import 'dart:convert';
import 'package:http/http.dart' as http;
import '../http_client.dart';
import '../http_util.dart';
import '../models.dart';
import 'base_provider.dart';

/// Faithful port of `g4f.Provider.Yqcloud`.
class Yqcloud extends BaseProvider {
  @override
  String get name => 'Yqcloud';

  @override
  String get url => 'https://chat9.yqcloud.top';

  @override
  bool get working => true;

  @override
  List<String> get models => const ['gpt-4'];

  @override
  String get defaultModel => 'gpt-4';

  @override
  Map<String, String> get modelAliases => const {
        G4FModels.gpt4o: 'gpt-4',
        G4FModels.gpt4oMini: 'gpt-4',
      };

  static const _endpoint = 'https://api.binjie.fun/api/generateStream';

  @override
  Stream<String> createAsyncGenerator(
    String model,
    List<Message> messages, {
    bool stream = false,
  }) async* {
    final systemMessage = extractSystemMessage(messages);
    final history = [
      for (final m in messages)
        if (m.role != Role.system) m,
    ];
    final prompt = formatPrompt(history, includeSystem: false);
    final userId = '#/chat/${DateTime.now().millisecondsSinceEpoch}';

    final req = http.Request('POST', Uri.parse(_endpoint));
    req.headers.addAll({
      'accept': 'application/json, text/plain, */*',
      'accept-language': 'en-US,en;q=0.9',
      'content-type': 'application/json',
      'origin': url,
      'referer': '$url/',
      'user-agent': kDesktopUserAgent,
    });
    req.body = jsonEncode({
      'prompt': prompt,
      'userId': userId,
      'network': true,
      'system': systemMessage,
      'withoutContext': false,
      'stream': true,
    });

    final response = await g4fHttp.send(req).timeout(requestTimeout);
    if (response.statusCode != 200) {
      final err = await response.stream.bytesToString();
      throw Exception('$name returned ${response.statusCode}: $err');
    }
    final fullText = utf8.decode(await response.stream.toBytes()).trim();
    if (!looksLikeModelOutput(fullText) || fullText.contains('Error:')) {
      throw Exception('$name unusable body');
    }
    yield fullText;
  }
}