import 'dart:async';

import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_database/firebase_database.dart';
import 'package:firebase_database/ui/firebase_animated_list.dart';

class CarnivalCompassHome extends StatefulWidget {
  @override
  CarnivalCompassHomeState createState() => new CarnivalCompassHomeState();
}

class CarnivalCompassHomeState extends State<CarnivalCompassHome> {
  final DatabaseReference _bandRef =
  FirebaseDatabase.instance.reference().child('bands');
  final DatabaseReference _messagesRef =
  FirebaseDatabase.instance.reference().child('messages');
  StreamSubscription<Event> _bandSubscription;
  StreamSubscription<Event> _messagesSubscription;
  bool _anchorToBottom = false;

  String _kTestKey = 'Hello';
  String _kTestValue = 'world!';

  @override
  void initState() {
    super.initState();
    FirebaseAuth.instance.currentUser().then((FirebaseUser firebaseUser) {
      if (firebaseUser == null) {
        FirebaseAuth.instance.signInAnonymously();
        print('Signing in anonymously');
      } else {
        print('Already signed in anonymously');
      }
    });
    FirebaseDatabase.instance.setPersistenceEnabled(true);
    FirebaseDatabase.instance.setPersistenceCacheSizeBytes(10000000);
    _bandRef.keepSynced(true);
    _bandSubscription = _bandRef.onValue.listen((Event event) {
      //setState(() {
        //_counter = event.snapshot.value ?? 0;
      //});
    });
    _messagesSubscription =
      _messagesRef.limitToLast(10).onChildAdded.listen((Event event) {
        print('Child added: ${event.snapshot.value}');
      });
  }

  @override
  void dispose() {
    super.dispose();
    _messagesSubscription.cancel();
    _bandSubscription.cancel();
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Carnival Compass'),
      ),
      body: new Column(
        children: <Widget>[
          new Text('i am working'),
          new Flexible(
            child: new FirebaseAnimatedList(
              key: new ValueKey<bool>(_anchorToBottom),
              query: _messagesRef,
              reverse: _anchorToBottom,
              sort: _anchorToBottom
                ? (DataSnapshot a, DataSnapshot b) => b.key.compareTo(a.key)
                : null,
              itemBuilder: (BuildContext context, DataSnapshot snapshot,
                Animation<double> animation, int index) {
                  return new SizeTransition(
                    sizeFactor: animation,
                    child: new Text("Here: $index: ${snapshot.value.toString()}"),
                  );
                },
            ),
          ),
        ],
      ),
    );
  }
}