Move Middleware to Jellyfin.Api

Jellyfin.Api/Middleware/UrlDecodeQueryFeature.cs

@@ -0,0 +1,84 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Jellyfin.Extensions;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Http.Features;
+using Microsoft.Extensions.Primitives;
+
+namespace Jellyfin.Api.Middleware
+{
+    /// <summary>
+    /// Defines the <see cref="UrlDecodeQueryFeature"/>.
+    /// </summary>
+    public class UrlDecodeQueryFeature : IQueryFeature
+    {
+        private IQueryCollection? _store;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="UrlDecodeQueryFeature"/> class.
+        /// </summary>
+        /// <param name="feature">The <see cref="IQueryFeature"/> instance.</param>
+        public UrlDecodeQueryFeature(IQueryFeature feature)
+        {
+            Query = feature.Query;
+        }
+
+        /// <summary>
+        /// Gets or sets a value indicating the url decoded <see cref="IQueryCollection"/>.
+        /// </summary>
+        public IQueryCollection Query
+        {
+            get
+            {
+                return _store ?? QueryCollection.Empty;
+            }
+
+            set
+            {
+                // Only interested in where the querystring is encoded which shows up as one key with nothing in the value.
+                if (value.Count != 1)
+                {
+                    _store = value;
+                    return;
+                }
+
+                // Encoded querystrings have no value, so don't process anything if a value is present.
+                var (key, stringValues) = value.First();
+                if (!string.IsNullOrEmpty(stringValues))
+                {
+                    _store = value;
+                    return;
+                }
+
+                if (!key.Contains('=', StringComparison.Ordinal))
+                {
+                    _store = value;
+                    return;
+                }
+
+                var pairs = new Dictionary<string, StringValues>();
+                foreach (var pair in key.SpanSplit('&'))
+                {
+                    var i = pair.IndexOf('=');
+                    if (i == -1)
+                    {
+                        // encoded is an equals.
+                        // We use TryAdd so duplicate keys get ignored
+                        pairs.TryAdd(pair.ToString(), StringValues.Empty);
+                        continue;
+                    }
+
+                    var k = pair[..i].ToString();
+                    var v = pair[(i + 1)..].ToString();
+                    if (!pairs.TryAdd(k, new StringValues(v)))
+                    {
+                        pairs[k] = StringValues.Concat(pairs[k], v);
+                    }
+                }
+
+                _store = new QueryCollection(pairs);
+            }
+        }
+    }
+}