import 'dart:convert';

import 'package:media_kit/media_kit.dart';

import '../core/constants/storage_keys.dart';
import '../core/utils/app_logger.dart';
import 'host_mapping_proxy_service.dart';
import 'server_service.dart';
import 'storage_service.dart';

class CustomLineService {
  CustomLineService._();

  static final CustomLineService instance = CustomLineService._();

  HostMappingProxyEndpoint? get currentProxyEndpoint =>
      HostMappingProxyService.instance.endpoint;

  Future<SelectedCustomLineNode?> getSelectedNode() async {
    final raw = await StorageService.instance.getString(
      StorageKeys.selectedCustomLineNode,
    );
    if (raw == null || raw.isEmpty) return null;

    try {
      final decoded = jsonDecode(raw);
      if (decoded is! Map<String, dynamic>) return null;
      final node = SelectedCustomLineNode.fromJson(decoded);
      if (!node.canRewriteDownloadUrl) return null;
      return node;
    } catch (_) {
      return null;
    }
  }

  Future<void> setSelectedNode(SelectedCustomLineNode node) async {
    if (!node.canRewriteDownloadUrl) {
      throw ArgumentError('The selected custom line node has no usable IP.');
    }
    await StorageService.instance.setString(
      StorageKeys.selectedCustomLineNode,
      jsonEncode(node.toJson()),
    );
  }

  Future<void> clearSelectedNode() async {
    await StorageService.instance.remove(StorageKeys.selectedCustomLineNode);
    await HostMappingProxyService.instance.stop();
  }

  Future<CustomLineDownloadRoute> routeDownloadUrl(String url) async {
    if (!_canUseCustomLine()) {
      await HostMappingProxyService.instance.stop();
      return CustomLineDownloadRoute(url: url);
    }

    final node = await getSelectedNode();
    if (node == null) return CustomLineDownloadRoute(url: url);

    final uri = Uri.tryParse(url);
    if (uri == null || uri.host.isEmpty) {
      return CustomLineDownloadRoute(url: url);
    }

    final endpoint = await activateSelectedNodeForHost(uri.host);
    if (endpoint == null) {
      return CustomLineDownloadRoute(url: url);
    }

    return CustomLineDownloadRoute(
      url: url,
      nodeName: node.name,
      originalHost: uri.host,
      proxy: endpoint,
    );
  }

  Future<HostMappingProxyEndpoint?> activateSelectedNodeForHost(String host) {
    return activateSelectedNodeForHosts([host]);
  }

  Future<HostMappingProxyEndpoint?> activateSelectedNodeForHosts(
    Iterable<String> hosts,
  ) async {
    if (!_canUseCustomLine()) {
      await HostMappingProxyService.instance.stop();
      return null;
    }

    final node = await getSelectedNode();
    if (node == null) {
      await HostMappingProxyService.instance.stop();
      return null;
    }

    final hostMap = <String, String>{};
    void addHost(String value) {
      final host = value.trim();
      if (host.isNotEmpty) hostMap[host] = node.ip;
    }

    addHost(node.host);
    for (final host in hosts) {
      addHost(host);
    }

    if (hostMap.isEmpty) {
      await HostMappingProxyService.instance.stop();
      return null;
    }
    return HostMappingProxyService.instance.configure(hostMap);
  }

  Future<HostMappingProxyEndpoint?> activateSelectedNodeForUrl(String url) {
    final uri = Uri.tryParse(url);
    return activateSelectedNodeForHost(uri?.host ?? '');
  }

  Future<HostMappingProxyEndpoint?> activateSelectedNodeForUrls(
    Iterable<String> urls,
  ) {
    final hosts = urls
        .map((url) => Uri.tryParse(url)?.host ?? '')
        .where((host) => host.trim().isNotEmpty);
    return activateSelectedNodeForHosts(hosts);
  }

  Future<void> configureMediaPlayerProxy(Player player, String url) async {
    final endpoint = await activateSelectedNodeForUrl(url);
    final platform = player.platform;
    if (platform is! NativePlayer) return;

    try {
      await platform.setProperty('http-proxy', endpoint?.proxyUri ?? '');
      AppLogger.d('媒体播放器自定义线路代理已配置: ${endpoint?.proxyUri ?? 'DIRECT'}');
    } catch (e) {
      AppLogger.d('媒体播放器自定义线路代理配置失败: $e');
    }
  }

  bool _canUseCustomLine() {
    final user = ServerService.instance.currentServer?.user;
    final groupName = user?.group?.name.trim().toLowerCase();
    return user != null &&
        groupName != null &&
        groupName.isNotEmpty &&
        groupName != 'user';
  }
}

class SelectedCustomLineNode {
  final String id;
  final String name;
  final String ip;
  final String host;
  final String protocol;
  final int? port;

  const SelectedCustomLineNode({
    required this.id,
    required this.name,
    required this.ip,
    required this.host,
    this.protocol = '',
    this.port,
  });

  bool get canRewriteDownloadUrl =>
      ip.trim().isNotEmpty && host.trim().isNotEmpty;

  String routeScheme(String fallback) {
    final value = protocol.trim().toLowerCase();
    return value == 'http' || value == 'https' ? value : fallback;
  }

  int? get routePort => port != null && port! > 0 ? port : null;

  factory SelectedCustomLineNode.fromJson(Map<String, dynamic> json) {
    return SelectedCustomLineNode(
      id: json['id']?.toString() ?? '',
      name: json['name']?.toString() ?? '',
      ip: json['ip']?.toString() ?? '',
      host: json['host']?.toString() ?? '',
      protocol: json['protocol']?.toString() ?? '',
      port: _asNullableInt(json['port']),
    );
  }

  Map<String, dynamic> toJson() {
    return {
      'id': id,
      'name': name,
      'ip': ip,
      'host': host,
      if (protocol.trim().isNotEmpty) 'protocol': protocol,
      if (routePort != null) 'port': routePort,
    };
  }

  static int? _asNullableInt(Object? value) {
    if (value is int) return value;
    if (value is num) return value.round();
    return int.tryParse(value?.toString() ?? '');
  }
}

class CustomLineDownloadRoute {
  final String url;
  final Map<String, String> headers;
  final String? nodeName;
  final String? originalHost;
  final HostMappingProxyEndpoint? proxy;

  const CustomLineDownloadRoute({
    required this.url,
    this.headers = const {},
    this.nodeName,
    this.originalHost,
    this.proxy,
  });

  bool get changed => proxy != null || headers.isNotEmpty;
}