import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:photos/core/configuration.dart';
import 'package:photos/core/event_bus.dart';
import 'package:photos/events/user_authenticated_event.dart';
import 'package:photos/ui/common_elements.dart';
import 'package:photos/ui/email_entry_page.dart';
import 'package:photos/ui/passphrase_entry_page.dart';
import 'package:photos/ui/passphrase_reentry_page.dart';

class SignInHeader extends StatefulWidget {
  const SignInHeader({Key key}) : super(key: key);

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

class _SignInHeaderState extends State<SignInHeader> {
  StreamSubscription _userAuthEventSubscription;

  @override
  void initState() {
    _userAuthEventSubscription =
        Bus.instance.on<UserAuthenticatedEvent>().listen((event) {
      setState(() {});
    });
    super.initState();
  }

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

  @override
  Widget build(BuildContext context) {
    if (Configuration.instance.hasConfiguredAccount()) {
      return Container();
    }
    return Container(
      padding: EdgeInsets.all(8),
      child: Column(
        children: [
          Text(
            "Preserve Your Memories",
            style: TextStyle(
              fontSize: 16,
            ),
          ),
          Container(
            width: double.infinity,
            height: 64,
            padding: EdgeInsets.all(8),
            child: button(
              "Sign In",
              fontSize: 18,
              onPressed: () {
                var page;
                if (Configuration.instance.getToken() == null) {
                  page = EmailEntryPage();
                } else {
                  // No key
                  if (Configuration.instance.getKeyAttributes() != null) {
                    // Yet to set or decrypt the key
                    page = PassphraseReentryPage();
                  } else {
                    // Never had a key
                    page = PassphraseEntryPage();
                  }
                }
                Navigator.of(context).push(
                  MaterialPageRoute(
                    builder: (BuildContext context) {
                      return page;
                    },
                  ),
                );
              },
            ),
          ),
          Padding(padding: EdgeInsets.all(4)),
          Divider(
            height: 2,
          ),
        ],
      ),
    );
  }
}