import 'dart:async';

import 'package:flutter/services.dart';

/// 讯飞 SparkChain。事件从 [events] 来，方法调用只返回启动码。
class SparkChain {
  static const _method = MethodChannel('sparkchain');
  static const _events = EventChannel('sparkchain/events');

  static Stream<Map<String, dynamic>>? _stream;

  static Stream<Map<String, dynamic>> get events {
    _stream ??= _events.receiveBroadcastStream().map((event) {
      final raw = Map<Object?, Object?>.from(event as Map);
      return raw.map((key, value) => MapEntry(key.toString(), value));
    });
    return _stream!;
  }

  /// 0 成功。不打印密钥。
  static Future<int> init({
    required String appId,
    required String apiKey,
    required String apiSecret,
    int apiType = 1,
  }) async {
    final code = await _method.invokeMethod<int>('init', {
      'appId': appId,
      'apiKey': apiKey,
      'apiSecret': apiSecret,
      'apiType': apiType,
    });
    return code ?? -1;
  }

  static Future<int> translate({
    required String id,
    required String from,
    required String to,
    required String text,
  }) async {
    final code = await _method.invokeMethod<int>('translate', {
      'id': id,
      'from': from,
      'to': to,
      'text': text,
    });
    return code ?? -1;
  }

  static Future<int> speak({
    required String id,
    required String lang,
    required String text,
    String? voice,
  }) async {
    final code = await _method.invokeMethod<int>('speak', {
      'id': id,
      'lang': lang,
      'text': text,
      if (voice != null) 'voice': voice,
    });
    return code ?? -1;
  }

  /// [lang] 用短码 zh / en / ga。ga 走实时转写，其余走听写。
  static Future<int> startListen({
    required String id,
    required String lang,
  }) async {
    final code = await _method.invokeMethod<int>('startListen', {
      'id': id,
      'lang': lang,
    });
    return code ?? -1;
  }

  static Future<int> write(Uint8List pcm) async {
    final code = await _method.invokeMethod<int>('write', {'pcm': pcm});
    return code ?? -1;
  }

  static Future<void> stopListen() async {
    await _method.invokeMethod<int>('stopListen');
  }
}

/// 把界面上的 BCP-47 收成插件认的短码。不认识的原样返回，让原生按失败处理。
String sparkChainShortCode(String code) {
  final raw = code.trim().toLowerCase().replaceAll('_', '-');
  if (raw.isEmpty) return raw;
  if (raw == 'ga' || raw.startsWith('ga-')) return 'ga';
  if (raw == 'zh' || raw.startsWith('zh-')) return 'zh';
  if (raw == 'en' || raw.startsWith('en-')) return 'en';
  final dash = raw.indexOf('-');
  return dash < 0 ? raw : raw.substring(0, dash);
}