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

class AiChatOs extends BaseProvider {
  @override
  String get name => 'AiChatOs';

  @override
  bool get working => true;

  @override
  List<String> get models => [G4FModels.gpt4];

  @override
  String get defaultModel => G4FModels.gpt4;

  @override
  Stream<String> createAsyncGenerator(
    String model,
    List<Message> messages, {
    bool stream = false,
  }) async* {
    final url = Uri.parse('https://api.aichatos.cloud/api/generateStream');
    final userId = '#/chat/${DateTime.now().millisecondsSinceEpoch}';

    final systemMessage = extractSystemMessage(messages);
    final formattedPrompt = formatPrompt(messages);

    final req = http.Request('POST', url);
    req.headers.addAll({
      'Content-Type': 'application/json',
      'Origin': 'https://chat.aichatos.top',
      'Referer': 'https://chat.aichatos.top/',
      'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36',
    });

    req.body = jsonEncode({
      'prompt': formattedPrompt,
      'userId': userId,
      'network': true,
      'system': systemMessage,
      'withoutContext': false,
      'stream': stream,
    });

    final response = await g4fHttp.send(req);

    if (response.statusCode == 200) {
      final resBytes = await response.stream.toBytes();
      final fullText = utf8.decode(resBytes).trim();
      if (fullText.isNotEmpty && !fullText.startsWith('<!DOCTYPE') && !fullText.contains('Error:')) {
        yield fullText;
      } else {
        throw Exception('$name unusable body');
      }
    } else {
      throw Exception('$name returned status ${response.statusCode}');
    }
  }
}