Merge commit '7621e2f8dec938cf48181c8b10afc9b01f444e68' into beta

submodules/Speak/Sources/Speak.swift

@@ -0,0 +1,59 @@
+import Foundation
+import AVFoundation
+import AccountContext
+
+// Incuding at least one Objective-C class in a swift file ensures that it doesn't get stripped by the linker
+private final class LinkHelperClass: NSObject {
+}
+
+public class SpeechSynthesizerHolder: NSObject, AVSpeechSynthesizerDelegate {
+    private var speechSynthesizer: AVSpeechSynthesizer
+    
+    public var completion: () -> Void = {}
+    
+    init(speechSynthesizer: AVSpeechSynthesizer) {
+        self.speechSynthesizer = speechSynthesizer
+        
+        super.init()
+        
+        self.speechSynthesizer.delegate = self
+    }
+    
+    deinit {
+        self.stop()
+    }
+    
+    public func stop() {
+        self.speechSynthesizer.stopSpeaking(at: .immediate)
+    }
+    
+    public func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance: AVSpeechUtterance) {
+        self.completion()
+    }
+}
+
+public func supportedSpeakLanguages() -> Set<String> {
+    var languages: [String] = []
+    for voice in AVSpeechSynthesisVoice.speechVoices() {
+        let components = voice.language.components(separatedBy: "-")
+        if let language = components.first {
+            languages.append(language)
+        }
+    }
+    return Set(languages)
+}
+
+public func speakText(context: AccountContext, text: String) -> SpeechSynthesizerHolder? {
+    guard !text.isEmpty else {
+        return nil
+    }
+    
+    let speechSynthesizer = AVSpeechSynthesizer()
+    let utterance = AVSpeechUtterance(string: text)
+    if #available(iOS 11.0, *), let language = NSLinguisticTagger.dominantLanguage(for: text) {
+        utterance.voice = AVSpeechSynthesisVoice(language: language)
+    }
+    speechSynthesizer.speak(utterance)
+    
+    return SpeechSynthesizerHolder(speechSynthesizer: speechSynthesizer)
+}