feat(web): Improve duplicate suggestion (#14947)

* feat: Improve duplicate suggestion

* format

* feat(web): Add deduplication info popup

* fix: lint

* fmt

---------

Co-authored-by: Alex <alex.tran1502@gmail.com>

web/src/lib/utils/duplicate-utils.spec.ts

@@ -0,0 +1,37 @@
+import { suggestDuplicate } from '$lib/utils/duplicate-utils';
+import type { AssetResponseDto } from '@immich/sdk';
+
+describe('choosing a duplicate', () => {
+  it('picks the asset with the largest file size', () => {
+    const assets = [
+      { exifInfo: { fileSizeInByte: 300 } },
+      { exifInfo: { fileSizeInByte: 200 } },
+      { exifInfo: { fileSizeInByte: 100 } },
+    ];
+    expect(suggestDuplicate(assets as AssetResponseDto[])).toEqual(assets[0]);
+  });
+
+  it('picks the asset with the most exif data if multiple assets have the same file size', () => {
+    const assets = [
+      { exifInfo: { fileSizeInByte: 200, rating: 5, fNumber: 1 } },
+      { exifInfo: { fileSizeInByte: 200, rating: 5 } },
+      { exifInfo: { fileSizeInByte: 100, rating: 5 } },
+    ];
+    expect(suggestDuplicate(assets as AssetResponseDto[])).toEqual(assets[0]);
+  });
+
+  it('returns undefined for an empty array', () => {
+    const assets: AssetResponseDto[] = [];
+    expect(suggestDuplicate(assets)).toBeUndefined();
+  });
+
+  it('handles assets with no exifInfo', () => {
+    const assets = [{ exifInfo: { fileSizeInByte: 200 } }, {}];
+    expect(suggestDuplicate(assets as AssetResponseDto[])).toEqual(assets[0]);
+  });
+
+  it('handles assets with exifInfo but no fileSizeInByte', () => {
+    const assets = [{ exifInfo: { rating: 5, fNumber: 1 } }, { exifInfo: { rating: 5 } }];
+    expect(suggestDuplicate(assets as AssetResponseDto[])).toEqual(assets[0]);
+  });
+});