feat(mobile): Remote thumbnails and images use an on-disk image cache

mobile/lib/modules/activities/widgets/activity_tile.dart

@@ -3,7 +3,7 @@ import 'package:hooks_riverpod/hooks_riverpod.dart';
 import 'package:immich_mobile/extensions/build_context_extensions.dart';
 import 'package:immich_mobile/extensions/datetime_extensions.dart';
 import 'package:immich_mobile/modules/activities/models/activity.model.dart';
-import 'package:immich_mobile/modules/asset_viewer/image_providers/immich_remote_image_provider.dart';
+import 'package:immich_mobile/modules/asset_viewer/image_providers/immich_remote_thumbnail_provider.dart';
 import 'package:immich_mobile/modules/asset_viewer/providers/current_asset.provider.dart';
 import 'package:immich_mobile/shared/ui/user_circle_avatar.dart';
 
@@ -106,9 +106,8 @@ class _ActivityAssetThumbnail extends StatelessWidget {
       decoration: BoxDecoration(
         borderRadius: const BorderRadius.all(Radius.circular(4)),
         image: DecorationImage(
-          image: ImmichRemoteImageProvider(
+          image: ImmichRemoteThumbnailProvider(
             assetId: assetId,
-            isThumbnail: true,
           ),
           fit: BoxFit.cover,
         ),

mobile/lib/modules/asset_viewer/image_providers/cache/image_loader.dart

@@ -0,0 +1,58 @@
+import 'dart:async';
+import 'dart:ui' as ui;
+
+import 'package:flutter/material.dart';
+import 'package:flutter_cache_manager/flutter_cache_manager.dart';
+import 'package:immich_mobile/modules/asset_viewer/image_providers/exceptions/image_loading_exception.dart';
+import 'package:immich_mobile/shared/models/store.dart';
+
+/// Loads the codec from the URI and sends the events to the [chunkEvents] stream
+///
+/// Credit to [flutter_cached_network_image](https://github.com/Baseflow/flutter_cached_network_image/blob/develop/cached_network_image/lib/src/image_provider/_image_loader.dart)
+/// for this wonderful implementation of their image loader
+class ImageLoader {
+  static Future<ui.Codec> loadImageFromCache(
+    String uri, {
+    required ImageCacheManager cache,
+    required ImageDecoderCallback decode,
+    StreamController<ImageChunkEvent>? chunkEvents,
+    int? height,
+    int? width,
+  }) async {
+    final headers = {
+      'x-immich-user-token': Store.get(StoreKey.accessToken),
+    };
+
+    final stream = cache.getImageFile(
+      uri,
+      withProgress: true,
+      headers: headers,
+      maxHeight: height,
+      maxWidth: width,
+    );
+
+    await for (final result in stream) {
+      if (result is DownloadProgress) {
+        // We are downloading the file, so update the [chunkEvents]
+        chunkEvents?.add(
+          ImageChunkEvent(
+            cumulativeBytesLoaded: result.downloaded,
+            expectedTotalBytes: result.totalSize,
+          ),
+        );
+      }
+
+      if (result is FileInfo) {
+        // We have the file
+        final file = result.file;
+        final bytes = await file.readAsBytes();
+        final buffer = await ui.ImmutableBuffer.fromUint8List(bytes);
+        final decoded = await decode(buffer);
+        return decoded;
+      }
+    }
+
+    // If we get here, the image failed to load from the cache stream
+    throw ImageLoadingException('Could not load image from stream');
+  }
+}

mobile/lib/modules/asset_viewer/image_providers/cache/remote_image_cache_manager.dart

@@ -0,0 +1,20 @@
+import 'package:flutter_cache_manager/flutter_cache_manager.dart';
+
+/// The cache manager for full size images [ImmichRemoteImageProvider]
+class RemoteImageCacheManager extends CacheManager with ImageCacheManager {
+  static const key = 'remoteImageCacheKey';
+  static final RemoteImageCacheManager _instance = RemoteImageCacheManager._();
+
+  factory RemoteImageCacheManager() {
+    return _instance;
+  }
+
+  RemoteImageCacheManager._()
+      : super(
+          Config(
+            key,
+            maxNrOfCacheObjects: 500,
+            stalePeriod: const Duration(days: 30),
+          ),
+        );
+}

mobile/lib/modules/asset_viewer/image_providers/cache/thumbnail_image_cache_manager.dart

@@ -0,0 +1,21 @@
+import 'package:flutter_cache_manager/flutter_cache_manager.dart';
+
+/// The cache manager for thumbnail images [ImmichRemoteThumbnailProvider]
+class ThumbnailImageCacheManager extends CacheManager with ImageCacheManager {
+  static const key = 'thumbnailImageCacheKey';
+  static final ThumbnailImageCacheManager _instance =
+      ThumbnailImageCacheManager._();
+
+  factory ThumbnailImageCacheManager() {
+    return _instance;
+  }
+
+  ThumbnailImageCacheManager._()
+      : super(
+          Config(
+            key,
+            maxNrOfCacheObjects: 5000,
+            stalePeriod: const Duration(days: 30),
+          ),
+        );
+}

mobile/lib/modules/asset_viewer/image_providers/exceptions/image_loading_exception.dart

@@ -0,0 +1,5 @@
+/// An exception for the [ImageLoader] and the Immich image providers
+class ImageLoadingException implements Exception {
+  final String message;
+  ImageLoadingException(this.message);
+}

mobile/lib/modules/asset_viewer/image_providers/immich_remote_image_provider.dart

@@ -1,8 +1,10 @@
 import 'dart:async';
-import 'dart:io';
 import 'dart:ui' as ui;
 
 import 'package:cached_network_image/cached_network_image.dart';
+import 'package:flutter_cache_manager/flutter_cache_manager.dart';
+import 'package:immich_mobile/modules/asset_viewer/image_providers/cache/image_loader.dart';
+import 'package:immich_mobile/modules/asset_viewer/image_providers/cache/remote_image_cache_manager.dart';
 import 'package:openapi/api.dart' as api;
 
 import 'package:flutter/foundation.dart';
@@ -12,24 +14,18 @@ import 'package:immich_mobile/shared/models/asset.dart';
 import 'package:immich_mobile/shared/models/store.dart';
 import 'package:immich_mobile/utils/image_url_builder.dart';
 
-/// Our Image Provider HTTP client to make the request
-final _httpClient = HttpClient()
-  ..autoUncompress = false
-  ..maxConnectionsPerHost = 10;
-
-/// The remote image provider
+/// The remote image provider for full size remote images
 class ImmichRemoteImageProvider
     extends ImageProvider<ImmichRemoteImageProvider> {
   /// The [Asset.remoteId] of the asset to fetch
   final String assetId;
 
-  // If this is a thumbnail, we stop at loading the
-  // smallest version of the remote image
-  final bool isThumbnail;
+  /// The image cache manager
+  final ImageCacheManager? cacheManager;
 
   ImmichRemoteImageProvider({
     required this.assetId,
-    this.isThumbnail = false,
+    this.cacheManager,
   });
 
   /// Converts an [ImageProvider]'s settings plus an [ImageConfiguration] to a key
@@ -46,9 +42,10 @@ class ImmichRemoteImageProvider
     ImmichRemoteImageProvider key,
     ImageDecoderCallback decode,
   ) {
+    final cache = cacheManager ?? RemoteImageCacheManager();
     final chunkEvents = StreamController<ImageChunkEvent>();
     return MultiImageStreamCompleter(
-      codec: _codec(key, decode, chunkEvents),
+      codec: _codec(key, cache, decode, chunkEvents),
       scale: 1.0,
       chunkEvents: chunkEvents.stream,
     );
@@ -69,82 +66,61 @@ class ImmichRemoteImageProvider
   // Streams in each stage of the image as we ask for it
   Stream<ui.Codec> _codec(
     ImmichRemoteImageProvider key,
+    ImageCacheManager cache,
     ImageDecoderCallback decode,
     StreamController<ImageChunkEvent> chunkEvents,
   ) async* {
     // Load a preview to the chunk events
-    if (_loadPreview || key.isThumbnail) {
+    if (_loadPreview) {
       final preview = getThumbnailUrlForRemoteId(
         key.assetId,
         type: api.ThumbnailFormat.WEBP,
       );
 
-      yield await _loadFromUri(
-        Uri.parse(preview),
-        decode,
-        chunkEvents,
+      yield await ImageLoader.loadImageFromCache(
+        preview,
+        cache: cache,
+        decode: decode,
+        chunkEvents: chunkEvents,
       );
     }
 
-    // Guard thumnbail rendering
-    if (key.isThumbnail) {
-      await chunkEvents.close();
-      return;
-    }
-
     // Load the higher resolution version of the image
     final url = getThumbnailUrlForRemoteId(
       key.assetId,
       type: api.ThumbnailFormat.JPEG,
     );
-    final codec = await _loadFromUri(Uri.parse(url), decode, chunkEvents);
+    final codec = await ImageLoader.loadImageFromCache(
+      url,
+      cache: cache,
+      decode: decode,
+      chunkEvents: chunkEvents,
+    );
     yield codec;
 
     // Load the final remote image
     if (_useOriginal) {
       // Load the original image
       final url = getImageUrlFromId(key.assetId);
-      final codec = await _loadFromUri(Uri.parse(url), decode, chunkEvents);
+      final codec = await ImageLoader.loadImageFromCache(
+        url,
+        cache: cache,
+        decode: decode,
+        chunkEvents: chunkEvents,
+      );
       yield codec;
     }
     await chunkEvents.close();
   }
 
-  // Loads the codec from the URI and sends the events to the [chunkEvents] stream
-  Future<ui.Codec> _loadFromUri(
-    Uri uri,
-    ImageDecoderCallback decode,
-    StreamController<ImageChunkEvent> chunkEvents,
-  ) async {
-    final request = await _httpClient.getUrl(uri);
-    request.headers.add(
-      'x-immich-user-token',
-      Store.get(StoreKey.accessToken),
-    );
-    final response = await request.close();
-    // Chunks of the completed image can be shown
-    final data = await consolidateHttpClientResponseBytes(
-      response,
-      onBytesReceived: (cumulative, total) {
-        chunkEvents.add(
-          ImageChunkEvent(
-            cumulativeBytesLoaded: cumulative,
-            expectedTotalBytes: total,
-          ),
-        );
-      },
-    );
-
-    // Decode the response
-    final buffer = await ui.ImmutableBuffer.fromUint8List(data);
-    return decode(buffer);
-  }
-
   @override
   bool operator ==(Object other) {
-    if (other is! ImmichRemoteImageProvider) return false;
     if (identical(this, other)) return true;
-    return assetId == other.assetId && isThumbnail == other.isThumbnail;
+    if (other is ImmichRemoteImageProvider) {
+      return assetId == other.assetId;
+    }
+
+    return false;
   }
 
   @override