFlags.trash, manager }: Props = $props();

  const { clearSelect, getOwnedAssets } = getAssetControlContext();

@@ -36,7 +39,12 @@
  const handleDelete = async () => {
    loading = true;
    const assets = [...getOwnedAssets()];
-    await deleteAssets(force, onAssetDelete, assets, onUndoDelete);
+    const undo = (assets: TimelineAsset[]) => {
+      manager?.upsertAssets(assets);
+      onUndoDelete?.(assets);
+    };
+    await deleteAssets(force, onAssetDelete, assets, undo);
+    manager?.removeAssets(assets.map((asset) => asset.id));
    clearSelect();
    isShowConfirmation = false;
    loading = false;
--- a/web/src/lib/components/timeline/actions/FavoriteAction.svelte
+++ b/web/src/lib/components/timeline/actions/FavoriteAction.svelte
@@ -5,6 +5,7 @@
    notificationController,
  } from '$lib/components/shared-components/notification/notification';
  import { getAssetControlContext } from '$lib/components/timeline/AssetSelectControlBar.svelte';
+  import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
  import type { OnFavorite } from '$lib/utils/actions';
  import { handleError } from '$lib/utils/handle-error';
  import { updateAssets } from '@immich/sdk';
@@ -16,9 +17,10 @@
    onFavorite?: OnFavorite;
    menuItem?: boolean;
    removeFavorite: boolean;
+    manager?: PhotostreamManager;
  }

-  let { onFavorite, menuItem = false, removeFavorite }: Props = $props();
+  let { onFavorite, menuItem = false, removeFavorite, manager }: Props = $props();

  let text = $derived(removeFavorite ? $t('remove_from_favorites') : $t('to_favorite'));
  let icon = $derived(removeFavorite ? mdiHeartMinusOutline : mdiHeartOutline);
@@ -39,11 +41,7 @@
      if (ids.length > 0) {
        await updateAssets({ assetBulkUpdateDto: { ids, isFavorite } });
      }
-
-      for (const asset of assets) {
-        asset.isFavorite = isFavorite;
-      }
-
+      manager?.updateAssetOperation(ids, (asset) => ((asset.isFavorite = isFavorite), void 0));
      onFavorite?.(ids, isFavorite);

      notificationController.show({
--- a/web/src/lib/components/timeline/actions/TimelineKeyboardActions.svelte
+++ b/web/src/lib/components/timeline/actions/TimelineKeyboardActions.svelte
@@ -0,0 +1,221 @@
+<script lang="ts">
+  import { goto } from '$app/navigation';
+  import { shortcuts, type ShortcutOptions } from '$lib/actions/shortcut';
+  import DeleteAssetDialog from '$lib/components/photos-page/delete-asset-dialog.svelte';
+  import ChangeDate, {
+    type AbsoluteResult,
+    type RelativeResult,
+  } from '$lib/components/shared-components/change-date.svelte';
+  import {
+    setFocusToAsset as setFocusAssetInit,
+    setFocusTo as setFocusToInit,
+  } from '$lib/components/timeline/actions/focus-actions';
+  import { AppRoute } from '$lib/constants';
+  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
+  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
+  import ShortcutsModal from '$lib/modals/ShortcutsModal.svelte';
+  import type { AssetInteraction } from '$lib/stores/asset-interaction.svelte';
+  import { assetViewingStore } from '$lib/stores/asset-viewing.store';
+  import { showDeleteModal } from '$lib/stores/preferences.store';
+  import { searchStore } from '$lib/stores/search.svelte';
+  import { featureFlags } from '$lib/stores/server-config.store';
+  import { handlePromiseError } from '$lib/utils';
+  import { deleteAssets, updateStackedAssetInTimeline } from '$lib/utils/actions';
+  import { archiveAssets, cancelMultiselect, selectAllAssets, stackAssets } from '$lib/utils/asset-utils';
+  import { AssetVisibility } from '@immich/sdk';
+  import { modalManager } from '@immich/ui';
+  import { DateTime } from 'luxon';
+  let { isViewing: showAssetViewer } = assetViewingStore;
+
+  interface Props {
+    timelineManager: TimelineManager;
+    assetInteraction: AssetInteraction;
+    isShowDeleteConfirmation: boolean;
+    onEscape?: () => void;
+    scrollToAsset: (asset: TimelineAsset) => boolean;
+  }
+
+  let {
+    timelineManager = $bindable(),
+    assetInteraction,
+    isShowDeleteConfirmation = $bindable(false),
+    onEscape,
+    scrollToAsset,
+  }: Props = $props();
+
+  let isShowSelectDate = $state(false);
+
+  const trashOrDelete = async (force: boolean = false) => {
+    isShowDeleteConfirmation = false;
+    await deleteAssets(
+      !(isTrashEnabled && !force),
+      (assetIds) => timelineManager.removeAssets(assetIds),
+      assetInteraction.selectedAssets,
+      !isTrashEnabled || force ? undefined : (assets) => timelineManager.upsertAssets(assets),
+    );
+    assetInteraction.clearMultiselect();
+  };
+
+  const onDelete = () => {
+    const hasTrashedAsset = assetInteraction.selectedAssets.some((asset) => asset.isTrashed);
+
+    if ($showDeleteModal && (!isTrashEnabled || hasTrashedAsset)) {
+      isShowDeleteConfirmation = true;
+      return;
+    }
+    handlePromiseError(trashOrDelete(hasTrashedAsset));
+  };
+
+  const onForceDelete = () => {
+    if ($showDeleteModal) {
+      isShowDeleteConfirmation = true;
+      return;
+    }
+    handlePromiseError(trashOrDelete(true));
+  };
+
+  const onStackAssets = async () => {
+    const result = await stackAssets(assetInteraction.selectedAssets);
+
+    updateStackedAssetInTimeline(timelineManager, result);
+
+    onEscape?.();
+  };
+
+  const toggleArchive = async () => {
+    const visibility = assetInteraction.isAllArchived ? AssetVisibility.Timeline : AssetVisibility.Archive;
+    const ids = await archiveAssets(assetInteraction.selectedAssets, visibility);
+    timelineManager.updateAssetOperation(ids, (asset) => {
+      asset.visibility = visibility;
+      return { remove: false };
+    });
+    deselectAllAssets();
+  };
+
+  let shiftKeyIsDown = $state(false);
+
+  const deselectAllAssets = () => {
+    cancelMultiselect(assetInteraction);
+  };
+
+  const onKeyDown = (event: KeyboardEvent) => {
+    if (searchStore.isSearchEnabled) {
+      return;
+    }
+
+    if (event.key === 'Shift') {
+      event.preventDefault();
+      shiftKeyIsDown = true;
+    }
+  };
+
+  const onKeyUp = (event: KeyboardEvent) => {
+    if (searchStore.isSearchEnabled) {
+      return;
+    }
+
+    if (event.key === 'Shift') {
+      event.preventDefault();
+      shiftKeyIsDown = false;
+    }
+  };
+
+  const onSelectStart = (e: Event) => {
+    if (assetInteraction.selectionActive && shiftKeyIsDown) {
+      e.preventDefault();
+    }
+  };
+
+  const isTrashEnabled = $derived($featureFlags.loaded && $featureFlags.trash);
+  const isEmpty = $derived(timelineManager.isInitialized && timelineManager.months.length === 0);
+  const idsSelectedAssets = $derived(assetInteraction.selectedAssets.map(({ id }) => id));
+  let isShortcutModalOpen = false;
+
+  const handleOpenShortcutModal = async () => {
+    if (isShortcutModalOpen) {
+      return;
+    }
+
+    isShortcutModalOpen = true;
+    await modalManager.show(ShortcutsModal, {});
+    isShortcutModalOpen = false;
+  };
+
+  $effect(() => {
+    if (isEmpty) {
+      assetInteraction.clearMultiselect();
+    }
+  });
+
+  const setFocusTo = setFocusToInit.bind(undefined, scrollToAsset, timelineManager);
+  const setFocusAsset = setFocusAssetInit.bind(undefined, scrollToAsset);
+
+  let shortcutList = $derived(
+    (() => {
+      if (searchStore.isSearchEnabled || $showAssetViewer) {
+        return [];
+      }
+
+      const shortcuts: ShortcutOptions[] = [
+        { shortcut: { key: '?', shift: true }, onShortcut: handleOpenShortcutModal },
+        { shortcut: { key: '/' }, onShortcut: () => goto(AppRoute.EXPLORE) },
+        { shortcut: { key: 'A', ctrl: true }, onShortcut: () => selectAllAssets(timelineManager, assetInteraction) },
+        { shortcut: { key: 'ArrowRight' }, onShortcut: () => setFocusTo('earlier', 'asset') },
+        { shortcut: { key: 'ArrowLeft' }, onShortcut: () => setFocusTo('later', 'asset') },
+        { shortcut: { key: 'D' }, onShortcut: () => setFocusTo('earlier', 'day') },
+        { shortcut: { key: 'D', shift: true }, onShortcut: () => setFocusTo('later', 'day') },
+        { shortcut: { key: 'M' }, onShortcut: () => setFocusTo('earlier', 'month') },
+        { shortcut: { key: 'M', shift: true }, onShortcut: () => setFocusTo('later', 'month') },
+        { shortcut: { key: 'Y' }, onShortcut: () => setFocusTo('earlier', 'year') },
+        { shortcut: { key: 'Y', shift: true }, onShortcut: () => setFocusTo('later', 'year') },
+        { shortcut: { key: 'G' }, onShortcut: () => (isShowSelectDate = true) },
+      ];
+      if (onEscape) {
+        shortcuts.push({ shortcut: { key: 'Escape' }, onShortcut: onEscape });
+      }
+
+      if (assetInteraction.selectionActive) {
+        shortcuts.push(
+          { shortcut: { key: 'Delete' }, onShortcut: onDelete },
+          { shortcut: { key: 'Delete', shift: true }, onShortcut: onForceDelete },
+          { shortcut: { key: 'D', ctrl: true }, onShortcut: () => deselectAllAssets() },
+          { shortcut: { key: 's' }, onShortcut: () => onStackAssets() },
+          { shortcut: { key: 'a', shift: true }, onShortcut: toggleArchive },
+        );
+      }
+
+      return shortcuts;
+    })(),
+  );
+</script>
+
+<svelte:document onkeydown={onKeyDown} onkeyup={onKeyUp} onselectstart={onSelectStart} use:shortcuts={shortcutList} />
+
+{#if isShowDeleteConfirmation}
+  <DeleteAssetDialog
+    size={idsSelectedAssets.length}
+    onCancel={() => (isShowDeleteConfirmation = false)}
+    onConfirm={() => handlePromiseError(trashOrDelete(true))}
+  />
+{/if}
+
+{#if isShowSelectDate}
+  <ChangeDate
+    withDuration={false}
+    title="Navigate to Time"
+    initialDate={DateTime.now()}
+    timezoneInput={false}
+    onConfirm={async (dateString: AbsoluteResult | RelativeResult) => {
+      isShowSelectDate = false;
+      if (dateString.mode == 'absolute') {
+        const asset = await timelineManager.getClosestAssetToDate(
+          (DateTime.fromISO(dateString.date) as DateTime<true>).toObject(),
+        );
+        if (asset) {
+          setFocusAsset(asset);
+        }
+      }
+    }}
+    onCancel={() => (isShowSelectDate = false)}
+  />
+{/if}
--- a/web/src/lib/managers/photostream-manager/PhotostreamManager.svelte.ts
+++ b/web/src/lib/managers/photostream-manager/PhotostreamManager.svelte.ts
@@ -0,0 +1,423 @@
+import { updateIntersectionMonthGroup } from '$lib/managers/timeline-manager/internal/intersection-support.svelte';
+import { updateGeometry } from '$lib/managers/timeline-manager/internal/layout-support.svelte';
+import { CancellableTask } from '$lib/utils/cancellable-task';
+import { clamp, debounce } from 'lodash-es';
+
+import {
+  PhotostreamSegment,
+  type SegmentIdentifier,
+} from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
+
+import { updateObject } from '$lib/managers/timeline-manager/internal/utils.svelte';
+import type {
+  AssetDescriptor,
+  AssetOperation,
+  MoveAsset,
+  TimelineAsset,
+  TimelineManagerLayoutOptions,
+  Viewport,
+} from '$lib/managers/timeline-manager/types';
+import { setDifference } from '$lib/utils/timeline-util';
+
+export abstract class PhotostreamManager {
+  isInitialized = $state(false);
+  topSectionHeight = $state(0);
+  bottomSectionHeight = $state(60);
+  abstract get months(): PhotostreamSegment[];
+  timelineHeight = $derived.by(
+    () => this.months.reduce((accumulator, b) => accumulator + b.height, 0) + this.topSectionHeight,
+  );
+  assetCount = $derived.by(() => this.months.reduce((accumulator, b) => accumulator + b.assetsCount, 0));
+
+  topIntersectingMonthGroup: PhotostreamSegment | undefined = $state();
+
+  visibleWindow = $derived.by(() => ({
+    top: this.#scrollTop,
+    bottom: this.#scrollTop + this.viewportHeight,
+  }));
+
+  protected initTask = new CancellableTask(
+    () => (this.isInitialized = true),
+    () => (this.isInitialized = false),
+    () => void 0,
+  );
+
+  #viewportHeight = $state(0);
+  #viewportWidth = $state(0);
+  #scrollTop = $state(0);
+
+  #rowHeight = $state(235);
+  #headerHeight = $state(48);
+  #gap = $state(12);
+
+  #scrolling = $state(false);
+  #suspendTransitions = $state(false);
+  #resetScrolling = debounce(() => (this.#scrolling = false), 1000);
+  #resetSuspendTransitions = debounce(() => (this.suspendTransitions = false), 1000);
+  scrollCompensation: {
+    heightDelta: number | undefined;
+    scrollTop: number | undefined;
+    monthGroup: PhotostreamSegment | undefined;
+  } = $state({
+    heightDelta: 0,
+    scrollTop: 0,
+    monthGroup: undefined,
+  });
+
+  constructor() {}
+
+  setLayoutOptions({ headerHeight = 48, rowHeight = 235, gap = 12 }: TimelineManagerLayoutOptions) {
+    let changed = false;
+    changed ||= this.#setHeaderHeight(headerHeight);
+    changed ||= this.#setGap(gap);
+    changed ||= this.#setRowHeight(rowHeight);
+    if (changed) {
+      this.refreshLayout();
+    }
+  }
+
+  #setHeaderHeight(value: number) {
+    if (this.#headerHeight == value) {
+      return false;
+    }
+    this.#headerHeight = value;
+    return true;
+  }
+
+  get headerHeight() {
+    return this.#headerHeight;
+  }
+
+  #setGap(value: number) {
+    if (this.#gap == value) {
+      return false;
+    }
+    this.#gap = value;
+    return true;
+  }
+
+  get gap() {
+    return this.#gap;
+  }
+
+  #setRowHeight(value: number) {
+    if (this.#rowHeight == value) {
+      return false;
+    }
+    this.#rowHeight = value;
+    return true;
+  }
+
+  get rowHeight() {
+    return this.#rowHeight;
+  }
+
+  set scrolling(value: boolean) {
+    this.#scrolling = value;
+    if (value) {
+      this.suspendTransitions = true;
+      this.#resetScrolling();
+    }
+  }
+
+  get scrolling() {
+    return this.#scrolling;
+  }
+
+  set suspendTransitions(value: boolean) {
+    this.#suspendTransitions = value;
+    if (value) {
+      this.#resetSuspendTransitions();
+    }
+  }
+
+  get suspendTransitions() {
+    return this.#suspendTransitions;
+  }
+
+  set viewportWidth(value: number) {
+    const changed = value !== this.#viewportWidth;
+    this.#viewportWidth = value;
+    this.suspendTransitions = true;
+    void this.updateViewportGeometry(changed);
+  }
+
+  get viewportWidth() {
+    return this.#viewportWidth;
+  }
+
+  set viewportHeight(value: number) {
+    this.#viewportHeight = value;
+    this.#suspendTransitions = true;
+    void this.updateViewportGeometry(false);
+  }
+
+  get viewportHeight() {
+    return this.#viewportHeight;
+  }
+
+  updateSlidingWindow(scrollTop: number) {
+    if (this.#scrollTop !== scrollTop) {
+      this.#scrollTop = scrollTop;
+      this.updateIntersections();
+    }
+  }
+
+  clearScrollCompensation() {
+    this.scrollCompensation = {
+      heightDelta: undefined,
+      scrollTop: undefined,
+      monthGroup: undefined,
+    };
+  }
+
+  updateIntersections() {
+    if (!this.isInitialized || this.visibleWindow.bottom === this.visibleWindow.top) {
+      return;
+    }
+    let topIntersectingMonthGroup = undefined;
+    for (const month of this.months) {
+      updateIntersectionMonthGroup(this, month);
+      if (!topIntersectingMonthGroup && month.actuallyIntersecting) {
+        topIntersectingMonthGroup = month;
+      }
+    }
+    if (topIntersectingMonthGroup !== undefined && this.topIntersectingMonthGroup !== topIntersectingMonthGroup) {
+      this.topIntersectingMonthGroup = topIntersectingMonthGroup;
+    }
+    for (const month of this.months) {
+      if (month === this.topIntersectingMonthGroup) {
+        this.topIntersectingMonthGroup.percent = clamp(
+          (this.visibleWindow.top - this.topIntersectingMonthGroup.top) / this.topIntersectingMonthGroup.height,
+          0,
+          1,
+        );
+      } else {
+        month.percent = 0;
+      }
+    }
+  }
+
+  async init() {
+    this.isInitialized = false;
+    await this.initTask.execute(() => Promise.resolve(undefined), true);
+  }
+
+  public destroy() {
+    this.isInitialized = false;
+  }
+
+  async updateViewport(viewport: Viewport) {
+    if (viewport.height === 0 && viewport.width === 0) {
+      return;
+    }
+
+    if (this.viewportHeight === viewport.height && this.viewportWidth === viewport.width) {
+      return;
+    }
+
+    if (!this.initTask.executed) {
+      await (this.initTask.loading ? this.initTask.waitUntilCompletion() : this.init());
+    }
+
+    const changedWidth = viewport.width !== this.viewportWidth;
+    this.viewportHeight = viewport.height;
+    this.viewportWidth = viewport.width;
+    this.updateViewportGeometry(changedWidth);
+  }
+
+  protected updateViewportGeometry(changedWidth: boolean) {
+    if (!this.isInitialized) {
+      return;
+    }
+    if (this.viewportWidth === 0 || this.viewportHeight === 0) {
+      return;
+    }
+    for (const month of this.months) {
+      updateGeometry(this, month, { invalidateHeight: changedWidth });
+    }
+    this.updateIntersections();
+  }
+
+  createLayoutOptions() {
+    const viewportWidth = this.viewportWidth;
+
+    return {
+      spacing: 2,
+      heightTolerance: 0.15,
+      rowHeight: this.#rowHeight,
+      rowWidth: Math.floor(viewportWidth),
+    };
+  }
+
+  async loadSegment(identifier: SegmentIdentifier, options?: { cancelable: boolean }): Promise<void> {
+    let cancelable = true;
+    if (options) {
+      cancelable = options.cancelable;
+    }
+    const segment = this.getSegmentByIdentifier(identifier);
+    if (!segment) {
+      return;
+    }
+
+    if (segment.loader?.executed) {
+      return;
+    }
+
+    const result = await segment.load(cancelable);
+    if (result === 'LOADED') {
+      updateIntersectionMonthGroup(this, segment);
+    }
+  }
+
+  getSegmentByIdentifier(identifier: SegmentIdentifier) {
+    return this.months.find((segment) => identifier.matches(segment));
+  }
+
+  getSegmentForAssetId(assetId: string) {
+    for (const month of this.months) {
+      const asset = month.assets.find((asset) => asset.id === assetId);
+      if (asset) {
+        return month;
+      }
+    }
+  }
+
+  refreshLayout() {
+    for (const month of this.months) {
+      updateGeometry(this, month, { invalidateHeight: true });
+    }
+    this.updateIntersections();
+  }
+
+  getMaxScrollPercent() {
+    const totalHeight = this.timelineHeight + this.bottomSectionHeight + this.topSectionHeight;
+    return (totalHeight - this.viewportHeight) / totalHeight;
+  }
+
+  getMaxScroll() {
+    return this.topSectionHeight + this.bottomSectionHeight + (this.timelineHeight - this.viewportHeight);
+  }
+
+  retrieveRange(start: AssetDescriptor, end: AssetDescriptor): Promise<TimelineAsset[]> {
+    const range: TimelineAsset[] = [];
+    let collecting = false;
+
+    for (const month of this.months) {
+      for (const asset of month.assets) {
+        if (asset.id === start.id) {
+          collecting = true;
+        }
+        if (collecting) {
+          range.push(asset);
+        }
+        if (asset.id === end.id) {
+          return Promise.resolve(range);
+        }
+      }
+    }
+    return Promise.resolve(range);
+  }
+
+  updateAssetOperation(ids: string[], operation: AssetOperation) {
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    return this.#runAssetOperation(new Set(ids), operation);
+  }
+
+  upsertAssets(assets: TimelineAsset[]) {
+    const notExcluded = assets.filter((asset) => !this.isExcluded(asset));
+    const notUpdated = this.#updateAssets(notExcluded);
+    this.addAssetsToSegments([...notUpdated]);
+  }
+
+  #updateAssets(assets: TimelineAsset[]) {
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const lookup = new Map<string, TimelineAsset>(assets.map((asset) => [asset.id, asset]));
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const { unprocessedIds } = this.#runAssetOperation(new Set(lookup.keys()), (asset) =>
+      updateObject(asset, lookup.get(asset.id)),
+    );
+    const result: TimelineAsset[] = [];
+    for (const id of unprocessedIds.values()) {
+      result.push(lookup.get(id)!);
+    }
+    return result;
+  }
+
+  removeAssets(ids: string[]) {
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const { unprocessedIds } = this.#runAssetOperation(new Set(ids), () => ({ remove: true }));
+    return [...unprocessedIds];
+  }
+
+  isExcluded(_: TimelineAsset) {
+    return false;
+  }
+
+  protected createUpsertContext(): unknown {
+    return;
+  }
+
+  protected abstract upsertAssetIntoSegment(asset: TimelineAsset, context: unknown): void;
+
+  protected postCreateSegments(): void {}
+
+  protected postUpsert(_: unknown): void {}
+
+  protected addAssetsToSegments(assets: TimelineAsset[]) {
+    if (assets.length === 0) {
+      return;
+    }
+    const context = this.createUpsertContext();
+    const monthCount = this.months.length;
+    for (const asset of assets) {
+      this.upsertAssetIntoSegment(asset, context);
+    }
+    if (this.months.length !== monthCount) {
+      this.postCreateSegments();
+    }
+    this.postUpsert(context);
+    this.updateIntersections();
+  }
+
+  #runAssetOperation(ids: Set<string>, operation: AssetOperation) {
+    if (ids.size === 0) {
+      // eslint-disable-next-line svelte/prefer-svelte-reactivity
+      return { processedIds: new Set(), unprocessedIds: ids, changedGeometry: false };
+    }
+
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const changedMonthGroups = new Set<PhotostreamSegment>();
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    let idsToProcess = new Set(ids);
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const idsProcessed = new Set<string>();
+    const combinedMoveAssets: MoveAsset[][] = [];
+    for (const month of this.months) {
+      if (idsToProcess.size > 0) {
+        const { moveAssets, processedIds, changedGeometry } = month.runAssetOperation(idsToProcess, operation);
+        if (moveAssets.length > 0) {
+          combinedMoveAssets.push(moveAssets);
+        }
+        idsToProcess = setDifference(idsToProcess, processedIds);
+        for (const id of processedIds) {
+          idsProcessed.add(id);
+        }
+        if (changedGeometry) {
+          changedMonthGroups.add(month);
+        }
+      }
+    }
+    if (combinedMoveAssets.length > 0) {
+      this.addAssetsToSegments(combinedMoveAssets.flat().map((a) => a.asset));
+    }
+    const changedGeometry = changedMonthGroups.size > 0;
+    for (const month of changedMonthGroups) {
+      updateGeometry(this, month, { invalidateHeight: true });
+    }
+    if (changedGeometry) {
+      this.updateIntersections();
+    }
+    return { unprocessedIds: idsToProcess, processedIds: idsProcessed, changedGeometry };
+  }
+}
--- a/web/src/lib/managers/photostream-manager/PhotostreamSegment.svelte.ts
+++ b/web/src/lib/managers/photostream-manager/PhotostreamSegment.svelte.ts
@@ -0,0 +1,195 @@
+import { CancellableTask } from '$lib/utils/cancellable-task';
+import { handleError } from '$lib/utils/handle-error';
+import { t } from 'svelte-i18n';
+import { get } from 'svelte/store';
+
+import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+import type { AssetOperation, MoveAsset, TimelineAsset } from '$lib/managers/timeline-manager/types';
+import type { ViewerAsset } from '$lib/managers/timeline-manager/viewer-asset.svelte';
+
+export type SegmentIdentifier = {
+  matches(segment: PhotostreamSegment): boolean;
+};
+export abstract class PhotostreamSegment {
+  #intersecting = $state(false);
+  actuallyIntersecting = $state(false);
+  #isLoaded = $state(false);
+
+  #height = $state(0);
+  #top = $state(0);
+  #assets = $derived.by(() => this.viewerAssets.map((viewerAsset) => viewerAsset.asset));
+
+  initialCount = $state(0);
+  percent = $state(0);
+
+  assetsCount = $derived.by(() => (this.isLoaded ? this.viewerAssets.length : this.initialCount));
+  loader = new CancellableTask(
+    () => this.markLoaded(),
+    () => this.markCanceled,
+    () => this.handleLoadError,
+  );
+  isHeightActual = $state(false);
+
+  abstract get timelineManager(): PhotostreamManager;
+
+  abstract get identifier(): SegmentIdentifier;
+
+  abstract get id(): string;
+
+  get isLoaded() {
+    return this.#isLoaded;
+  }
+
+  protected markLoaded() {
+    this.#isLoaded = true;
+  }
+
+  protected markCanceled() {
+    this.#isLoaded = false;
+  }
+
+  set intersecting(newValue: boolean) {
+    const old = this.#intersecting;
+    if (old === newValue) {
+      return;
+    }
+    this.#intersecting = newValue;
+    if (newValue) {
+      void this.load(true);
+    } else {
+      this.cancel();
+    }
+  }
+
+  get intersecting() {
+    return this.#intersecting;
+  }
+
+  async load(cancelable: boolean): Promise<'DONE' | 'WAITED' | 'CANCELED' | 'LOADED' | 'ERRORED'> {
+    return await this.loader?.execute(async (signal: AbortSignal) => {
+      await this.fetch(signal);
+    }, cancelable);
+  }
+
+  protected abstract fetch(signal: AbortSignal): Promise<void>;
+
+  get assets(): TimelineAsset[] {
+    return this.#assets;
+  }
+
+  abstract get viewerAssets(): ViewerAsset[];
+
+  set height(height: number) {
+    if (this.#height === height) {
+      return;
+    }
+    const { timelineManager: store, percent } = this;
+    const index = store.months.indexOf(this);
+    const heightDelta = height - this.#height;
+    this.#height = height;
+    const prevMonthGroup = store.months[index - 1];
+    if (prevMonthGroup) {
+      const newTop = prevMonthGroup.#top + prevMonthGroup.#height;
+      if (this.#top !== newTop) {
+        this.#top = newTop;
+      }
+    }
+    for (let cursor = index + 1; cursor < store.months.length; cursor++) {
+      const monthGroup = this.timelineManager.months[cursor];
+      const newTop = monthGroup.#top + heightDelta;
+      if (monthGroup.#top !== newTop) {
+        monthGroup.#top = newTop;
+      }
+    }
+    if (store.topIntersectingMonthGroup) {
+      const currentIndex = store.months.indexOf(store.topIntersectingMonthGroup);
+      if (currentIndex > 0) {
+        if (index < currentIndex) {
+          store.scrollCompensation = {
+            heightDelta,
+            scrollTop: undefined,
+            monthGroup: this,
+          };
+        } else if (percent > 0) {
+          const top = this.top + height * percent;
+          store.scrollCompensation = {
+            heightDelta: undefined,
+            scrollTop: top,
+            monthGroup: this,
+          };
+        }
+      }
+    }
+  }
+
+  get height() {
+    return this.#height;
+  }
+
+  get top(): number {
+    return this.#top + this.timelineManager.topSectionHeight;
+  }
+
+  protected handleLoadError(error: unknown) {
+    const _$t = get(t);
+    handleError(error, _$t('errors.failed_to_load_assets'));
+  }
+
+  cancel() {
+    this.loader?.cancel();
+  }
+
+  layout(_: boolean) {}
+
+  updateIntersection({ intersecting, actuallyIntersecting }: { intersecting: boolean; actuallyIntersecting: boolean }) {
+    this.intersecting = intersecting;
+    this.actuallyIntersecting = actuallyIntersecting;
+  }
+
+  abstract findAssetAbsolutePosition(assetId: string): number;
+
+  runAssetOperation(ids: Set<string>, operation: AssetOperation) {
+    if (ids.size === 0) {
+      return {
+        moveAssets: [] as MoveAsset[],
+        // eslint-disable-next-line svelte/prefer-svelte-reactivity
+        processedIds: new Set<string>(),
+        unprocessedIds: ids,
+        changedGeometry: false,
+      };
+    }
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const unprocessedIds = new Set<string>(ids);
+    // eslint-disable-next-line svelte/prefer-svelte-reactivity
+    const processedIds = new Set<string>();
+    const moveAssets: MoveAsset[] = [];
+    let changedGeometry = false;
+    for (const assetId of unprocessedIds) {
+      const index = this.viewerAssets.findIndex((viewAsset) => viewAsset.id == assetId);
+      if (index === -1) {
+        continue;
+      }
+
+      const asset = this.viewerAssets[index].asset!;
+      const oldTime = { ...asset.localDateTime };
+      const opResult = operation(asset);
+      let remove = false;
+      if (opResult) {
+        remove = (opResult as { remove: boolean }).remove ?? false;
+      }
+      const newTime = asset.localDateTime;
+      if (oldTime.year !== newTime.year || oldTime.month !== newTime.month || oldTime.day !== newTime.day) {
+        const { year, month, day } = newTime;
+        remove = true;
+        moveAssets.push({ asset, date: { year, month, day } });
+      }
+      unprocessedIds.delete(assetId);
+      processedIds.add(assetId);
+      if (remove || this.timelineManager.isExcluded(asset)) {
+        this.viewerAssets.splice(index, 1);
+        changedGeometry = true;
+      }
+    }
+    return { moveAssets, processedIds, unprocessedIds, changedGeometry };
+  }
+}
--- a/web/src/lib/managers/timeline-manager/day-group.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/day-group.svelte.ts
@@ -13,6 +13,7 @@ export class DayGroup {
  readonly monthGroup: MonthGroup;
  readonly index: number;
  readonly groupTitle: string;
+  readonly groupTitleFull: string;
  readonly day: number;
  viewerAssets: ViewerAsset[] = $state([]);

@@ -26,11 +27,12 @@ export class DayGroup {
  #col = $state(0);
  #deferredLayout = false;

-  constructor(monthGroup: MonthGroup, index: number, day: number, groupTitle: string) {
+  constructor(monthGroup: MonthGroup, index: number, day: number, groupTitle: string, groupTitleFull: string) {
    this.index = index;
    this.monthGroup = monthGroup;
    this.day = day;
    this.groupTitle = groupTitle;
+    this.groupTitleFull = groupTitleFull;
  }

  get top() {
@@ -127,7 +129,11 @@ export class DayGroup {

      const asset = this.viewerAssets[index].asset!;
      const oldTime = { ...asset.localDateTime };
-      let { remove } = operation(asset);
+      const opResult = operation(asset);
+      let remove = false;
+      if (opResult) {
+        remove = (opResult as { remove: boolean }).remove ?? false;
+      }
      const newTime = asset.localDateTime;
      if (oldTime.year !== newTime.year || oldTime.month !== newTime.month || oldTime.day !== newTime.day) {
        const { year, month, day } = newTime;
--- a/web/src/lib/managers/timeline-manager/internal/intersection-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/intersection-support.svelte.ts
@@ -1,27 +1,23 @@
+import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+import type { PhotostreamSegment } from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
 import { TUNABLES } from '$lib/utils/tunables';
-import type { MonthGroup } from '../month-group.svelte';
-import type { TimelineManager } from '../timeline-manager.svelte';

 const {
  TIMELINE: { INTERSECTION_EXPAND_TOP, INTERSECTION_EXPAND_BOTTOM },
 } = TUNABLES;

-export function updateIntersectionMonthGroup(timelineManager: TimelineManager, month: MonthGroup) {
-  const actuallyIntersecting = calculateMonthGroupIntersecting(timelineManager, month, 0, 0);
+export function updateIntersectionMonthGroup(timelineManager: PhotostreamManager, month: PhotostreamSegment) {
+  const actuallyIntersecting = calculateSegmentIntersecting(timelineManager, month, 0, 0);
  let preIntersecting = false;
  if (!actuallyIntersecting) {
-    preIntersecting = calculateMonthGroupIntersecting(
+    preIntersecting = calculateSegmentIntersecting(
      timelineManager,
      month,
      INTERSECTION_EXPAND_TOP,
      INTERSECTION_EXPAND_BOTTOM,
    );
  }
-  month.intersecting = actuallyIntersecting || preIntersecting;
-  month.actuallyIntersecting = actuallyIntersecting;
-  if (preIntersecting || actuallyIntersecting) {
-    timelineManager.clearDeferredLayout(month);
-  }
+  month.updateIntersection({ intersecting: actuallyIntersecting || preIntersecting, actuallyIntersecting });
 }

 /**
@@ -40,9 +36,9 @@ export function isIntersecting(regionTop: number, regionBottom: number, windowTo
  );
 }

-export function calculateMonthGroupIntersecting(
-  timelineManager: TimelineManager,
-  monthGroup: MonthGroup,
+export function calculateSegmentIntersecting(
+  timelineManager: PhotostreamManager,
+  monthGroup: PhotostreamSegment,
  expandTop: number,
  expandBottom: number,
 ) {
@@ -58,7 +54,7 @@ export function calculateMonthGroupIntersecting(
 * Calculate intersection for viewer assets with additional parameters like header height and scroll compensation
 */
 export function calculateViewerAssetIntersecting(
-  timelineManager: TimelineManager,
+  timelineManager: PhotostreamManager,
  positionTop: number,
  positionHeight: number,
  expandTop: number = INTERSECTION_EXPAND_TOP,
--- a/web/src/lib/managers/timeline-manager/internal/layout-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/layout-support.svelte.ts
@@ -1,8 +1,14 @@
+import type { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+import type { PhotostreamSegment } from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
+import type { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
 import type { MonthGroup } from '../month-group.svelte';
-import type { TimelineManager } from '../timeline-manager.svelte';
 import type { UpdateGeometryOptions } from '../types';

-export function updateGeometry(timelineManager: TimelineManager, month: MonthGroup, options: UpdateGeometryOptions) {
+export function updateGeometry(
+  timelineManager: PhotostreamManager,
+  month: PhotostreamSegment,
+  options: UpdateGeometryOptions,
+) {
  const { invalidateHeight, noDefer = false } = options;
  if (invalidateHeight) {
    month.isHeightActual = false;
@@ -17,7 +23,7 @@ export function updateGeometry(timelineManager: TimelineManager, month: MonthGro
    }
    return;
  }
-  layoutMonthGroup(timelineManager, month, noDefer);
+  month.layout(noDefer);
 }

 export function layoutMonthGroup(timelineManager: TimelineManager, month: MonthGroup, noDefer: boolean = false) {
--- a/web/src/lib/managers/timeline-manager/internal/operations-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/operations-support.svelte.ts
@@ -1,104 +0,0 @@
-import { setDifference, type TimelineDate } from '$lib/utils/timeline-util';
-import { AssetOrder } from '@immich/sdk';
-
-import { SvelteSet } from 'svelte/reactivity';
-import { GroupInsertionCache } from '../group-insertion-cache.svelte';
-import { MonthGroup } from '../month-group.svelte';
-import type { TimelineManager } from '../timeline-manager.svelte';
-import type { AssetOperation, TimelineAsset } from '../types';
-import { updateGeometry } from './layout-support.svelte';
-import { getMonthGroupByDate } from './search-support.svelte';
-
-export function addAssetsToMonthGroups(
-  timelineManager: TimelineManager,
-  assets: TimelineAsset[],
-  options: { order: AssetOrder },
-) {
-  if (assets.length === 0) {
-    return;
-  }
-
-  const addContext = new GroupInsertionCache();
-  const updatedMonthGroups = new SvelteSet<MonthGroup>();
-  const monthCount = timelineManager.months.length;
-  for (const asset of assets) {
-    let month = getMonthGroupByDate(timelineManager, asset.localDateTime);
-
-    if (!month) {
-      month = new MonthGroup(timelineManager, asset.localDateTime, 1, options.order);
-      month.isLoaded = true;
-      timelineManager.months.push(month);
-    }
-
-    month.addTimelineAsset(asset, addContext);
-    updatedMonthGroups.add(month);
-  }
-
-  if (timelineManager.months.length !== monthCount) {
-    timelineManager.months.sort((a, b) => {
-      return a.yearMonth.year === b.yearMonth.year
-        ? b.yearMonth.month - a.yearMonth.month
-        : b.yearMonth.year - a.yearMonth.year;
-    });
-  }
-
-  for (const group of addContext.existingDayGroups) {
-    group.sortAssets(options.order);
-  }
-
-  for (const monthGroup of addContext.bucketsWithNewDayGroups) {
-    monthGroup.sortDayGroups();
-  }
-
-  for (const month of addContext.updatedBuckets) {
-    month.sortDayGroups();
-    updateGeometry(timelineManager, month, { invalidateHeight: true });
-  }
-  timelineManager.updateIntersections();
-}
-
-export function runAssetOperation(
-  timelineManager: TimelineManager,
-  ids: Set<string>,
-  operation: AssetOperation,
-  options: { order: AssetOrder },
-) {
-  if (ids.size === 0) {
-    return { processedIds: new SvelteSet(), unprocessedIds: ids, changedGeometry: false };
-  }
-
-  const changedMonthGroups = new SvelteSet<MonthGroup>();
-  let idsToProcess = new SvelteSet(ids);
-  const idsProcessed = new SvelteSet<string>();
-  const combinedMoveAssets: { asset: TimelineAsset; date: TimelineDate }[][] = [];
-  for (const month of timelineManager.months) {
-    if (idsToProcess.size > 0) {
-      const { moveAssets, processedIds, changedGeometry } = month.runAssetOperation(idsToProcess, operation);
-      if (moveAssets.length > 0) {
-        combinedMoveAssets.push(moveAssets);
-      }
-      idsToProcess = setDifference(idsToProcess, processedIds);
-      for (const id of processedIds) {
-        idsProcessed.add(id);
-      }
-      if (changedGeometry) {
-        changedMonthGroups.add(month);
-      }
-    }
-  }
-  if (combinedMoveAssets.length > 0) {
-    addAssetsToMonthGroups(
-      timelineManager,
-      combinedMoveAssets.flat().map((a) => a.asset),
-      options,
-    );
-  }
-  const changedGeometry = changedMonthGroups.size > 0;
-  for (const month of changedMonthGroups) {
-    updateGeometry(timelineManager, month, { invalidateHeight: true });
-  }
-  if (changedGeometry) {
-    timelineManager.updateIntersections();
-  }
-  return { unprocessedIds: idsToProcess, processedIds: idsProcessed, changedGeometry };
-}
--- a/web/src/lib/managers/timeline-manager/internal/websocket-support.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/internal/websocket-support.svelte.ts
@@ -13,10 +13,10 @@ export class WebsocketSupport {
  #processPendingChanges = throttle(() => {
    const { add, update, remove } = this.#getPendingChangeBatches();
    if (add.length > 0) {
-      this.#timelineManager.addAssets(add);
+      this.#timelineManager.upsertAssets(add);
    }
    if (update.length > 0) {
-      this.#timelineManager.updateAssets(update);
+      this.#timelineManager.upsertAssets(update);
    }
    if (remove.length > 0) {
      this.#timelineManager.removeAssets(remove);
--- a/web/src/lib/managers/timeline-manager/month-group.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/month-group.svelte.ts
@@ -1,22 +1,26 @@
 import { AssetOrder, type TimeBucketAssetResponseDto } from '@immich/sdk';

-import { CancellableTask } from '$lib/utils/cancellable-task';
-import { handleError } from '$lib/utils/handle-error';
 import {
  formatGroupTitle,
+  formatGroupTitleFull,
  formatMonthGroupTitle,
  fromTimelinePlainDate,
  fromTimelinePlainDateTime,
  fromTimelinePlainYearMonth,
+  getSegmentIdentifier,
  getTimes,
  setDifference,
  type TimelineDateTime,
  type TimelineYearMonth,
 } from '$lib/utils/timeline-util';

-import { t } from 'svelte-i18n';
-import { get } from 'svelte/store';
+import { layoutMonthGroup, updateGeometry } from '$lib/managers/timeline-manager/internal/layout-support.svelte';
+import { loadFromTimeBuckets } from '$lib/managers/timeline-manager/internal/load-support.svelte';

+import {
+  PhotostreamSegment,
+  type SegmentIdentifier,
+} from '$lib/managers/photostream-manager/PhotostreamSegment.svelte';
 import { SvelteSet } from 'svelte/reactivity';
 import { DayGroup } from './day-group.svelte';
 import { GroupInsertionCache } from './group-insertion-cache.svelte';
@@ -24,71 +28,49 @@ import type { TimelineManager } from './timeline-manager.svelte';
 import type { AssetDescriptor, AssetOperation, Direction, MoveAsset, TimelineAsset } from './types';
 import { ViewerAsset } from './viewer-asset.svelte';

-export class MonthGroup {
-  #intersecting: boolean = $state(false);
-  actuallyIntersecting: boolean = $state(false);
-  isLoaded: boolean = $state(false);
+export class MonthGroup extends PhotostreamSegment {
  dayGroups: DayGroup[] = $state([]);
-  readonly timelineManager: TimelineManager;

-  #height: number = $state(0);
-  #top: number = $state(0);
-
-  #initialCount: number = 0;
  #sortOrder: AssetOrder = AssetOrder.Desc;
-  percent: number = $state(0);
-
-  assetsCount: number = $derived(
-    this.isLoaded
-      ? this.dayGroups.reduce((accumulator, g) => accumulator + g.viewerAssets.length, 0)
-      : this.#initialCount,
-  );
-  loader: CancellableTask | undefined;
-  isHeightActual: boolean = $state(false);
+  #yearMonth: TimelineYearMonth;
+  #identifier: SegmentIdentifier;
+  #timelineManager: TimelineManager;

  readonly monthGroupTitle: string;
-  readonly yearMonth: TimelineYearMonth;

  constructor(
-    store: TimelineManager,
+    timelineManager: TimelineManager,
    yearMonth: TimelineYearMonth,
    initialCount: number,
+    loaded: boolean,
    order: AssetOrder = AssetOrder.Desc,
  ) {
-    this.timelineManager = store;
-    this.#initialCount = initialCount;
+    super();
+    this.initialCount = initialCount;
+    this.#yearMonth = yearMonth;
+    this.#identifier = getSegmentIdentifier(yearMonth);
+    this.#timelineManager = timelineManager;
    this.#sortOrder = order;
-
-    this.yearMonth = yearMonth;
    this.monthGroupTitle = formatMonthGroupTitle(fromTimelinePlainYearMonth(yearMonth));
-
-    this.loader = new CancellableTask(
-      () => {
-        this.isLoaded = true;
-      },
-      () => {
-        this.dayGroups = [];
-        this.isLoaded = false;
-      },
-      this.#handleLoadError,
-    );
-  }
-
-  set intersecting(newValue: boolean) {
-    const old = this.#intersecting;
-    if (old === newValue) {
-      return;
-    }
-    this.#intersecting = newValue;
-    if (newValue) {
-      void this.timelineManager.loadMonthGroup(this.yearMonth);
-    } else {
-      this.cancel();
+    if (loaded) {
+      this.markLoaded();
    }
  }

-  get intersecting() {
-    return this.#intersecting;
+  get identifier() {
+    return this.#identifier;
+  }
+
+  get timelineManager() {
+    return this.#timelineManager;
+  }
+
+  get yearMonth() {
+    return this.#yearMonth;
+  }
+
+  fetch(signal: AbortSignal): Promise<void> {
+    return loadFromTimeBuckets(this.timelineManager, this, this.timelineManager.options, signal);
  }

  get lastDayGroup() {
@@ -99,9 +81,9 @@ export class MonthGroup {
    return this.dayGroups[0]?.getFirstAsset();
  }

-  getAssets() {
+  get viewerAssets() {
    // eslint-disable-next-line unicorn/no-array-reduce
-    return this.dayGroups.reduce((accumulator: TimelineAsset[], g: DayGroup) => accumulator.concat(g.getAssets()), []);
+    return this.dayGroups.reduce((accumulator: ViewerAsset[], g: DayGroup) => accumulator.concat(g.viewerAssets), []);
  }

  sortDayGroups() {
@@ -222,7 +204,8 @@ export class MonthGroup {
      addContext.setDayGroup(dayGroup, localDateTime);
    } else {
      const groupTitle = formatGroupTitle(fromTimelinePlainDate(localDateTime));
-      dayGroup = new DayGroup(this, this.dayGroups.length, localDateTime.day, groupTitle);
+      const groupTitleFull = formatGroupTitleFull(fromTimelinePlainDate(localDateTime));
+      dayGroup = new DayGroup(this, this.dayGroups.length, localDateTime.day, groupTitle, groupTitleFull);
      this.dayGroups.push(dayGroup);
      addContext.setDayGroup(dayGroup, localDateTime);
      addContext.newDayGroups.add(dayGroup);
@@ -242,67 +225,15 @@ export class MonthGroup {
    return this.getRandomDayGroup()?.getRandomAsset()?.asset;
  }

+  get id() {
+    return this.viewId;
+  }
+
  get viewId() {
    const { year, month } = this.yearMonth;
    return year + '-' + month;
  }

-  set height(height: number) {
-    if (this.#height === height) {
-      return;
-    }
-    const { timelineManager: store, percent } = this;
-    const index = store.months.indexOf(this);
-    const heightDelta = height - this.#height;
-    this.#height = height;
-    const prevMonthGroup = store.months[index - 1];
-    if (prevMonthGroup) {
-      const newTop = prevMonthGroup.#top + prevMonthGroup.#height;
-      if (this.#top !== newTop) {
-        this.#top = newTop;
-      }
-    }
-    for (let cursor = index + 1; cursor < store.months.length; cursor++) {
-      const monthGroup = this.timelineManager.months[cursor];
-      const newTop = monthGroup.#top + heightDelta;
-      if (monthGroup.#top !== newTop) {
-        monthGroup.#top = newTop;
-      }
-    }
-    if (store.topIntersectingMonthGroup) {
-      const currentIndex = store.months.indexOf(store.topIntersectingMonthGroup);
-      if (currentIndex > 0) {
-        if (index < currentIndex) {
-          store.scrollCompensation = {
-            heightDelta,
-            scrollTop: undefined,
-            monthGroup: this,
-          };
-        } else if (percent > 0) {
-          const top = this.top + height * percent;
-          store.scrollCompensation = {
-            heightDelta: undefined,
-            scrollTop: top,
-            monthGroup: this,
-          };
-        }
-      }
-    }
-  }
-
-  get height() {
-    return this.#height;
-  }
-
-  get top(): number {
-    return this.#top + this.timelineManager.topSectionHeight;
-  }
-
-  #handleLoadError(error: unknown) {
-    const _$t = get(t);
-    handleError(error, _$t('errors.failed_to_load_assets'));
-  }
-
  findDayGroupForAsset(asset: TimelineAsset) {
    for (const group of this.dayGroups) {
      if (group.viewerAssets.some((viewerAsset) => viewerAsset.id === asset.id)) {
@@ -316,7 +247,7 @@ export class MonthGroup {
  }

  findAssetAbsolutePosition(assetId: string) {
-    this.timelineManager.clearDeferredLayout(this);
+    this.#clearDeferredLayout();
    for (const group of this.dayGroups) {
      const viewerAsset = group.viewerAssets.find((viewAsset) => viewAsset.id === assetId);
      if (viewerAsset) {
@@ -374,4 +305,26 @@ export class MonthGroup {
  cancel() {
    this.loader?.cancel();
  }
+
+  layout(noDefer: boolean) {
+    layoutMonthGroup(this.timelineManager, this, noDefer);
+  }
+
+  #clearDeferredLayout() {
+    const hasDeferred = this.dayGroups.some((group) => group.deferredLayout);
+    if (hasDeferred) {
+      updateGeometry(this.timelineManager, this, { invalidateHeight: true, noDefer: true });
+      for (const group of this.dayGroups) {
+        group.deferredLayout = false;
+      }
+    }
+  }
+
+  updateIntersection({ intersecting, actuallyIntersecting }: { intersecting: boolean; actuallyIntersecting: boolean }) {
+    this.intersecting = intersecting;
+    this.actuallyIntersecting = actuallyIntersecting;
+    if (intersecting) {
+      this.#clearDeferredLayout();
+    }
+  }
 }
--- a/web/src/lib/managers/timeline-manager/timeline-manager.svelte.spec.ts
+++ b/web/src/lib/managers/timeline-manager/timeline-manager.svelte.spec.ts
@@ -1,7 +1,7 @@
 import { sdkMock } from '$lib/__mocks__/sdk.mock';
 import { getMonthGroupByDate } from '$lib/managers/timeline-manager/internal/search-support.svelte';
 import { AbortError } from '$lib/utils';
-import { fromISODateTimeUTCToObject } from '$lib/utils/timeline-util';
+import { fromISODateTimeUTCToObject, getSegmentIdentifier } from '$lib/utils/timeline-util';
 import { type AssetResponseDto, type TimeBucketAssetResponseDto } from '@immich/sdk';
 import { timelineAssetFactory, toResponseDto } from '@test-data/factories/asset-factory';
 import { TimelineManager } from './timeline-manager.svelte';
@@ -92,7 +92,7 @@ describe('TimelineManager', () => {
    });
  });

-  describe('loadMonthGroup', () => {
+  describe('loadSegment', () => {
    let timelineManager: TimelineManager;
    const bucketAssets: Record<string, TimelineAsset[]> = {
      '2024-01-03T00:00:00.000Z': timelineAssetFactory.buildList(1).map((asset) =>
@@ -128,52 +128,52 @@ describe('TimelineManager', () => {
    });

    it('loads a month', async () => {
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(0);
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(0);
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
      expect(sdkMock.getTimeBucket).toBeCalledTimes(1);
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(3);
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(3);
    });

    it('ignores invalid months', async () => {
-      await timelineManager.loadMonthGroup({ year: 2023, month: 1 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2023, month: 1 }));
      expect(sdkMock.getTimeBucket).toBeCalledTimes(0);
    });

    it('cancels month loading', async () => {
      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })!;
-      void timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      void timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
      const abortSpy = vi.spyOn(month!.loader!.cancelToken!, 'abort');
      month?.cancel();
      expect(abortSpy).toBeCalledTimes(1);
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(3);
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(3);
    });

    it('prevents loading months multiple times', async () => {
      await Promise.all([
-        timelineManager.loadMonthGroup({ year: 2024, month: 1 }),
-        timelineManager.loadMonthGroup({ year: 2024, month: 1 }),
+        timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 })),
+        timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 })),
      ]);
      expect(sdkMock.getTimeBucket).toBeCalledTimes(1);

-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
      expect(sdkMock.getTimeBucket).toBeCalledTimes(1);
    });

    it('allows loading a canceled month', async () => {
      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })!;
-      const loadPromise = timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      const loadPromise = timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));

      month.cancel();
      await loadPromise;
-      expect(month?.getAssets().length).toEqual(0);
+      expect(month?.assets.length).toEqual(0);

-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
-      expect(month!.getAssets().length).toEqual(3);
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
+      expect(month!.assets.length).toEqual(3);
    });
  });

-  describe('addAssets', () => {
+  describe('upsertAssets', () => {
    let timelineManager: TimelineManager;

    beforeEach(async () => {
@@ -194,11 +194,11 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-20T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([asset]);
+      timelineManager.upsertAssets([asset]);

      expect(timelineManager.months.length).toEqual(1);
      expect(timelineManager.assetCount).toEqual(1);
-      expect(timelineManager.months[0].getAssets().length).toEqual(1);
+      expect(timelineManager.months[0].assets.length).toEqual(1);
      expect(timelineManager.months[0].yearMonth.year).toEqual(2024);
      expect(timelineManager.months[0].yearMonth.month).toEqual(1);
      expect(timelineManager.months[0].getFirstAsset().id).toEqual(asset.id);
@@ -210,12 +210,12 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-20T12:00:00.000Z'),
        })
        .map((asset) => deriveLocalDateTimeFromFileCreatedAt(asset));
-      timelineManager.addAssets([assetOne]);
-      timelineManager.addAssets([assetTwo]);
+      timelineManager.upsertAssets([assetOne]);
+      timelineManager.upsertAssets([assetTwo]);

      expect(timelineManager.months.length).toEqual(1);
      expect(timelineManager.assetCount).toEqual(2);
-      expect(timelineManager.months[0].getAssets().length).toEqual(2);
+      expect(timelineManager.months[0].assets.length).toEqual(2);
      expect(timelineManager.months[0].yearMonth.year).toEqual(2024);
      expect(timelineManager.months[0].yearMonth.month).toEqual(1);
    });
@@ -236,14 +236,14 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-16T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([assetOne, assetTwo, assetThree]);
+      timelineManager.upsertAssets([assetOne, assetTwo, assetThree]);

      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 });
      expect(month).not.toBeNull();
-      expect(month?.getAssets().length).toEqual(3);
-      expect(month?.getAssets()[0].id).toEqual(assetOne.id);
-      expect(month?.getAssets()[1].id).toEqual(assetThree.id);
-      expect(month?.getAssets()[2].id).toEqual(assetTwo.id);
+      expect(month?.assets.length).toEqual(3);
+      expect(month?.assets[0].id).toEqual(assetOne.id);
+      expect(month?.assets[1].id).toEqual(assetThree.id);
+      expect(month?.assets[2].id).toEqual(assetTwo.id);
    });

    it('orders months by descending date', () => {
@@ -262,7 +262,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2023-01-20T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([assetOne, assetTwo, assetThree]);
+      timelineManager.upsertAssets([assetOne, assetTwo, assetThree]);

      expect(timelineManager.months.length).toEqual(3);
      expect(timelineManager.months[0].yearMonth.year).toEqual(2024);
@@ -276,11 +276,11 @@ describe('TimelineManager', () => {
    });

    it('updates existing asset', () => {
-      const updateAssetsSpy = vi.spyOn(timelineManager, 'updateAssets');
+      const updateAssetsSpy = vi.spyOn(timelineManager, 'upsertAssets');
      const asset = deriveLocalDateTimeFromFileCreatedAt(timelineAssetFactory.build());
-      timelineManager.addAssets([asset]);
+      timelineManager.upsertAssets([asset]);

-      timelineManager.addAssets([asset]);
+      timelineManager.upsertAssets([asset]);
      expect(updateAssetsSpy).toBeCalledWith([asset]);
      expect(timelineManager.assetCount).toEqual(1);
    });
@@ -292,7 +292,7 @@ describe('TimelineManager', () => {

      const timelineManager = new TimelineManager();
      await timelineManager.updateOptions({ isTrashed: true });
-      timelineManager.addAssets([asset, trashedAsset]);
+      timelineManager.upsertAssets([asset, trashedAsset]);
      expect(await getAssets(timelineManager)).toEqual([trashedAsset]);
    });
  });
@@ -307,22 +307,15 @@ describe('TimelineManager', () => {
      await timelineManager.updateViewport({ width: 1588, height: 1000 });
    });

-    it('ignores non-existing assets', () => {
-      timelineManager.updateAssets([deriveLocalDateTimeFromFileCreatedAt(timelineAssetFactory.build())]);
-
-      expect(timelineManager.months.length).toEqual(0);
-      expect(timelineManager.assetCount).toEqual(0);
-    });
-
    it('updates an asset', () => {
      const asset = deriveLocalDateTimeFromFileCreatedAt(timelineAssetFactory.build({ isFavorite: false }));
      const updatedAsset = { ...asset, isFavorite: true };

-      timelineManager.addAssets([asset]);
+      timelineManager.upsertAssets([asset]);
      expect(timelineManager.assetCount).toEqual(1);
      expect(timelineManager.months[0].getFirstAsset().isFavorite).toEqual(false);

-      timelineManager.updateAssets([updatedAsset]);
+      timelineManager.upsertAssets([updatedAsset]);
      expect(timelineManager.assetCount).toEqual(1);
      expect(timelineManager.months[0].getFirstAsset().isFavorite).toEqual(true);
    });
@@ -338,17 +331,17 @@ describe('TimelineManager', () => {
        fileCreatedAt: fromISODateTimeUTCToObject('2024-03-20T12:00:00.000Z'),
      });

-      timelineManager.addAssets([asset]);
+      timelineManager.upsertAssets([asset]);
      expect(timelineManager.months.length).toEqual(1);
      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })).not.toBeUndefined();
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(1);
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(1);

-      timelineManager.updateAssets([updatedAsset]);
+      timelineManager.upsertAssets([updatedAsset]);
      expect(timelineManager.months.length).toEqual(2);
      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })).not.toBeUndefined();
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.getAssets().length).toEqual(0);
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 1 })?.assets.length).toEqual(0);
      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 3 })).not.toBeUndefined();
-      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 3 })?.getAssets().length).toEqual(1);
+      expect(getMonthGroupByDate(timelineManager, { year: 2024, month: 3 })?.assets.length).toEqual(1);
    });
  });

@@ -363,7 +356,7 @@ describe('TimelineManager', () => {
    });

    it('ignores invalid IDs', () => {
-      timelineManager.addAssets(
+      timelineManager.upsertAssets(
        timelineAssetFactory
          .buildList(2, {
            fileCreatedAt: fromISODateTimeUTCToObject('2024-01-20T12:00:00.000Z'),
@@ -374,7 +367,7 @@ describe('TimelineManager', () => {

      expect(timelineManager.assetCount).toEqual(2);
      expect(timelineManager.months.length).toEqual(1);
-      expect(timelineManager.months[0].getAssets().length).toEqual(2);
+      expect(timelineManager.months[0].assets.length).toEqual(2);
    });

    it('removes asset from month', () => {
@@ -383,12 +376,12 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-20T12:00:00.000Z'),
        })
        .map((asset) => deriveLocalDateTimeFromFileCreatedAt(asset));
-      timelineManager.addAssets([assetOne, assetTwo]);
+      timelineManager.upsertAssets([assetOne, assetTwo]);
      timelineManager.removeAssets([assetOne.id]);

      expect(timelineManager.assetCount).toEqual(1);
      expect(timelineManager.months.length).toEqual(1);
-      expect(timelineManager.months[0].getAssets().length).toEqual(1);
+      expect(timelineManager.months[0].assets.length).toEqual(1);
    });

    it('does not remove month when empty', () => {
@@ -397,7 +390,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-20T12:00:00.000Z'),
        })
        .map((asset) => deriveLocalDateTimeFromFileCreatedAt(asset));
-      timelineManager.addAssets(assets);
+      timelineManager.upsertAssets(assets);
      timelineManager.removeAssets(assets.map((asset) => asset.id));

      expect(timelineManager.assetCount).toEqual(0);
@@ -429,7 +422,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-01-15T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([assetOne, assetTwo]);
+      timelineManager.upsertAssets([assetOne, assetTwo]);
      expect(timelineManager.getFirstAsset()).toEqual(assetOne);
    });
  });
@@ -477,45 +470,45 @@ describe('TimelineManager', () => {
    });

    it('returns previous assetId', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 1 });

-      const a = month!.getAssets()[0];
-      const b = month!.getAssets()[1];
+      const a = month!.assets[0];
+      const b = month!.assets[1];
      const previous = await timelineManager.getLaterAsset(b);
      expect(previous).toEqual(a);
    });

    it('returns previous assetId spanning multiple months', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 2 });
-      await timelineManager.loadMonthGroup({ year: 2024, month: 3 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 2 }));
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 3 }));

      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 2 });
      const previousMonth = getMonthGroupByDate(timelineManager, { year: 2024, month: 3 });
-      const a = month!.getAssets()[0];
-      const b = previousMonth!.getAssets()[0];
+      const a = month!.assets[0];
+      const b = previousMonth!.assets[0];
      const previous = await timelineManager.getLaterAsset(a);
      expect(previous).toEqual(b);
    });

    it('loads previous month', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 2 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 2 }));
      const month = getMonthGroupByDate(timelineManager, { year: 2024, month: 2 });
      const previousMonth = getMonthGroupByDate(timelineManager, { year: 2024, month: 3 });
      const a = month!.getFirstAsset();
      const b = previousMonth!.getFirstAsset();
-      const loadMonthGroupSpy = vi.spyOn(month!.loader!, 'execute');
+      const loadSegmentSpy = vi.spyOn(month!.loader!, 'execute');
      const previousMonthSpy = vi.spyOn(previousMonth!.loader!, 'execute');
      const previous = await timelineManager.getLaterAsset(a);
      expect(previous).toEqual(b);
-      expect(loadMonthGroupSpy).toBeCalledTimes(0);
+      expect(loadSegmentSpy).toBeCalledTimes(0);
      expect(previousMonthSpy).toBeCalledTimes(0);
    });

    it('skips removed assets', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 1 });
-      await timelineManager.loadMonthGroup({ year: 2024, month: 2 });
-      await timelineManager.loadMonthGroup({ year: 2024, month: 3 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 1 }));
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 2 }));
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 3 }));

      const [assetOne, assetTwo, assetThree] = await getAssets(timelineManager);
      timelineManager.removeAssets([assetTwo.id]);
@@ -523,7 +516,7 @@ describe('TimelineManager', () => {
    });

    it('returns null when no more assets', async () => {
-      await timelineManager.loadMonthGroup({ year: 2024, month: 3 });
+      await timelineManager.loadSegment(getSegmentIdentifier({ year: 2024, month: 3 }));
      expect(await timelineManager.getLaterAsset(timelineManager.months[0].getFirstAsset())).toBeUndefined();
    });
  });
@@ -554,7 +547,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-02-15T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([assetOne, assetTwo]);
+      timelineManager.upsertAssets([assetOne, assetTwo]);

      expect(timelineManager.getMonthGroupByAssetId(assetTwo.id)?.yearMonth.year).toEqual(2024);
      expect(timelineManager.getMonthGroupByAssetId(assetTwo.id)?.yearMonth.month).toEqual(2);
@@ -573,7 +566,7 @@ describe('TimelineManager', () => {
          fileCreatedAt: fromISODateTimeUTCToObject('2024-02-15T12:00:00.000Z'),
        }),
      );
-      timelineManager.addAssets([assetOne, assetTwo]);
+      timelineManager.upsertAssets([assetOne, assetTwo]);

      timelineManager.removeAssets([assetTwo.id]);
      expect(timelineManager.getMonthGroupByAssetId(assetOne.id)?.yearMonth.year).toEqual(2024);
--- a/web/src/lib/managers/timeline-manager/timeline-manager.svelte.ts
+++ b/web/src/lib/managers/timeline-manager/timeline-manager.svelte.ts
@@ -3,18 +3,19 @@ import { AssetOrder, getAssetInfo, getTimeBuckets } from '@immich/sdk';
 import { authManager } from '$lib/managers/auth-manager.svelte';

 import { CancellableTask } from '$lib/utils/cancellable-task';
-import { toTimelineAsset, type TimelineDateTime, type TimelineYearMonth } from '$lib/utils/timeline-util';
-
-import { clamp, debounce, isEqual } from 'lodash-es';
-import { SvelteDate, SvelteMap, SvelteSet } from 'svelte/reactivity';
-
-import { updateIntersectionMonthGroup } from '$lib/managers/timeline-manager/internal/intersection-support.svelte';
-import { updateGeometry } from '$lib/managers/timeline-manager/internal/layout-support.svelte';
-import { loadFromTimeBuckets } from '$lib/managers/timeline-manager/internal/load-support.svelte';
 import {
-  addAssetsToMonthGroups,
-  runAssetOperation,
-} from '$lib/managers/timeline-manager/internal/operations-support.svelte';
+  getSegmentIdentifier,
+  toTimelineAsset,
+  type TimelineDateTime,
+  type TimelineYearMonth,
+} from '$lib/utils/timeline-util';
+
+import { isEqual } from 'lodash-es';
+import { SvelteDate, SvelteSet } from 'svelte/reactivity';
+
+import { PhotostreamManager } from '$lib/managers/photostream-manager/PhotostreamManager.svelte';
+import { GroupInsertionCache } from '$lib/managers/timeline-manager/group-insertion-cache.svelte';
+import { updateGeometry } from '$lib/managers/timeline-manager/internal/layout-support.svelte';
 import {
  findMonthGroupForAsset as findMonthGroupForAssetUtil,
  findMonthGroupForDate,
@@ -24,37 +25,15 @@ import {
 } from '$lib/managers/timeline-manager/internal/search-support.svelte';
 import { WebsocketSupport } from '$lib/managers/timeline-manager/internal/websocket-support.svelte';
 import { DayGroup } from './day-group.svelte';
-import { isMismatched, updateObject } from './internal/utils.svelte';
+import { isMismatched } from './internal/utils.svelte';
 import { MonthGroup } from './month-group.svelte';
-import type {
-  AssetDescriptor,
-  AssetOperation,
-  Direction,
-  ScrubberMonth,
-  TimelineAsset,
-  TimelineManagerLayoutOptions,
-  TimelineManagerOptions,
-  Viewport,
-} from './types';
-
-export class TimelineManager {
-  isInitialized = $state(false);
-  months: MonthGroup[] = $state([]);
-  topSectionHeight = $state(0);
-  timelineHeight = $derived(this.months.reduce((accumulator, b) => accumulator + b.height, 0) + this.topSectionHeight);
-  assetCount = $derived(this.months.reduce((accumulator, b) => accumulator + b.assetsCount, 0));
+import type { AssetDescriptor, Direction, ScrubberMonth, TimelineAsset, TimelineManagerOptions } from './types';

+export class TimelineManager extends PhotostreamManager {
  albumAssets: Set<string> = new SvelteSet();
-
  scrubberMonths: ScrubberMonth[] = $state([]);
  scrubberTimelineHeight: number = $state(0);
-
-  topIntersectingMonthGroup: MonthGroup | undefined = $state();
-
-  visibleWindow = $derived.by(() => ({
-    top: this.#scrollTop,
-    bottom: this.#scrollTop + this.viewportHeight,
-  }));
+  #months: MonthGroup[] = $state([]);

  initTask = new CancellableTask(
    () => {
@@ -72,121 +51,16 @@ export class TimelineManager {
  );

  static #INIT_OPTIONS = {};
-  #viewportHeight = $state(0);
-  #viewportWidth = $state(0);
-  #scrollTop = $state(0);
+
  #websocketSupport: WebsocketSupport | undefined;
-
-  #rowHeight = $state(235);
-  #headerHeight = $state(48);
-  #gap = $state(12);
-
  #options: TimelineManagerOptions = TimelineManager.#INIT_OPTIONS;

-  #scrolling = $state(false);
-  #suspendTransitions = $state(false);
-  #resetScrolling = debounce(() => (this.#scrolling = false), 1000);
-  #resetSuspendTransitions = debounce(() => (this.suspendTransitions = false), 1000);
-  scrollCompensation: {
-    heightDelta: number | undefined;
-    scrollTop: number | undefined;
-    monthGroup: MonthGroup | undefined;
-  } = $state({
-    heightDelta: 0,
-    scrollTop: 0,
-    monthGroup: undefined,
-  });
-
-  constructor() {}
-
-  setLayoutOptions({ headerHeight = 48, rowHeight = 235, gap = 12 }: TimelineManagerLayoutOptions) {
-    let changed = false;
-    changed ||= this.#setHeaderHeight(headerHeight);
-    changed ||= this.#setGap(gap);
-    changed ||= this.#setRowHeight(rowHeight);
-    if (changed) {
-      this.refreshLayout();
-    }
+  get months() {
+    return this.#months;
  }

-  #setHeaderHeight(value: number) {
-    if (this.#headerHeight == value) {
-      return false;
-    }
-    this.#headerHeight = value;
-    return true;
-  }
-
-  get headerHeight() {
-    return this.#headerHeight;
-  }
-
-  #setGap(value: number) {
-    if (this.#gap == value) {
-      return false;
-    }
-    this.#gap = value;
-    return true;
-  }
-
-  get gap() {
-    return this.#gap;
-  }
-
-  #setRowHeight(value: number) {
-    if (this.#rowHeight == value) {
-      return false;
-    }
-    this.#rowHeight = value;
-    return true;
-  }
-
-  get rowHeight() {
-    return this.#rowHeight;
-  }
-
-  set scrolling(value: boolean) {
-    this.#scrolling = value;
-    if (value) {
-      this.suspendTransitions = true;
-      this.#resetScrolling();
-    }
-  }
-
-  get scrolling() {
-    return this.#scrolling;
-  }
-
-  set suspendTransitions(value: boolean) {
-    this.#suspendTransitions = value;
-    if (value) {
-      this.#resetSuspendTransitions();
-    }
-  }
-
-  get suspendTransitions() {
-    return this.#suspendTransitions;
-  }
-
-  set viewportWidth(value: number) {
-    const changed = value !== this.#viewportWidth;
-    this.#viewportWidth = value;
-    this.suspendTransitions = true;
-    void this.#updateViewportGeometry(changed);
-  }
-
-  get viewportWidth() {
-    return this.#viewportWidth;
-  }
-
-  set viewportHeight(value: number) {
-    this.#viewportHeight = value;
-    this.#suspendTransitions = true;
-    void this.#updateViewportGeometry(false);
-  }
-
-  get viewportHeight() {
-    return this.#viewportHeight;
+  get options() {
+    return this.#options;
  }

  async *assetsIterator(options?: {
@@ -198,7 +72,7 @@ export class TimelineManager {
    const direction = options?.direction ?? 'earlier';
    let { startDayGroup, startAsset } = options ?? {};
    for (const monthGroup of this.monthGroupIterator({ direction, startMonthGroup: options?.startMonthGroup })) {
-      await this.loadMonthGroup(monthGroup.yearMonth, { cancelable: false });
+      await this.loadSegment(monthGroup.identifier, { cancelable: false });
      yield* monthGroup.assetsIterator({ startDayGroup, startAsset, direction });
      startDayGroup = startAsset = undefined;
    }
@@ -234,75 +108,24 @@ export class TimelineManager {
    this.#websocketSupport = undefined;
  }

-  updateSlidingWindow(scrollTop: number) {
-    if (this.#scrollTop !== scrollTop) {
-      this.#scrollTop = scrollTop;
-      this.updateIntersections();
-    }
-  }
-
-  clearScrollCompensation() {
-    this.scrollCompensation = {
-      heightDelta: undefined,
-      scrollTop: undefined,
-      monthGroup: undefined,
-    };
-  }
-
-  updateIntersections() {
-    if (!this.isInitialized || this.visibleWindow.bottom === this.visibleWindow.top) {
-      return;
-    }
-    let topIntersectingMonthGroup = undefined;
-    for (const month of this.months) {
-      updateIntersectionMonthGroup(this, month);
-      if (!topIntersectingMonthGroup && month.actuallyIntersecting) {
-        topIntersectingMonthGroup = month;
-      }
-    }
-    if (topIntersectingMonthGroup !== undefined && this.topIntersectingMonthGroup !== topIntersectingMonthGroup) {
-      this.topIntersectingMonthGroup = topIntersectingMonthGroup;
-    }
-    for (const month of this.months) {
-      if (month === this.topIntersectingMonthGroup) {
-        this.topIntersectingMonthGroup.percent = clamp(
-          (this.visibleWindow.top - this.topIntersectingMonthGroup.top) / this.topIntersectingMonthGroup.height,
-          0,
-          1,
-        );
-      } else {
-        month.percent = 0;
-      }
-    }
-  }
-
-  clearDeferredLayout(month: MonthGroup) {
-    const hasDeferred = month.dayGroups.some((group) => group.deferredLayout);
-    if (hasDeferred) {
-      updateGeometry(this, month, { invalidateHeight: true, noDefer: true });
-      for (const group of month.dayGroups) {
-        group.deferredLayout = false;
-      }
-    }
-  }
-
  async #initializeMonthGroups() {
    const timebuckets = await getTimeBuckets({
      ...authManager.params,
      ...this.#options,
    });

-    this.months = timebuckets.map((timeBucket) => {
+    this.#months = timebuckets.map((timeBucket) => {
      const date = new SvelteDate(timeBucket.timeBucket);
      return new MonthGroup(
        this,
        { year: date.getUTCFullYear(), month: date.getUTCMonth() + 1 },
        timeBucket.count,
+        false,
        this.#options.order,
      );
    });
    this.albumAssets.clear();
-    this.#updateViewportGeometry(false);
+    this.updateViewportGeometry(false);
  }

  async updateOptions(options: TimelineManagerOptions) {
@@ -313,16 +136,16 @@ export class TimelineManager {
      return;
    }
    await this.initTask.reset();
-    await this.#init(options);
-    this.#updateViewportGeometry(false);
+    this.#options = options;
+    await this.init();
+    this.updateViewportGeometry(false);
  }

-  async #init(options: TimelineManagerOptions) {
+  async init() {
    this.isInitialized = false;
-    this.months = [];
+    this.#months = [];
    this.albumAssets.clear();
    await this.initTask.execute(async () => {
-      this.#options = options;
      await this.#initializeMonthGroups();
    }, true);
  }
@@ -332,36 +155,8 @@ export class TimelineManager {
    this.isInitialized = false;
  }

-  async updateViewport(viewport: Viewport) {
-    if (viewport.height === 0 && viewport.width === 0) {
-      return;
-    }
-
-    if (this.viewportHeight === viewport.height && this.viewportWidth === viewport.width) {
-      return;
-    }
-
-    if (!this.initTask.executed) {
-      await (this.initTask.loading ? this.initTask.waitUntilCompletion() : this.#init(this.#options));
-    }
-
-    const changedWidth = viewport.width !== this.viewportWidth;
-    this.viewportHeight = viewport.height;
-    this.viewportWidth = viewport.width;
-    this.#updateViewportGeometry(changedWidth);
-  }
-
-  #updateViewportGeometry(changedWidth: boolean) {
-    if (!this.isInitialized) {
-      return;
-    }
-    if (this.viewportWidth === 0 || this.viewportHeight === 0) {
-      return;
-    }
-    for (const month of this.months) {
-      updateGeometry(this, month, { invalidateHeight: changedWidth });
-    }
-    this.updateIntersections();
+  updateViewportGeometry(changedWidth: boolean) {
+    super.updateViewportGeometry(changedWidth);
    this.#createScrubberMonths();
  }

@@ -376,45 +171,6 @@ export class TimelineManager {
    this.scrubberTimelineHeight = this.timelineHeight;
  }

-  createLayoutOptions() {
-    const viewportWidth = this.viewportWidth;
-
-    return {
-      spacing: 2,
-      heightTolerance: 0.15,
-      rowHeight: this.#rowHeight,
-      rowWidth: Math.floor(viewportWidth),
-    };
-  }
-
-  async loadMonthGroup(yearMonth: TimelineYearMonth, options?: { cancelable: boolean }): Promise<void> {
-    let cancelable = true;
-    if (options) {
-      cancelable = options.cancelable;
-    }
-    const monthGroup = getMonthGroupByDate(this, yearMonth);
-    if (!monthGroup) {
-      return;
-    }
-
-    if (monthGroup.loader?.executed) {
-      return;
-    }
-
-    const result = await monthGroup.loader?.execute(async (signal: AbortSignal) => {
-      await loadFromTimeBuckets(this, monthGroup, this.#options, signal);
-    }, cancelable);
-    if (result === 'LOADED') {
-      updateIntersectionMonthGroup(this, monthGroup);
-    }
-  }
-
-  addAssets(assets: TimelineAsset[]) {
-    const assetsToUpdate = assets.filter((asset) => !this.isExcluded(asset));
-    const notUpdated = this.updateAssets(assetsToUpdate);
-    addAssetsToMonthGroups(this, [...notUpdated], { order: this.#options.order ?? AssetOrder.Desc });
-  }
-
  async findMonthGroupForAsset(id: string) {
    if (!this.isInitialized) {
      await this.initTask.waitUntilCompletion();
@@ -442,7 +198,7 @@ export class TimelineManager {
  }

  async #loadMonthGroupAtTime(yearMonth: TimelineYearMonth, options?: { cancelable: boolean }) {
-    await this.loadMonthGroup(yearMonth, options);
+    await this.loadSegment(getSegmentIdentifier(yearMonth), options);
    return getMonthGroupByDate(this, yearMonth);
  }

@@ -454,7 +210,7 @@ export class TimelineManager {
  async getRandomMonthGroup() {
    const random = Math.floor(Math.random() * this.months.length);
    const month = this.months[random];
-    await this.loadMonthGroup(month.yearMonth, { cancelable: false });
+    await this.loadSegment(getSegmentIdentifier(month.yearMonth), { cancelable: false });
    return month;
  }

@@ -463,40 +219,6 @@ export class TimelineManager {
    return month?.getRandomAsset();
  }

-  updateAssetOperation(ids: string[], operation: AssetOperation) {
-    runAssetOperation(this, new SvelteSet(ids), operation, { order: this.#options.order ?? AssetOrder.Desc });
-  }
-
-  updateAssets(assets: TimelineAsset[]) {
-    const lookup = new SvelteMap<string, TimelineAsset>(assets.map((asset) => [asset.id, asset]));
-    const { unprocessedIds } = runAssetOperation(
-      this,
-      new SvelteSet(lookup.keys()),
-      (asset) => {
-        updateObject(asset, lookup.get(asset.id));
-        return { remove: false };
-      },
-      { order: this.#options.order ?? AssetOrder.Desc },
-    );
-    const result: TimelineAsset[] = [];
-    for (const id of unprocessedIds.values()) {
-      result.push(lookup.get(id)!);
-    }
-    return result;
-  }
-
-  removeAssets(ids: string[]) {
-    const { unprocessedIds } = runAssetOperation(
-      this,
-      new SvelteSet(ids),
-      () => {
-        return { remove: true };
-      },
-      { order: this.#options.order ?? AssetOrder.Desc },
-    );
-    return [...unprocessedIds];
-  }
-
  refreshLayout() {
    for (const month of this.months) {
      updateGeometry(this, month, { invalidateHeight: true });
@@ -527,7 +249,7 @@ export class TimelineManager {
    if (!monthGroup) {
      return;
    }
-    await this.loadMonthGroup(dateTime, { cancelable: false });
+    await this.loadSegment(getSegmentIdentifier(dateTime), { cancelable: false });
    const asset = monthGroup.findClosest(dateTime);
    if (asset) {
      return asset;
@@ -552,4 +274,42 @@ export class TimelineManager {
  getAssetOrder() {
    return this.#options.order ?? AssetOrder.Desc;
  }
+
+  protected createUpsertContext(): unknown {
+    return new GroupInsertionCache();
+  }
+
+  protected upsertAssetIntoSegment(asset: TimelineAsset, context: GroupInsertionCache): void {
+    let month = getMonthGroupByDate(this, asset.localDateTime);
+
+    if (!month) {
+      month = new MonthGroup(this, asset.localDateTime, 1, true, this.#options.order);
+      this.months.push(month);
+    }
+
+    month.addTimelineAsset(asset, context);
+  }
+
+  protected postCreateSegments(): void {
+    this.months.sort((a, b) => {
+      return a.yearMonth.year === b.yearMonth.year
+        ? b.yearMonth.month - a.yearMonth.month
+        : b.yearMonth.year - a.yearMonth.year;
+    });
+  }
+
+  protected postUpsert(context: GroupInsertionCache): void {
+    for (const group of context.existingDayGroups) {
+      group.sortAssets(this.#options.order);
+    }
+
+    for (const monthGroup of context.bucketsWithNewDayGroups) {
+      monthGroup.sortDayGroups();
+    }
+
+    for (const month of context.updatedBuckets) {
+      month.sortDayGroups();
+      updateGeometry(this, month, { invalidateHeight: true });
+    }
+  }
 }
--- a/web/src/lib/managers/timeline-manager/types.ts
+++ b/web/src/lib/managers/timeline-manager/types.ts
@@ -35,7 +35,7 @@ export type TimelineAsset = {
  longitude?: number | null;
 };

-export type AssetOperation = (asset: TimelineAsset) => { remove: boolean };
+export type AssetOperation = (asset: TimelineAsset) => { remove: boolean } | unknown;

 export type MoveAsset = { asset: TimelineAsset; date: TimelineDate };

--- a/web/src/lib/utils/actions.ts
+++ b/web/src/lib/utils/actions.ts
@@ -21,15 +21,15 @@ export type OnSetVisibility = (ids: string[]) => void;

 export const deleteAssets = async (
  force: boolean,
-  onAssetDelete: OnDelete,
+  onAssetDelete: OnDelete | undefined,
  assets: TimelineAsset[],
-  onUndoDelete: OnUndoDelete | undefined = undefined,
+  onUndoDelete: OnUndoDelete | undefined,
 ) => {
  const $t = get(t);
  try {
    const ids = assets.map((a) => a.id);
    await deleteBulk({ assetBulkDeleteDto: { ids, force } });
-    onAssetDelete(ids);
+    onAssetDelete?.(ids);

    notificationController.show({
      message: force
@@ -98,5 +98,5 @@ export function updateUnstackedAssetInTimeline(timelineManager: TimelineManager,
    },
  );

-  timelineManager.addAssets(assets);
+  timelineManager.upsertAssets(assets);
 }
--- a/web/src/lib/utils/asset-utils.ts
+++ b/web/src/lib/utils/asset-utils.ts
@@ -513,7 +513,7 @@ export const selectAllAssets = async (timelineManager: TimelineManager, assetInt

  try {
    for (const monthGroup of timelineManager.months) {
-      await timelineManager.loadMonthGroup(monthGroup.yearMonth);
+      await timelineManager.loadSegment(monthGroup.identifier);

      if (!get(isSelectingAllAssets)) {
        assetInteraction.clearMultiselect();
--- a/web/src/lib/utils/timeline-util.ts
+++ b/web/src/lib/utils/timeline-util.ts
@@ -1,3 +1,4 @@
+import type { MonthGroup } from '$lib/managers/timeline-manager/month-group.svelte';
 import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
 import { locale } from '$lib/stores/preferences.store';
 import { getAssetRatio } from '$lib/utils/asset-utils';
@@ -23,11 +24,11 @@ export type TimelineDateTime = TimelineDate & {
  millisecond: number;
 };

-export type ScrubberListener = (
-  scrubberMonth: { year: number; month: number },
-  overallScrollPercent: number,
-  scrubberMonthScrollPercent: number,
-) => void | Promise<void>;
+export type ScrubberListener = (scrubberData: {
+  scrubberMonth: { year: number; month: number };
+  overallScrollPercent: number;
+  scrubberMonthScrollPercent: number;
+}) => void | Promise<void>;

 // used for AssetResponseDto.dateTimeOriginal, amongst others
 export const fromISODateTime = (isoDateTime: string, timeZone: string): DateTime<true> =>
@@ -151,6 +152,14 @@ export function formatGroupTitle(_date: DateTime): string {
  return getDateLocaleString(date, { locale: get(locale) });
 }

+export const formatGroupTitleFull = (_date: DateTime): string => {
+  if (!_date.isValid) {
+    return _date.toString();
+  }
+  const date = _date as DateTime<true>;
+  return getDateLocaleString(date);
+};
+
 export const getDateLocaleString = (date: DateTime, opts?: LocaleOptions): string =>
  date.toLocaleString(DateTime.DATE_MED_WITH_WEEKDAY, opts);

@@ -234,3 +243,11 @@ export function setDifference<T>(setA: Set<T>, setB: Set<T>): SvelteSet<T> {
  }
  return result;
 }
+
+export const getSegmentIdentifier = (yearMonth: TimelineYearMonth | TimelineDateTime) => ({
+  matches(segment: MonthGroup) {
+    return (
+      segment.yearMonth && segment.yearMonth.year === yearMonth.year && segment.yearMonth.month === yearMonth.month
+    );
+  },
+});
--- a/web/src/routes/(user)/albums/[albumId=id]/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/albums/[albumId=id]/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -34,7 +34,6 @@
  import { AlbumPageViewMode, AppRoute } from '$lib/constants';
  import { activityManager } from '$lib/managers/activity-manager.svelte';
  import { TimelineManager } from '$lib/managers/timeline-manager/timeline-manager.svelte';
-  import type { TimelineAsset } from '$lib/managers/timeline-manager/types';
  import AlbumOptionsModal from '$lib/modals/AlbumOptionsModal.svelte';
  import AlbumShareModal from '$lib/modals/AlbumShareModal.svelte';
  import AlbumUsersModal from '$lib/modals/AlbumUsersModal.svelte';
@@ -262,18 +261,15 @@
    }
  };

-  const handleSetVisibility = (assetIds: string[]) => {
-    timelineManager.removeAssets(assetIds);
+  const handleSetVisibility = () => {
    assetInteraction.clearMultiselect();
  };

-  const handleRemoveAssets = async (assetIds: string[]) => {
-    timelineManager.removeAssets(assetIds);
+  const handleRemoveAssets = async () => {
    await refreshAlbum();
  };

-  const handleUndoRemoveAssets = async (assets: TimelineAsset[]) => {
-    timelineManager.addAssets(assets);
+  const handleUndoRemoveAssets = async () => {
    await refreshAlbum();
  };

@@ -572,14 +568,7 @@
          <AddToAlbum shared />
        </ButtonContextMenu>
        {#if assetInteraction.isAllUserOwned}
-          <FavoriteAction
-            removeFavorite={assetInteraction.isAllFavorite}
-            onFavorite={(ids, isFavorite) =>
-              timelineManager.updateAssetOperation(ids, (asset) => {
-                asset.isFavorite = isFavorite;
-                return { remove: false };
-              })}
-          ></FavoriteAction>
+          <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager}></FavoriteAction>
        {/if}
        <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')} offset={{ x: 175, y: 25 }}>
          <DownloadAction menuItem filename="{album.albumName}.zip" />
@@ -594,7 +583,7 @@
                onClick={() => updateThumbnailUsingCurrentSelection()}
              />
            {/if}
-            <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} />
+            <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} manager={timelineManager} />
            <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
          {/if}

@@ -606,7 +595,12 @@
            <RemoveFromAlbum menuItem bind:album onRemove={handleRemoveAssets} />
          {/if}
          {#if assetInteraction.isAllUserOwned}
-            <DeleteAssets menuItem onAssetDelete={handleRemoveAssets} onUndoDelete={handleUndoRemoveAssets} />
+            <DeleteAssets
+              menuItem
+              onAssetDelete={handleRemoveAssets}
+              onUndoDelete={handleUndoRemoveAssets}
+              manager={timelineManager}
+            />
          {/if}
        </ButtonContextMenu>
      </AssetSelectControlBar>
--- a/web/src/routes/(user)/archive/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/archive/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -65,32 +65,18 @@
    assets={assetInteraction.selectedAssets}
    clearSelect={() => assetInteraction.clearMultiselect()}
  >
-    <ArchiveAction
-      unarchive
-      onArchive={(ids, visibility) =>
-        timelineManager.updateAssetOperation(ids, (asset) => {
-          asset.visibility = visibility;
-          return { remove: false };
-        })}
-    />
+    <ArchiveAction unarchive manager={timelineManager} />
    <CreateSharedLink />
    <SelectAllAssets {timelineManager} {assetInteraction} />
    <ButtonContextMenu icon={mdiPlus} title={$t('add_to')}>
      <AddToAlbum />
      <AddToAlbum shared />
    </ButtonContextMenu>
-    <FavoriteAction
-      removeFavorite={assetInteraction.isAllFavorite}
-      onFavorite={(ids, isFavorite) =>
-        timelineManager.updateAssetOperation(ids, (asset) => {
-          asset.isFavorite = isFavorite;
-          return { remove: false };
-        })}
-    />
+    <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager} />
    <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')}>
      <DownloadAction menuItem />
      <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
-      <DeleteAssets menuItem onAssetDelete={(assetIds) => timelineManager.removeAssets(assetIds)} />
+      <DeleteAssets menuItem manager={timelineManager} />
    </ButtonContextMenu>
  </AssetSelectControlBar>
 {/if}
--- a/web/src/routes/(user)/favorites/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/favorites/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -71,7 +71,7 @@
    assets={assetInteraction.selectedAssets}
    clearSelect={() => assetInteraction.clearMultiselect()}
  >
-    <FavoriteAction removeFavorite onFavorite={(assetIds) => timelineManager.removeAssets(assetIds)} />
+    <FavoriteAction removeFavorite manager={timelineManager} />
    <CreateSharedLink />
    <SelectAllAssets {timelineManager} {assetInteraction} />
    <ButtonContextMenu icon={mdiPlus} title={$t('add_to')}>
@@ -83,20 +83,12 @@
      <ChangeDate menuItem />
      <ChangeDescription menuItem />
      <ChangeLocation menuItem />
-      <ArchiveAction
-        menuItem
-        unarchive={assetInteraction.isAllArchived}
-        onArchive={(assetIds) => timelineManager.removeAssets(assetIds)}
-      />
+      <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} manager={timelineManager} />
      {#if $preferences.tags.enabled}
        <TagAction menuItem />
      {/if}
      <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
-      <DeleteAssets
-        menuItem
-        onAssetDelete={(assetIds) => timelineManager.removeAssets(assetIds)}
-        onUndoDelete={(assets) => timelineManager.addAssets(assets)}
-      />
+      <DeleteAssets menuItem manager={timelineManager} />
    </ButtonContextMenu>
  </AssetSelectControlBar>
 {/if}
--- a/web/src/routes/(user)/people/[personId]/[[photos=photos]]/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/people/[personId]/[[photos=photos]]/[[assetId=id]]/+page.svelte
@@ -349,15 +349,8 @@
    }
  };

-  const handleDeleteAssets = async (assetIds: string[]) => {
-    timelineManager.removeAssets(assetIds);
-    await updateAssetCount();
-  };
-
-  const handleUndoDeleteAssets = async (assets: TimelineAsset[]) => {
-    timelineManager.addAssets(assets);
-    await updateAssetCount();
-  };
+  const handleDeleteAssets = async () => await updateAssetCount();
+  const handleUndoDeleteAssets = async () => await updateAssetCount();

  let person = $derived(data.person);

@@ -511,14 +504,7 @@
        <AddToAlbum />
        <AddToAlbum shared />
      </ButtonContextMenu>
-      <FavoriteAction
-        removeFavorite={assetInteraction.isAllFavorite}
-        onFavorite={(ids, isFavorite) =>
-          timelineManager.updateAssetOperation(ids, (asset) => {
-            asset.isFavorite = isFavorite;
-            return { remove: false };
-          })}
-      />
+      <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager} />
      <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')}>
        <DownloadAction menuItem filename="{person.name || 'immich'}.zip" />
        <MenuOption
@@ -529,19 +515,16 @@
        <ChangeDate menuItem />
        <ChangeDescription menuItem />
        <ChangeLocation menuItem />
-        <ArchiveAction
-          menuItem
-          unarchive={assetInteraction.isAllArchived}
-          onArchive={(assetIds) => timelineManager.removeAssets(assetIds)}
-        />
+        <ArchiveAction menuItem unarchive={assetInteraction.isAllArchived} manager={timelineManager} />
        {#if $preferences.tags.enabled && assetInteraction.isAllUserOwned}
          <TagAction menuItem />
        {/if}
        <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
        <DeleteAssets
          menuItem
-          onAssetDelete={(assetIds) => handleDeleteAssets(assetIds)}
-          onUndoDelete={(assets) => handleUndoDeleteAssets(assets)}
+          manager={timelineManager}
+          onAssetDelete={handleDeleteAssets}
+          onUndoDelete={handleUndoDeleteAssets}
        />
      </ButtonContextMenu>
    </AssetSelectControlBar>
--- a/web/src/routes/(user)/photos/[[assetId=id]]/+page.svelte
+++ b/web/src/routes/(user)/photos/[[assetId=id]]/+page.svelte
@@ -70,12 +70,12 @@

  const handleLink: OnLink = ({ still, motion }) => {
    timelineManager.removeAssets([motion.id]);
-    timelineManager.updateAssets([still]);
+    timelineManager.upsertAssets([still]);
  };

  const handleUnlink: OnUnlink = ({ still, motion }) => {
-    timelineManager.addAssets([motion]);
-    timelineManager.updateAssets([still]);
+    timelineManager.upsertAssets([motion]);
+    timelineManager.upsertAssets([still]);
  };

  const handleSetVisibility = (assetIds: string[]) => {
@@ -118,14 +118,7 @@
      <AddToAlbum />
      <AddToAlbum shared />
    </ButtonContextMenu>
-    <FavoriteAction
-      removeFavorite={assetInteraction.isAllFavorite}
-      onFavorite={(ids, isFavorite) =>
-        timelineManager.updateAssetOperation(ids, (asset) => {
-          asset.isFavorite = isFavorite;
-          return { remove: false };
-        })}
-    ></FavoriteAction>
+    <FavoriteAction removeFavorite={assetInteraction.isAllFavorite} manager={timelineManager}></FavoriteAction>
    <ButtonContextMenu icon={mdiDotsVertical} title={$t('menu')}>
      <DownloadAction menuItem />
      {#if assetInteraction.selectedAssets.length > 1 || isAssetStackSelected}
@@ -146,15 +139,11 @@
      <ChangeDate menuItem />
      <ChangeDescription menuItem />
      <ChangeLocation menuItem />
-      <ArchiveAction menuItem onArchive={(assetIds) => timelineManager.removeAssets(assetIds)} />
+      <ArchiveAction menuItem manager={timelineManager} />
      {#if $preferences.tags.enabled}
        <TagAction menuItem />
      {/if}
-      <DeleteAssets
-        menuItem
-        onAssetDelete={(assetIds) => timelineManager.removeAssets(assetIds)}
-        onUndoDelete={(assets) => timelineManager.addAssets(assets)}
-      />
+      <DeleteAssets menuItem manager={timelineManager} />
      <SetVisibilityAction menuItem onVisibilitySet={handleSetVisibility} />
      <hr />
      <AssetJobActions />
--- a/web/src/routes/(user)/utilities/geolocation/+page.svelte
+++ b/web/src/routes/(user)/utilities/geolocation/+page.svelte
@@ -63,7 +63,7 @@
      }),
    );

-    timelineManager.updateAssets(updatedAssets);
+    timelineManager.upsertAssets(updatedAssets);

    handleDeselectAll();
  };
@@ -195,7 +195,7 @@
    withStacked
    onThumbnailClick={handleThumbnailClick}
  >
-    {#snippet customLayout(asset: TimelineAsset)}
+    {#snippet customThumbnailLayout(asset: TimelineAsset)}
      {#if hasGps(asset)}
        <div class="absolute bottom-1 end-3 px-4 py-1 rounded-xl text-xs transition-colors bg-success text-black">
          {asset.city || $t('gps')}
Author	SHA1	Message	Date
midzelis	0168353c2d	refactor(web): extract asset grid layout logic into AssetLayout component - Extracts the asset grid rendering logic from `MonthSegment` into a dedicated `AssetLayout` component - Simplifies `MonthSegment` by delegating layout responsibilities while maintaining all existing functionality - Renames `customLayout` prop to `customThumbnailLayout` for clarity across Timeline components ## Changes - Created new `AssetLayout.svelte` component that handles: - Asset grid rendering with proper positioning - Animation transitions - Filtering of intersecting viewer assets - Updated `MonthSegment.svelte` to use `AssetLayout` via composition pattern - Renamed `customLayout` to `customThumbnailLayout` in Timeline and related components - Moved thumbnail click and selection logic to Timeline parent component using snippets	2025-09-30 00:08:14 +00:00
midzelis	c44b315117	refactor(web): consolidate asset operations in PhotostreamManager base class Moves common asset operation methods (upsertAssets, removeAssets, updateAssetOperation) from TimelineManager into PhotostreamManager base class, making them available to all photostream implementations. Updates all consuming components to use the more accurate 'upsertAssets' naming instead of separate 'addAssets' and 'updateAssets' methods. - Move asset operation methods to PhotostreamManager base class - Replace addAssets/updateAssets calls with unified upsertAssets method - Update type imports to use PhotostreamManager instead of TimelineManager - Remove operations-support.svelte.ts (functionality moved to base class) - Add abstract upsertAssetIntoSegment method for subclass customization	2025-09-30 00:00:50 +00:00
midzelis	98ab224791	refactor: adjust favorite, delete, and archive actions for timeline - Pass TimelineManager instance to timeline action components instead of callbacks - Move asset update logic (delete, archive, favorite) into action components	2025-09-29 01:26:59 +00:00
midzelis	e5fce47c0c	Rename TimelineDateGroup to MonthSegment	2025-09-28 19:41:41 +00:00
midzelis	3a468a3f50	refactor(web): extract common timeline functionality into PhotostreamManager base classes Create abstract PhotostreamManager and PhotostreamSegment base classes to enable reusable timeline-like components. This refactoring extracts common viewport management, scroll handling, and segment operations from TimelineManager and MonthGroup into reusable abstractions. Changes: - Add PhotostreamManager.svelte.ts with viewport and scroll management - Add PhotostreamSegment.svelte.ts with segment positioning and intersection logic - Refactor TimelineManager to extend PhotostreamManager - Refactor MonthGroup to extend PhotostreamSegment - Add utility functions for segment identification and date formatting - Update tests to reflect new inheritance structure	2025-09-28 19:41:41 +00:00
midzelis	e600cf64b0	refactor(web): extract asset viewer logic from Timeline into TimelineAssetViewer component - Extracted asset viewer navigation and action handling logic from Timeline.svelte into a dedicated TimelineAssetViewer component - Reduces Timeline.svelte complexity by ~150 lines and improves separation of concerns - No functional changes - purely a refactoring to improve code organization ## Changes - Created new TimelineAssetViewer.svelte component containing all asset viewer-related logic - Moved handlePrevious, handleNext, handleRandom, handleClose, handlePreAction, and handleAction methods - Timeline.svelte now only passes required props to the new component - Maintained all existing functionality including navigation, asset actions, and stack management	2025-09-28 19:41:41 +00:00
midzelis	41066b1c31	refactor(web): extract timeline keyboard actions into separate component Extracts keyboard shortcuts and related functionality from Timeline component into a dedicated TimelineKeyboardActions component for better separation of concerns and maintainability.	2025-09-28 19:41:41 +00:00
midzelis	9051fa6949	refactor(web): Clarify property names in Timeline and Scrubber Renamed properties across Timeline/Scrubber components for clarity: - scrubOverallPercent → timelineScrollPercent - scrubberMonthPercent → viewportTopMonthScrollPercent - scrubberMonth → viewportTopMonth - leadout → isInLeadOutSection Additional changes: - Updated ScrubberListener signature to accept object parameter - Added detailed JSDoc comments for all Scrubber props - Fixed callback invocations to use new object syntax - Aligned Timeline's local state variables with Scrubber prop names	2025-09-28 19:41:41 +00:00