Add voice message playback from the timeline (#1844)

ElementX/Sources/Services/VoiceMessage/VoiceMessageMediaManager.swift

@@ -0,0 +1,67 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+enum VoiceMessageMediaManagerError: Error {
+    case unsupportedMimeTye
+}
+
+class VoiceMessageMediaManager: VoiceMessageMediaManagerProtocol {
+    private let mediaProvider: MediaProviderProtocol
+    private let cache: VoiceMessageCache
+
+    private let supportedVoiceMessageMimeType = "audio/ogg"
+
+    /// Preferred audio file extension after conversion
+    private let preferredAudioExtension = "m4a"
+
+    init(mediaProvider: MediaProviderProtocol) {
+        self.mediaProvider = mediaProvider
+        cache = VoiceMessageCache()
+    }
+    
+    deinit {
+        cache.clearCache()
+    }
+    
+    func loadVoiceMessageFromSource(_ source: MediaSourceProxy, body: String?) async throws -> URL {
+        guard let mimeType = source.mimeType, mimeType == supportedVoiceMessageMimeType else {
+            throw VoiceMessageMediaManagerError.unsupportedMimeTye
+        }
+        
+        // Do we already have a converted version?
+        if let fileURL = cache.fileURL(for: source, withExtension: preferredAudioExtension) {
+            return fileURL
+        }
+        
+        // Otherwise, load the file from source
+        guard case .success(let fileHandle) = await mediaProvider.loadFileFromSource(source, body: body) else {
+            throw MediaProviderError.failedRetrievingFile
+        }
+        let fileURL = try cache.cache(mediaSource: source, using: fileHandle.url)
+                
+        // Convert from ogg
+        let audioConverter = AudioConverter()
+        let convertedFileURL = cache.cacheURL(for: source, replacingExtension: preferredAudioExtension)
+        try audioConverter.convertToMPEG4AAC(sourceURL: fileURL, destinationURL: convertedFileURL)
+        
+        // we don't need the original file anymore
+        try? FileManager.default.removeItem(at: fileURL)
+        
+        return convertedFileURL
+    }
+}