import 'package:flutter/material.dart';

typedef OnInterceptor = Function(bool isInterceptor);

///  导航管理
class NavigatorManager {
  ///所有路由栈，包括弹窗与页面
  List<Route>? _history;

  static final NavigatorManager _instance = NavigatorManager._internal();

  factory NavigatorManager() => _instance;

  NavigatorManager? _bus;

  NavigatorManager._internal() {
    if (_bus == null) {
      _history = <Route>[];
    }
  }

  ///通过拦截器增加 push router
  void addRouter(Route route) {
    _history?.add(route);
  }

  ///通过拦截器移动 push router
  void removeRouter(Route route) {
    _history?.remove(route);
  }

  ///通过拦截器移动 push router
  void replaceRouter(Route newRoute, Route oldRoute) {
    _history?.remove(oldRoute);
    _history?.add(newRoute);
  }

  List<Route>? get history => _history;

  ///是否顶层路由为页面，或者还未显示，正在压入栈
  bool isTopRouter(String routerName) {
    if (_history!.isEmpty) {
      return false;
    }
    int i = _history!.length - 1;
    Route route = _history![i];
    while (route.settings == null && i >= 0) {
      i--;
      route = _history![i];
    }
    return route.settings.name != null && route.settings.name == routerName;
  }

  ///是否顶层路由为弹窗(包括showBottomSheet)，或者还未显示，正在压入栈
  bool isTopDialog() {
    if (_history!.isEmpty) {
      return false;
    }
    return _history![_history!.length - 1].settings.name == null;
  }
}