// Expected API:
//   POST   /api/auth/login                  body: {"token":"..."}  → {"user_id":"..."}
//   GET    /api/channels                    header: Authorization: Bearer TOKEN
//                                           → [{"id":"1","name":"Alpha","member_count":3}]
//   POST   /api/channels/join               body: {"key":"..."}  → {"id":"...","name":"..."}
//   GET    /api/channels/{id}/livekit-token → {"url":"wss://...","token":"eyJ..."}

import 'dart:convert';
import 'package:http/http.dart' as http;
import '../config/app_config.dart';
import '../models/channel.dart';
import 'auth_service.dart';

// ── LiveKit credentials model ─────────────────────────────────────────────
class LivekitCredentials {
  final String url;
  final String token;
  const LivekitCredentials({required this.url, required this.token});
}

// ── Fake data (only used when AppConfig.debug == true) ────────────────────
const _fakeChannels = [
  {'id': '1', 'name': 'تیم آلفا', 'member_count': 4},
  {'id': '2', 'name': 'پشتیبانی میدانی', 'member_count': 2},
  {'id': '3', 'name': 'فرماندهی', 'member_count': 7},
  {'id': '4', 'name': 'گروه لجستیک', 'member_count': 3},
  {'id': '5', 'name': 'واحد امنیت', 'member_count': 5},
];
// ─────────────────────────────────────────────────────────────────────────

class ApiService {
  final AuthService _auth;

  ApiService(this._auth);

  Future<Map<String, String>> _headers() async {
    final token = await _auth.getToken();
    return {
      'Content-Type': 'application/json',
      if (token != null) 'Authorization': 'Bearer $token',
    };
  }

  Future<bool> login(String token) async {
    if (AppConfig.debug) {
      await Future.delayed(const Duration(milliseconds: 600));
      await _auth.saveAuth(token: token, userId: 'debug_user');
      return true;
    }

    try {
      final res = await http
          .post(
            Uri.parse('${AppConfig.baseUrl}/api/auth/login'),
            headers: {'Content-Type': 'application/json'},
            body: jsonEncode({'token': token}),
          )
          .timeout(const Duration(seconds: 10));

      if (res.statusCode == 200) {
        final data = jsonDecode(res.body) as Map<String, dynamic>;
        await _auth.saveAuth(
          token: token,
          userId: data['user_id']?.toString(),
        );
        return true;
      }
      return false;
    } catch (_) {
      return false;
    }
  }

  Future<List<Channel>> getChannels() async {
    if (AppConfig.debug) {
      await Future.delayed(const Duration(milliseconds: 500));
      return _fakeChannels
          .map((e) => Channel.fromJson(e as Map<String, dynamic>))
          .toList();
    }

    try {
      final res = await http
          .get(
            Uri.parse('${AppConfig.baseUrl}/api/channels'),
            headers: await _headers(),
          )
          .timeout(const Duration(seconds: 10));

      if (res.statusCode == 200) {
        final list = jsonDecode(res.body) as List;
        return list
            .map((e) => Channel.fromJson(e as Map<String, dynamic>))
            .toList();
      }
      return [];
    } catch (_) {
      return [];
    }
  }

  Future<Channel?> joinPrivateChannel(String key) async {
    if (AppConfig.debug) {
      await Future.delayed(const Duration(milliseconds: 700));
      // کلید صحیح در حالت دیباگ: هر چیزی غیر از "wrong"
      if (key.toLowerCase() == 'wrong') return null;
      return Channel(
        id: 'private_${key.hashCode}',
        name: 'کانال خصوصی ($key)',
        memberCount: 1,
      );
    }

    try {
      final res = await http
          .post(
            Uri.parse('${AppConfig.baseUrl}/api/channels/join'),
            headers: await _headers(),
            body: jsonEncode({'key': key}),
          )
          .timeout(const Duration(seconds: 10));

      if (res.statusCode == 200) {
        return Channel.fromJson(
            jsonDecode(res.body) as Map<String, dynamic>);
      }
      return null;
    } catch (_) {
      return null;
    }
  }

  Future<LivekitCredentials?> getLivekitToken(String channelId) async {
    if (AppConfig.debug) {
      await Future.delayed(const Duration(milliseconds: 300));
      return const LivekitCredentials(
        url: 'wss://fake.livekit.io',
        token: 'debug_livekit_token',
      );
    }

    try {
      final res = await http
          .get(
            Uri.parse(
                '${AppConfig.baseUrl}/api/channels/$channelId/livekit-token'),
            headers: await _headers(),
          )
          .timeout(const Duration(seconds: 10));

      if (res.statusCode == 200) {
        final data = jsonDecode(res.body) as Map<String, dynamic>;
        return LivekitCredentials(
          url: data['url'] as String,
          token: data['token'] as String,
        );
      }
      return null;
    } catch (_) {
      return null;
    }
  }
}