import 'package:dio/dio.dart';

import '../config.dart';
import '../models/api_exception.dart';
import '../models/login_result.dart';
import '../models/support_message.dart';
import '../models/support_ticket.dart';

class SupportApi {
  SupportApi({Dio? dio, String? origin, this.onUnauthorized})
    : dio =
          dio ??
          Dio(
            BaseOptions(
              baseUrl: origin ?? baseUrl,
              connectTimeout: const Duration(seconds: 20),
              receiveTimeout: const Duration(seconds: 20),
              headers: const {
                'Accept': 'application/json',
                'Content-Type': 'application/json',
              },
            ),
          ) {
    this.dio.interceptors.add(
      InterceptorsWrapper(
        onRequest: (options, handler) {
          final token = authToken;
          if (token != null && token.isNotEmpty) {
            options.headers['Authorization'] = 'Bearer $token';
          }
          handler.next(options);
        },
        onError: (error, handler) {
          final apiError = _exceptionFor(error);
          final sentAuth =
              error.requestOptions.headers['Authorization'] != null;
          if (apiError.isUnauthorized && sentAuth) {
            onUnauthorized?.call();
          }
          handler.reject(
            DioException(
              requestOptions: error.requestOptions,
              response: error.response,
              type: error.type,
              error: apiError,
              message: apiError.message,
            ),
          );
        },
      ),
    );
  }

  final Dio dio;
  String? authToken;
  void Function()? onUnauthorized;

  Future<LoginResult> login(String username, String password) {
    return _send(
      dio.post<dynamic>(
        '/api/auth/login',
        data: {'username': username, 'password': password},
      ),
      (data) {
        if (data is! Map) {
          throw const FormatException('Unexpected login payload');
        }
        return LoginResult.fromJson(Map<String, dynamic>.from(data));
      },
    );
  }

  Future<List<SupportTicket>> listTickets({String? status, String? category}) {
    return _send(
      dio.get<dynamic>(
        '/api/support/tickets',
        queryParameters: ticketListQuery(status: status, category: category),
      ),
      (data) {
        if (data is! Map || data['tickets'] is! List) {
          throw const FormatException('Unexpected ticket list');
        }
        return [
          for (final item in data['tickets'] as List)
            if (item is Map)
              SupportTicket.fromJson(Map<String, dynamic>.from(item)),
        ];
      },
    );
  }

  Future<SupportThread> getThread(String ticketId) {
    return _send(dio.get<dynamic>('/api/support/tickets/$ticketId'), _thread);
  }

  Future<SupportThread> reply(String ticketId, String body) {
    return _send(
      dio.post<dynamic>(
        '/api/support/tickets/$ticketId/messages',
        data: {'body': body},
      ),
      _thread,
    );
  }

  Future<SupportThread> setStatus(String ticketId, String status) {
    return _send(
      dio.post<dynamic>(
        '/api/support/tickets/$ticketId/status',
        data: {'status': status},
      ),
      _thread,
    );
  }

  Future<void> registerDevice({
    required String token,
    required String platform,
  }) {
    return _send(
      dio.put<dynamic>(
        '/api/support/devices',
        data: {'token': token, 'platform': platform},
      ),
      (_) {},
    );
  }

  Future<void> unregisterDevice(String token) {
    return _send(
      dio.delete<dynamic>('/api/support/devices', data: {'token': token}),
      (_) {},
    );
  }

  SupportThread _thread(Object? data) {
    if (data is! Map) {
      throw const FormatException('Unexpected thread payload');
    }
    return SupportThread.fromJson(Map<String, dynamic>.from(data));
  }

  Future<T> _send<T>(
    Future<Response<dynamic>> call,
    T Function(Object? data) parse,
  ) async {
    try {
      final response = await call;
      return parse(response.data);
    } on DioException catch (error) {
      final wrapped = error.error;
      if (wrapped is ApiException) {
        throw wrapped;
      }
      throw _exceptionFor(error);
    } on FormatException {
      throw const ApiException(message: 'Unexpected response from the server.');
    }
  }

  ApiException _exceptionFor(DioException error) {
    final offline =
        error.type == DioExceptionType.connectionError ||
        error.type == DioExceptionType.connectionTimeout ||
        error.type == DioExceptionType.receiveTimeout ||
        error.type == DioExceptionType.sendTimeout;
    return ApiException.fromBody(
      statusCode: error.response?.statusCode,
      body: error.response?.data,
      fallback: offline
          ? 'Could not reach the server.'
          : 'Something went wrong.',
    );
  }
}