oc-front/lib/core/services/router.dart

import 'package:oc_front/core/sections/header/header.dart';
import 'package:oc_front/main.dart';
import 'package:oc_front/pages/abstract_page.dart';
import 'package:oc_front/pages/catalog.dart';
import 'package:oc_front/pages/catalog_item.dart';
import 'package:oc_front/pages/datacenter.dart';
import 'package:oc_front/pages/map.dart';
import 'package:oc_front/pages/scheduler.dart';
import 'package:oc_front/pages/shared.dart';
import 'package:oc_front/pages/workflow.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';

GlobalKey<RouterWidgetState> routerKey = GlobalKey<RouterWidgetState>();

class RouterWidget extends StatefulWidget {
  const RouterWidget({Key? key}) : super(key: key);
  @override RouterWidgetState createState() => RouterWidgetState();
}

class RouterWidgetState extends State<RouterWidget> {
  @override Widget build(BuildContext context) {
    return Padding( padding: const EdgeInsets.only(right: 20), child: Row(children: [
      IconButton(onPressed: () async => AppRouter.realHistory.length > 1 ? AppRouter.back() : null, icon: Icon(Icons.arrow_back, color: AppRouter.realHistory.length > 1 ? Colors.white : Theme.of(context).splashColor)),
      IconButton(onPressed: () async => AppRouter.canForward() ? AppRouter.forward() : null, icon: Icon(Icons.arrow_forward, color: AppRouter.canForward() ? Colors.white : Theme.of(context).splashColor)),
    ],));
  }
}

class RouterItem {
  final IconData? icon;
  final String? label;
  final String route;
  final String? description;
  final String? help;
  final AbstractFactory factory;
  List<String> args = [];
  RouterItem({this.icon, this.label, this.description, this.help,
              required this.route, required this.factory, this.args = const []});
  String get path => "/${route == AppRouter.home ? "" : route}";

  void go(BuildContext context, Map<String, String> params) { 
    AppRouter.currentRoute = this;
    var newPath = "$path";
    for (var arg in args) { newPath = newPath.replaceAll(":$arg", params[arg] ?? ""); }
    Future.delayed( const Duration(seconds: 1), () {
      HeaderConstants.setTitle(null);
      HeaderConstants.setDescription(null);
    });
    context.go(newPath); 
  }
}

class AppRouter { 
  static String home = "catalog";
  static final RouterItem workflowItem = RouterItem(icon: Icons.rebase_edit, label: "workflow manager", route: "workflow", 
      factory: WorkflowFactory());
  static final RouterItem workflowIDItem = RouterItem(description: "", help: "", route: "workflow/:id", factory: WorkflowFactory(), args: ["id"]);
  static final RouterItem catalogItem = RouterItem(description: "", help: "", route: "catalog/:id", factory: CatalogItemFactory(), args: ["id"]);
  static final RouterItem catalog= RouterItem(icon: Icons.book_outlined, label: "catalog searcher", route: "catalog", factory: CatalogFactory());
  static final RouterItem scheduler = RouterItem(icon: Icons.schedule, label: "scheduled tasks", route: "scheduler", factory: SchedulerFactory());
  static final RouterItem compute = RouterItem(icon: Icons.dns_outlined, label: "my compute", route: "compute", factory: DatacenterFactory());
  static final RouterItem shared = RouterItem(icon: Icons.share_rounded, label: "collaborative area", route: "shared", factory: SharedFactory());

  static List<RouterItem> zones = [
    catalog, 
    workflowItem, 
    scheduler,
    compute,
    RouterItem(icon: Icons.public_outlined, label: "localisations", route: "map", factory: MapFactory()),
    shared,
    workflowIDItem,
    catalogItem,
  ];
  static List<String> history = [];
  static List<String> realHistory = [];
  static final AppRouter _instance = AppRouter._internal();
  factory AppRouter() { return _instance; }
  AppRouter._internal() { 
    SharedPreferences.getInstance().then((prefs) {
      if (prefs.containsKey("history")) {
        realHistory = prefs.getString("history")!.split(",");
        history = prefs.getString("history")!.split(",");
        routerKey.currentState?.setState(() { });
      }
    });
  }    

  static Future<String?> getRouteCookie() async {
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    return prefs.getString("url") != "" ? prefs.getString("url") : null;
  }

  static removeRouteCookie() async {
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.remove("url");
  }

  static setRouteCookie( String path , BuildContext context ) async {
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.setString("url", path);
    if (realHistory.isNotEmpty && realHistory.last != path || realHistory.isEmpty) {
      try {
        var index = history.indexOf(realHistory.last);
        history = history.sublist(0, index + 1);
      } catch (e) { /* */ }
      realHistory.add(path);
      history.add(path);
      if (history.length > 10) { 
        realHistory.removeAt(0); 
        history.removeAt(0);
      }
      prefs.setString("history", realHistory.join(","));
      routerKey.currentState?.setState(() { });
    }
  }

  static back() async {
    if (realHistory.length <= 1) { return; }
    realHistory.removeLast();
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.setString("url", realHistory.last);
    prefs.setString("history", realHistory.join(","));
    var splitted = realHistory.last.split(":");
    routerKey.currentState?.setState(() { });
    scaffoldKey.currentState?.setState(() {});
  }
  static bool canForward() {
    try {
      var index = history.indexOf(realHistory.last);
      return (index + 1) < history.length;
    } catch (e) { return false; }
    
  }
  static forward() async {
    if (canForward()) { 
      var index = history.indexOf(realHistory.last);
      realHistory.add(history[index + 1]); 
      final SharedPreferences prefs = await SharedPreferences.getInstance();
      prefs.setString("url", realHistory.last);
      var splitted = realHistory.last.split(":");
      prefs.setString("history", realHistory.join(","));
      routerKey.currentState?.setState(() { });
      scaffoldKey.currentState?.setState(() {});
    }
  }

  static RouterItem currentRoute = zones.first;    
  static List<RouteBase> get routes => zones.map( (k) => GoRoute(
      name: k.route, 
      path: k.path,
      builder: (BuildContext context, GoRouterState state) { 
        return MainPage(page: k.factory.factory(state, k.args)); 
      },
    )).toList();
}   
// ROUTER SHOULD INVOKE MAIN TO ACCESS VIEW, VIEW ARE MENU SECTION