import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:jpush_flutter/jpush_flutter.dart';
import 'package:jpush_flutter/jpush_interface.dart';
import 'package:permission_handler/permission_handler.dart';

import '../config.dart';
import '../nav.dart';
import '../screens/home_screen.dart';
import 'im_service.dart';

/// 极光推送封装：初始化、通知权限、Registration ID、把 OpenIM userID 设为 alias。
///
/// OpenIM 服务端 JPUSH 离线推送按 alias=userID 下发，因此登录后必须 setAlias。
/// 本阶段只接安卓；iOS 不调用 setup。
class PushService {
  PushService._();

  static final PushService instance = PushService._();

  final JPushFlutterInterface _jpush = JPush.newJPush();
  bool _ready = false;
  String? _boundAlias;

  Future<void> init() async {
    if (_ready) return;
    if (kIsWeb || !Platform.isAndroid) return;
    try {
      _jpush.addEventHandler(
        onReceiveNotification: (message) async {},
        onOpenNotification: (message) async {
          _onNotificationClick();
        },
        onReceiveMessage: (message) async {},
        onReceiveNotificationAuthorization: (message) async {},
        onConnected: (message) async {},
        onCommandResult: (message) async {},
      );
      _jpush.setAuth(enable: true);
      _jpush.setup(
        appKey: jpushAppKey,
        channel: 'developer-default',
        production: true,
        debug: false,
      );
      _jpush.applyPushAuthority(
        const NotificationSettingsIOS(sound: true, alert: true, badge: true),
      );
      await _requestAndroidNotificationPermission();
      _ready = true;
      await _jpush.getRegistrationID();
    } catch (_) {
      // 推送失败不能挡住登录和聊天
    }
  }

  Future<void> bindUser(String userID) async {
    if (userID.isEmpty) return;
    await init();
    if (!_ready) return;
    try {
      await _jpush.setAlias(userID);
      _boundAlias = userID;
    } catch (_) {
      // alias 失败时下次登录再试
    }
  }

  Future<void> unbindUser() async {
    if (!_ready) return;
    try {
      await _jpush.deleteAlias();
    } catch (_) {
      // 本地照常清理
    }
    _boundAlias = null;
  }

  String? get boundAlias => _boundAlias;

  Future<void> _requestAndroidNotificationPermission() async {
    try {
      final status = await Permission.notification.status;
      if (!status.isGranted) {
        await Permission.notification.request();
      }
    } catch (_) {
      // 权限申请失败不阻断
    }
  }

  void _onNotificationClick() {
    final nav = navigatorKey.currentState;
    if (nav == null) return;
    if (!IMService.instance.loggedIn) return;
    nav.pushAndRemoveUntil(
      MaterialPageRoute(builder: (_) => const HomeScreen()),
      (route) => false,
    );
  }
}