chore: vendor swabble and add speech usage strings

2025-12-06 02:10:20 +01:00
parent 4e7d905783
commit e1c9885566
34 changed files with 1577 additions and 1 deletions
--- a/Swabble/Sources/SwabbleCore/Speech/SpeechPipeline.swift
+++ b/Swabble/Sources/SwabbleCore/Speech/SpeechPipeline.swift
@@ -0,0 +1,111 @@
+import AVFoundation
+import Foundation
+import Speech
+
+public struct SpeechSegment: Sendable {
+    public let text: String
+    public let isFinal: Bool
+}
+
+public enum SpeechPipelineError: Error {
+    case authorizationDenied
+    case analyzerFormatUnavailable
+    case transcriberUnavailable
+}
+
+/// Live microphone → SpeechAnalyzer → SpeechTranscriber pipeline.
+public actor SpeechPipeline {
+    private struct UnsafeBuffer: @unchecked Sendable { let buffer: AVAudioPCMBuffer }
+
+    private var engine = AVAudioEngine()
+    private var transcriber: SpeechTranscriber?
+    private var analyzer: SpeechAnalyzer?
+    private var inputContinuation: AsyncStream<AnalyzerInput>.Continuation?
+    private var resultTask: Task<Void, Never>?
+    private let converter = BufferConverter()
+
+    public init() {}
+
+    public func start(localeIdentifier: String, etiquette: Bool) async throws -> AsyncStream<SpeechSegment> {
+        let auth = await requestAuthorizationIfNeeded()
+        guard auth == .authorized else { throw SpeechPipelineError.authorizationDenied }
+
+        let transcriberModule = SpeechTranscriber(
+            locale: Locale(identifier: localeIdentifier),
+            transcriptionOptions: etiquette ? [.etiquetteReplacements] : [],
+            reportingOptions: [.volatileResults],
+            attributeOptions: [])
+        self.transcriber = transcriberModule
+
+        guard let analyzerFormat = await SpeechAnalyzer.bestAvailableAudioFormat(compatibleWith: [transcriberModule])
+        else {
+            throw SpeechPipelineError.analyzerFormatUnavailable
+        }
+
+        self.analyzer = SpeechAnalyzer(modules: [transcriberModule])
+        let (stream, continuation) = AsyncStream<AnalyzerInput>.makeStream()
+        self.inputContinuation = continuation
+
+        let inputNode = self.engine.inputNode
+        let inputFormat = inputNode.outputFormat(forBus: 0)
+        inputNode.removeTap(onBus: 0)
+        inputNode.installTap(onBus: 0, bufferSize: 2048, format: inputFormat) { [weak self] buffer, _ in
+            guard let self else { return }
+            let boxed = UnsafeBuffer(buffer: buffer)
+            Task { await self.handleBuffer(boxed.buffer, targetFormat: analyzerFormat) }
+        }
+
+        self.engine.prepare()
+        try self.engine.start()
+        try await self.analyzer?.start(inputSequence: stream)
+
+        guard let transcriberForStream = self.transcriber else {
+            throw SpeechPipelineError.transcriberUnavailable
+        }
+
+        return AsyncStream { continuation in
+            self.resultTask = Task {
+                do {
+                    for try await result in transcriberForStream.results {
+                        let seg = SpeechSegment(text: String(result.text.characters), isFinal: result.isFinal)
+                        continuation.yield(seg)
+                    }
+                } catch {
+                    // swallow errors and finish
+                }
+                continuation.finish()
+            }
+            continuation.onTermination = { _ in
+                Task { await self.stop() }
+            }
+        }
+    }
+
+    public func stop() async {
+        self.resultTask?.cancel()
+        self.inputContinuation?.finish()
+        self.engine.inputNode.removeTap(onBus: 0)
+        self.engine.stop()
+        try? await self.analyzer?.finalizeAndFinishThroughEndOfInput()
+    }
+
+    private func handleBuffer(_ buffer: AVAudioPCMBuffer, targetFormat: AVAudioFormat) async {
+        do {
+            let converted = try converter.convert(buffer, to: targetFormat)
+            let input = AnalyzerInput(buffer: converted)
+            self.inputContinuation?.yield(input)
+        } catch {
+            // drop on conversion failure
+        }
+    }
+
+    private func requestAuthorizationIfNeeded() async -> SFSpeechRecognizerAuthorizationStatus {
+        let current = SFSpeechRecognizer.authorizationStatus()
+        guard current == .notDetermined else { return current }
+        return await withCheckedContinuation { continuation in
+            SFSpeechRecognizer.requestAuthorization { status in
+                continuation.resume(returning: status)
+            }
+        }
+    }
+}