import 'dart:async';
import 'dart:typed_data';

import 'package:sparkchain/sparkchain.dart';

import '../../core/utils/logger.dart';
import '../models/appconfig.dart';

/// 端上讯飞翻译。没配密钥就返回 null，调用方继续走原来的服务端翻译。
class SparkChainSession {
  SparkChainSession._();

  static const _tag = 'SparkChain';
  static bool _ready = false;
  static bool _eventsAttached = false;
  static bool listening = false;
  static int _seq = 0;
  static final Map<String, Completer<Map<String, dynamic>>> _waiters = {};
  static final Map<String, void Function(Uint8List pcm, bool isFinal)> _ttsHandlers = {};
  static final Map<String, Completer<void>> _ttsWaiters = {};

  /// 听写结果。只在 [startListen] 成功之后、[stopListen] 之前有意义。
  static void Function(Map<String, dynamic> event)? asrListener;

  static Future<bool> ensure() async {
    if (_ready) return true;
    final appId = AppConfig.cred('sparkchain', 'app_id', 'SPARKCHAIN_APP_ID');
    final apiKey = AppConfig.cred('sparkchain', 'api_key', 'SPARKCHAIN_API_KEY');
    final apiSecret =
        AppConfig.cred('sparkchain', 'api_secret', 'SPARKCHAIN_API_SECRET');
    if (appId == null || apiKey == null || apiSecret == null) {
      return false;
    }
    if (!_eventsAttached) {
      _eventsAttached = true;
      SparkChain.events.listen(_onEvent);
    }
    final apiType =
        int.tryParse(AppConfig.cred('sparkchain', 'api_type', 'SPARKCHAIN_API_TYPE') ?? '') ??
            1;
    final code = await SparkChain.init(
      appId: appId,
      apiKey: apiKey,
      apiSecret: apiSecret,
      apiType: apiType,
    );
    Logger.i(_tag, 'init code=$code apiType=$apiType');
    _ready = code == 0;
    return _ready;
  }

  static void _onEvent(Map<String, dynamic> event) {
    final id = event['id']?.toString() ?? '';
    final kind = event['kind'];
    if (kind == 'its' || (kind == 'error' && event['where'] == 'its')) {
      final waiter = _waiters[id];
      if (waiter != null && !waiter.isCompleted) waiter.complete(event);
    }
    if (kind == 'asr' || (kind == 'error' && event['where'] == 'asr')) {
      asrListener?.call(event);
    }
    if (kind == 'tts' || (kind == 'error' && event['where'] == 'tts')) {
      _onTts(id, event);
    }
  }

  static void _onTts(String id, Map<String, dynamic> event) {
    if (event['kind'] == 'error') {
      _ttsHandlers.remove(id);
      final waiter = _ttsWaiters.remove(id);
      if (waiter != null && !waiter.isCompleted) {
        waiter.completeError(StateError('${event['code']}'));
      }
      return;
    }
    final raw = event['pcm'];
    final pcm = raw is Uint8List ? raw : Uint8List(0);
    _ttsHandlers[id]?.call(pcm, event['final'] == true);
    if (event['final'] == true) {
      _ttsHandlers.remove(id);
      final waiter = _ttsWaiters.remove(id);
      if (waiter != null && !waiter.isCompleted) waiter.complete();
    }
  }

  /// 只听 [lang] 这一种。ga 走实时转写，其余走听写。SDK 不自己开麦。
  static Future<bool> startListen(String lang) async {
    if (!await ensure()) return false;
    final code = await SparkChain.startListen(id: 'listen', lang: sparkChainShortCode(lang));
    listening = code == 0;
    if (!listening) {
      Logger.w(_tag, 'startListen 失败 code=$code');
    }
    return listening;
  }

  static void write(Uint8List pcm) {
    if (!listening || pcm.isEmpty) return;
    unawaited(SparkChain.write(pcm));
  }

  static Future<void> stopListen() async {
    if (!listening) return;
    listening = false;
    asrListener = null;
    try {
      await SparkChain.stopListen();
    } catch (e) {
      Logger.w(_tag, 'stopListen: $e');
    }
  }

  /// 合成一段。PCM 按到达顺序交给 [onPcm]，整段结束或失败才返回。
  static Future<void> speak({
    required String lang,
    required String text,
    required void Function(Uint8List pcm, bool isFinal) onPcm,
  }) async {
    if (!await ensure()) {
      throw StateError('sparkchain not ready');
    }
    final id = 'tts-${++_seq}';
    final waiter = Completer<void>();
    _ttsWaiters[id] = waiter;
    _ttsHandlers[id] = onPcm;
    final code = await SparkChain.speak(
      id: id,
      lang: sparkChainShortCode(lang),
      text: text,
    );
    if (code != 0) {
      _ttsHandlers.remove(id);
      _ttsWaiters.remove(id);
      throw StateError('speak $code');
    }
    await waiter.future.timeout(const Duration(seconds: 20));
  }

  /// 短码 zh / en / ga。失败返回 null，不抛。
  static Future<String?> translate({
    required String from,
    required String to,
    required String text,
  }) async {
    if (!await ensure()) return null;
    final id = '${++_seq}';
    final waiter = Completer<Map<String, dynamic>>();
    _waiters[id] = waiter;
    try {
      final code = await SparkChain.translate(
        id: id,
        from: sparkChainShortCode(from),
        to: sparkChainShortCode(to),
        text: text,
      );
      if (code != 0) {
        Logger.w(_tag, 'translate 启动失败 code=$code');
        return null;
      }
      final event = await waiter.future.timeout(const Duration(seconds: 12));
      if (event['kind'] != 'its') {
        Logger.w(_tag, 'translate 失败 code=${event['code']} sid=${event['sid']}');
        return null;
      }
      final out = (event['text'] as String?)?.trim() ?? '';
      return out.isEmpty ? null : out;
    } on TimeoutException {
      Logger.w(_tag, 'translate 超时');
      return null;
    } finally {
      _waiters.remove(id);
    }
  }
}