FabledApp/lib/data/api/voice_api.dart

import 'dart:typed_data';

import 'package:dio/dio.dart';

import 'api_client.dart';

class VoiceStatus {
  final bool enabled;
  final bool stt;
  final bool tts;

  const VoiceStatus({
    required this.enabled,
    required this.stt,
    required this.tts,
  });

  /// True when voice is enabled and at least STT is ready.
  /// TTS is optional — voice mode works without it (STT-only).
  bool get fullyAvailable => enabled && stt;

  factory VoiceStatus.fromJson(Map<String, dynamic> json) => VoiceStatus(
        enabled: json['enabled'] as bool? ?? false,
        stt: json['stt'] as bool? ?? false,
        tts: json['tts'] as bool? ?? false,
      );
}

class VoiceApi {
  final Dio _dio;
  const VoiceApi(this._dio);

  /// Check whether voice features are available on this server.
  Future<VoiceStatus> checkStatus() async {
    try {
      final response = await _dio.get('/api/voice/status');
      return VoiceStatus.fromJson(response.data as Map<String, dynamic>);
    } on DioException catch (e) {
      throw dioToApp(e);
    }
  }

  /// POST WebM/Opus audio bytes and return the transcript string.
  /// [context] is optional recent conversation text passed as initial_prompt
  /// to Whisper, reducing mishearings of domain-specific words.
  /// Returns empty string on empty or error response.
  Future<String> transcribe(Uint8List audioBytes, {String? context}) async {
    try {
      final fields = <String, dynamic>{
        'audio': MultipartFile.fromBytes(
          audioBytes,
          filename: 'audio.m4a',
          contentType: DioMediaType('audio', 'mp4'),
        ),
        if (context != null && context.isNotEmpty) 'context': context,
      };
      final formData = FormData.fromMap(fields);
      final response = await _dio.post(
        '/api/voice/transcribe',
        data: formData,
        options: Options(
          receiveTimeout: const Duration(seconds: 60),
          contentType: 'multipart/form-data',
        ),
      );
      final data = response.data as Map<String, dynamic>;
      return (data['transcript'] as String? ?? '').trim();
    } on DioException catch (e) {
      throw dioToApp(e);
    }
  }

  /// POST text and return raw WAV bytes.
  Future<Uint8List> synthesise(String text) async {
    try {
      final response = await _dio.post(
        '/api/voice/synthesise',
        data: {'text': text},
        options: Options(responseType: ResponseType.bytes),
      );
      return Uint8List.fromList(response.data as List<int>);
    } on DioException catch (e) {
      throw dioToApp(e);
    }
  }
}