import 'dart:convert';

import 'package:http/http.dart' as http;

import '../models/appconfig.dart';
import 'ai_service.dart';

class DeapsoundAIService implements AiService {
  late final String baseUrl;
  late final String apiKey;
  late final String model;

  DeapsoundAIService() {
    apiKey = AppConfig.env('OPENAI_API_KEY') ?? '';
    baseUrl = AppConfig.env('OPENAI_BASE_URL') ?? '';
    model = AppConfig.env('OPENAI_MODEL') ?? '';
  }

  @override
  Future<String> sendMessage({
    required List<Map<String, String>> messages,
    String? systemPrompt,
    String? userProperties,
  }) async {
    final url = Uri.parse(baseUrl);

    final headers = {
      'Content-Type': 'application/json',
      'Authorization': 'Bearer $apiKey',
    };

    final requestBody = {
      "model": model,
      "messages": messages,
    };

    try {
      final response = await http.post(
        url,
        headers: headers,
        body: jsonEncode(requestBody),
      );
      if (response.statusCode != 200) {
        throw Exception('Unknown error');
      }

      final result = jsonDecode(response.body);

      return result['choices'].first['message']['content'];
    } catch (e) {
      throw Exception('Unknown error');
    }
  }

  @override
  Stream sendMessageStream({
    required List<Map<String, String>> messages,
    String? systemPrompt,
    String? userProperties,
  }) async* {
    final client = http.Client();
    final url = Uri.parse(baseUrl);

    final headers = {
      'Content-Type': 'application/json',
      'Authorization': 'Bearer $apiKey',
    };

    final requestBody = {
      "model": model,
      "messages": messages,
      "stream": true,
    };

    try {
      final request = http.Request('POST', url)
        ..headers.addAll(headers)
        ..body = jsonEncode(requestBody);
      final response = await client.send(request);

      await for (final chunk in response.stream
          .transform(utf8.decoder)
          .transform(const LineSplitter())) {
        if (chunk.isEmpty) continue;

        if (chunk.startsWith('data:')) {
          final jsonStr = chunk.substring(5).trim();
          if (jsonStr == '[DONE]') {
            break;
          }

          final data = jsonDecode(jsonStr);
          final content = data['choices'][0]['delta']['content'] ?? '';
          if (content.isNotEmpty) {
            yield content;
          }
        }
      }
    } catch (e) {
      throw Exception('Unknown error');
    } finally {
      client.close();
    }
  }
}