import 'dart:typed_data';

import 'package:dio/dio.dart';
import 'package:social_app/core/chat/chat_api.dart';
import 'package:social_app/data/network/i_api_client.dart';

class ChatApiImpl implements ChatApi {
  ChatApiImpl(this._apiClient);

  final IApiClient _apiClient;

  @override
  Future<Map<String, dynamic>> createRun(Map<String, dynamic> runInput) async {
    final response = await _apiClient.post<Map<String, dynamic>>(
      '/api/v1/agent/runs',
      data: runInput,
    );
    final payload = response.data;
    if (payload is! Map<String, dynamic>) {
      throw StateError('Invalid /agent/runs response');
    }
    return payload;
  }

  @override
  Future<Stream<String>> streamRunEvents(
    String threadId, {
    required String runId,
    String? lastEventId,
  }) {
    final headers = <String, String>{'Accept': 'text/event-stream'};
    if (lastEventId != null && lastEventId.isNotEmpty) {
      headers['Last-Event-ID'] = lastEventId;
    }
    final encodedRunId = Uri.encodeQueryComponent(runId);
    final path = '/api/v1/agent/runs/$threadId/events?runId=$encodedRunId';
    return _apiClient.getSseLines(path, headers: headers);
  }

  @override
  Future<Map<String, dynamic>> fetchHistory({
    String? threadId,
    DateTime? beforeDate,
  }) async {
    final path = _buildHistoryPath(threadId: threadId, beforeDate: beforeDate);
    final response = await _apiClient.get<Map<String, dynamic>>(path);
    final payload = response.data;
    if (payload is! Map<String, dynamic>) {
      throw StateError('Invalid /agent/history response');
    }
    return payload;
  }

  @override
  Future<Map<String, dynamic>> uploadAttachment({
    required String threadId,
    required String filename,
    required String mimeType,
    required Uint8List bytes,
  }) async {
    final formData = FormData.fromMap({
      'threadId': threadId,
      'file': MultipartFile.fromBytes(
        bytes,
        filename: filename,
        contentType: DioMediaType.parse(mimeType),
      ),
    });
    final response = await _apiClient.post<Map<String, dynamic>>(
      '/api/v1/agent/attachments',
      data: formData,
    );
    final payload = response.data;
    if (payload is! Map<String, dynamic>) {
      throw StateError('Invalid /agent/attachments response');
    }
    return payload;
  }

  @override
  Future<Uint8List> fetchAttachmentPreview(String previewPath) async {
    final response = await _apiClient.get<List<int>>(
      previewPath,
      options: Options(responseType: ResponseType.bytes),
    );
    final payload = response.data;
    if (payload is! List<int>) {
      throw StateError('Invalid attachment payload');
    }
    return Uint8List.fromList(payload);
  }

  @override
  Future<String> transcribeAudio(String filePath) async {
    final formData = FormData.fromMap({
      'audio': await MultipartFile.fromFile(
        filePath,
        filename: 'recording.wav',
        contentType: DioMediaType('audio', 'wav'),
      ),
    });
    final response = await _apiClient.post<Map<String, dynamic>>(
      '/api/v1/agent/transcribe',
      data: formData,
    );
    final payload = response.data;
    if (payload is! Map<String, dynamic>) {
      throw StateError('Invalid /agent/transcribe response');
    }
    final transcript = payload['transcript'];
    if (transcript is! String) {
      throw StateError('Missing transcript in /agent/transcribe response');
    }
    return transcript;
  }

  @override
  Future<void> cancelRun({
    required String threadId,
    required String runId,
  }) async {
    final encodedRunId = Uri.encodeQueryComponent(runId);
    await _apiClient.post<Map<String, dynamic>>(
      '/api/v1/agent/runs/$threadId/cancel?runId=$encodedRunId',
    );
  }

  static String _buildHistoryPath({String? threadId, DateTime? beforeDate}) {
    final query = <String>[];
    if (threadId != null && threadId.isNotEmpty) {
      query.add('threadId=${Uri.encodeQueryComponent(threadId)}');
    }
    if (beforeDate != null) {
      final day = DateTime(beforeDate.year, beforeDate.month, beforeDate.day);
      query.add('before=${day.toIso8601String().substring(0, 10)}');
    }
    if (query.isEmpty) {
      return '/api/v1/agent/history';
    }
    return '/api/v1/agent/history?${query.join('&')}';
  }
}