main.dart

import 'package:flutter/material.dart';
import 'package:bencana/constants.dart';
import 'package:bencana/home.dart';
import 'package:bencana/disaster.dart';
import 'package:bencana/missing.dart';
import 'package:bencana/authentication.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'dart:async';
import 'package:bencana/post_add.dart';
import 'package:bencana/disaster_add.dart';
import 'package:bencana/missing_add.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.teal,
      ),
//      home: MyHomePage(title: 'Flutter Demo Home Page'),
      home: DashboardScreen(title: 'B-Alert'),
    );
  }
}

class DashboardScreen extends StatefulWidget {
  // 1. Deklarasikan parameter untuk DashboardScreen
  DashboardScreen({Key key, this.title}) : super(key: key);
  final String title;

  @override
  _DashboardScreenState createState() => _DashboardScreenState();
}

enum AuthStatus { signIn, notSignIn }

class _DashboardScreenState extends State<DashboardScreen> {
  // 2. deklarasikan page controller dan initial page
  PageController _pageController;
  int _page = 0;

  AuthStatus _authStatus = AuthStatus.signIn;

  // 3. Inisialisasi page controller pada init state
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _pageController = PageController();

    getCurrentUser().then((userId) {
      setState(() {
        _authStatus = userId == null ? AuthStatus.notSignIn : AuthStatus.signIn;
      });
    });
  }

  // 4. Buang page controller jika tidak dibutuhkan lagi
  @override
  void dispose() {
    // TODO: implement dispose
    super.dispose();
    _pageController.dispose();
  }

  // 5. Animasi perpindahan antar page
  void navigationTapped(int page) {
    _pageController.animateToPage(
      page,
      duration: const Duration(milliseconds: 300),
      curve: Curves.ease,
    );
  }

  // 6. Tangani perpindahan page
  void onPageChanged(int page) {
    setState(() {
      this._page = page;
    });
  }

  // 7. Deklarasikan list untuk menu item di file Constants.dart

  // 8. Siapkan aksi untuk pilihan menu item
  void selectedAction(String choice) {
    print('You choose: $choice');
    if (choice == Constants.signout) {
      signOut();
    }
  }

  Future<String> getCurrentUser() async {
    try {
      FirebaseUser user = await FirebaseAuth.instance.currentUser();
      return user.uid;
    } catch (e) {
      print('Error: $e');
      return null;
    }
  }

  void signOut() async {
    try {
      FirebaseAuth.instance.signOut();
      setState(() {
        _authStatus = AuthStatus.notSignIn;
      });
    } catch (e) {
      print('Error: $e');
    }
  }

  @override
  Widget build(BuildContext context) {
    switch (_authStatus) {
      case AuthStatus.notSignIn:
        return AuthenticationPage();
      case AuthStatus.signIn:
        return Scaffold(
          appBar: AppBar(
            title: Text(
              widget.title,
            ),
            actions: <Widget>[
              PopupMenuButton<String>(
                onSelected: selectedAction,
                itemBuilder: (BuildContext context) {
                  return Constants.choices.map((String choice) {
                    return PopupMenuItem<String>(
                      value: choice,
                      child: Text(choice),
                    );
                  }).toList();
                },
              ),
            ],
          ),
          body: PageView(
            children: <Widget>[
              HomePage(),
              DisasterPage(),
              MissingPage(),
            ],
            onPageChanged: onPageChanged,
            controller: _pageController,
          ),
          floatingActionButton: FloatingActionButton(
            onPressed: () {
              // Set FAB sesuai dengan page
              switch (_page) {
                case 0:
                  Navigator.push(
                    context,
                    MaterialPageRoute(builder: (context) => PostAdd()),
                  );
                  break;
                case 1:
                  Navigator.push(
                    context,
                    MaterialPageRoute(builder: (context) => DisasterAdd()),
                  );
                  break;
                case 2:
                  Navigator.push(
                    context,
                    MaterialPageRoute(builder: (context) => MissingAdd()),
                  );
                  break;
              }
            },
            child: Icon(Icons.add),
          ),
          bottomNavigationBar: Theme(
            data: Theme.of(context).copyWith(
              canvasColor: Colors.teal[100],
            ),
            child: BottomNavigationBar(
              items: [
                BottomNavigationBarItem(
                  icon: Icon(Icons.announcement),
                  title: Text('News'),
                ),
                BottomNavigationBarItem(
                  icon: Icon(Icons.warning),
                  title: Text('Disaster'),
                ),
                BottomNavigationBarItem(
                  icon: Icon(Icons.people),
                  title: Text('Missing'),
                ),
              ],
              onTap: navigationTapped,
              currentIndex: _page,
              fixedColor: Colors.teal,
            ),
          ),
        );
    }
  }
}