Address the real lifetime issue of the SDK's Client by making Context.mediaProvider weak. (#4466)

This reverts commit 927aea4bfe.

ElementX/Sources/Services/Client/ClientProxy.swift

@@ -17,7 +17,7 @@ class ClientProxy: ClientProxyProtocol {
     private let networkMonitor: NetworkMonitorProtocol
     private let appSettings: AppSettings
     
-    let mediaLoader: MediaLoaderProtocol
+    private let mediaLoader: MediaLoaderProtocol
     private let clientQueue: DispatchQueue
     
     private var roomListService: RoomListService
@@ -1113,6 +1113,20 @@ class ClientProxy: ClientProxyProtocol {
     }
 }
 
+extension ClientProxy: MediaLoaderProtocol {
+    func loadMediaContentForSource(_ source: MediaSourceProxy) async throws -> Data {
+        try await mediaLoader.loadMediaContentForSource(source)
+    }
+
+    func loadMediaThumbnailForSource(_ source: MediaSourceProxy, width: UInt, height: UInt) async throws -> Data {
+        try await mediaLoader.loadMediaThumbnailForSource(source, width: width, height: height)
+    }
+    
+    func loadMediaFileForSource(_ source: MediaSourceProxy, filename: String?) async throws -> MediaFileHandleProxy {
+        try await mediaLoader.loadMediaFileForSource(source, filename: filename)
+    }
+}
+
 private class ClientDelegateWrapper: ClientDelegate {
     private let authErrorCallback: (Bool) -> Void
     

ElementX/Sources/Services/Client/ClientProxyProtocol.swift

@@ -73,7 +73,7 @@ enum TimelineMediaVisibility: Decodable {
 }
 
 // sourcery: AutoMockable
-protocol ClientProxyProtocol: AnyObject {
+protocol ClientProxyProtocol: AnyObject, MediaLoaderProtocol {
     var actionsPublisher: AnyPublisher<ClientProxyAction, Never> { get }
     
     var loadingStatePublisher: CurrentValuePublisher<ClientProxyLoadingState, Never> { get }
@@ -103,8 +103,6 @@ protocol ClientProxyProtocol: AnyObject {
     
     var pusherNotificationClientIdentifier: String? { get }
     
-    var mediaLoader: MediaLoaderProtocol { get }
-    
     var roomSummaryProvider: RoomSummaryProviderProtocol { get }
     
     /// Used for listing rooms that shouldn't be affected by the main `roomSummaryProvider` filtering

ElementX/Sources/Services/Media/Provider/MediaLoader.swift

@@ -16,17 +16,7 @@ private final class MediaRequest {
 }
 
 actor MediaLoader: MediaLoaderProtocol {
-    // Something is holding onto our MediaProvider (and therefore this MediaLoader) which means
-    // when attempting to clear the caches, the SDK's Client hangs around and we end up with 2.
-    // I have spent a long time trying to understand what's going on – there's instances of both
-    // TimelineViewModel.Context and ComposerToolbarViewModel.Context still hanging around and
-    // a closure captures the media provider from both of those as far as I can tell, but I was
-    // unable to break the reference. Possibly related to the ElementTextView too.
-    //
-    // In lieu of the real fix, lets use a weak reference to the Client here so that it can be
-    // released and hopefully that will solve our logs files exploding in size when encountering
-    // a corrupt/missing database file.
-    private weak var client: ClientProtocol?
+    private let client: ClientProtocol
     private var ongoingRequests = [MediaSourceProxy: MediaRequest]()
 
     init(client: ClientProtocol) {
@@ -34,21 +24,18 @@ actor MediaLoader: MediaLoaderProtocol {
     }
     
     func loadMediaContentForSource(_ source: MediaSourceProxy) async throws -> Data {
-        try await enqueueLoadMediaRequest(forSource: source) { [weak client] in
-            guard let client else { throw MediaLoaderError.missingClient }
-            return try await client.getMediaContent(mediaSource: source.underlyingSource)
+        try await enqueueLoadMediaRequest(forSource: source) {
+            try await self.client.getMediaContent(mediaSource: source.underlyingSource)
         }
     }
     
     func loadMediaThumbnailForSource(_ source: MediaSourceProxy, width: UInt, height: UInt) async throws -> Data {
-        try await enqueueLoadMediaRequest(forSource: source) { [weak client] in
-            guard let client else { throw MediaLoaderError.missingClient }
-            return try await client.getMediaThumbnail(mediaSource: source.underlyingSource, width: UInt64(width), height: UInt64(height))
+        try await enqueueLoadMediaRequest(forSource: source) {
+            try await self.client.getMediaThumbnail(mediaSource: source.underlyingSource, width: UInt64(width), height: UInt64(height))
         }
     }
     
     func loadMediaFileForSource(_ source: MediaSourceProxy, filename: String?) async throws -> MediaFileHandleProxy {
-        guard let client else { throw MediaLoaderError.missingClient }
         let result = try await client.getMediaFile(mediaSource: source.underlyingSource,
                                                    filename: filename,
                                                    mimeType: source.mimeType ?? "application/octet-stream",

ElementX/Sources/Services/Media/Provider/MediaLoaderProtocol.swift

@@ -7,10 +7,6 @@
 
 import Foundation
 
-enum MediaLoaderError: Error {
-    case missingClient
-}
-
 // sourcery: AutoMockable
 protocol MediaLoaderProtocol {
     func loadMediaContentForSource(_ source: MediaSourceProxy) async throws -> Data

ElementX/Sources/Services/Media/Provider/MediaProvider.swift

@@ -9,7 +9,7 @@ import Combine
 import Kingfisher
 import UIKit
 
-struct MediaProvider: MediaProviderProtocol {
+class MediaProvider: MediaProviderProtocol {
     private let mediaLoader: MediaLoaderProtocol
     private let imageCache: Kingfisher.ImageCache
     private let networkMonitor: NetworkMonitorProtocol?

ElementX/Sources/Services/Media/Provider/MediaProviderProtocol.swift

@@ -17,7 +17,7 @@ enum MediaProviderError: Error {
 }
 
 // sourcery: AutoMockable
-protocol MediaProviderProtocol {
+protocol MediaProviderProtocol: AnyObject {
     func imageFromSource(_ source: MediaSourceProxy?, size: CGSize?) -> UIImage?
     func loadImageFromSource(_ source: MediaSourceProxy, size: CGSize?) async -> Result<UIImage, MediaProviderError>
     func loadImageDataFromSource(_ source: MediaSourceProxy) async -> Result<Data, MediaProviderError>

ElementX/Sources/Services/UserSession/UserSessionStore.swift

@@ -94,7 +94,7 @@ class UserSessionStore: UserSessionStoreProtocol {
     // MARK: - Private
     
     private func buildUserSessionWithClient(_ clientProxy: ClientProxyProtocol) -> UserSessionProtocol {
-        let mediaProvider = MediaProvider(mediaLoader: clientProxy.mediaLoader,
+        let mediaProvider = MediaProvider(mediaLoader: clientProxy,
                                           imageCache: .onlyInMemory,
                                           networkMonitor: networkMonitor)