// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// ignore_for_file: public_member_api_docs

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:local_auth_android/local_auth_android.dart';
import 'package:local_auth_platform_interface/local_auth_platform_interface.dart';

void main() {
  runApp(const MyApp());
}

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

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  _SupportState _supportState = _SupportState.unknown;
  bool? _deviceSupportsBiometrics;
  List<BiometricType>? _enrolledBiometrics;
  String _authorized = 'Not Authorized';
  bool _isAuthenticating = false;

  @override
  void initState() {
    super.initState();
    LocalAuthPlatform.instance.isDeviceSupported().then(
          (bool isSupported) => setState(() => _supportState = isSupported
              ? _SupportState.supported
              : _SupportState.unsupported),
        );
  }

  Future<void> _checkBiometrics() async {
    late bool deviceSupportsBiometrics;
    try {
      deviceSupportsBiometrics =
          await LocalAuthPlatform.instance.deviceSupportsBiometrics();
    } on PlatformException catch (e) {
      deviceSupportsBiometrics = false;
      print(e);
    }
    if (!mounted) {
      return;
    }

    setState(() {
      _deviceSupportsBiometrics = deviceSupportsBiometrics;
    });
  }

  Future<void> _getEnrolledBiometrics() async {
    late List<BiometricType> availableBiometrics;
    try {
      availableBiometrics =
          await LocalAuthPlatform.instance.getEnrolledBiometrics();
    } on PlatformException catch (e) {
      availableBiometrics = <BiometricType>[];
      print(e);
    }
    if (!mounted) {
      return;
    }

    setState(() {
      _enrolledBiometrics = availableBiometrics;
    });
  }

  Future<void> _authenticate() async {
    bool authenticated = false;
    try {
      setState(() {
        _isAuthenticating = true;
        _authorized = 'Authenticating';
      });
      authenticated = await LocalAuthPlatform.instance.authenticate(
        localizedReason: 'Let OS determine authentication method',
        authMessages: <AuthMessages>[const AndroidAuthMessages()],
        options: const AuthenticationOptions(
          useErrorDialogs: true,
          stickyAuth: true,
        ),
      );
      setState(() {
        _isAuthenticating = false;
      });
    } on PlatformException catch (e) {
      print(e);
      setState(() {
        _isAuthenticating = false;
        _authorized = 'Error - ${e.message}';
      });
      return;
    }
    if (!mounted) {
      return;
    }

    setState(
        () => _authorized = authenticated ? 'Authorized' : 'Not Authorized');
  }

  Future<void> _authenticateWithBiometrics() async {
    bool authenticated = false;
    try {
      setState(() {
        _isAuthenticating = true;
        _authorized = 'Authenticating';
      });
      authenticated = await LocalAuthPlatform.instance.authenticate(
        localizedReason:
            'Scan your fingerprint (or face or whatever) to authenticate',
        authMessages: <AuthMessages>[const AndroidAuthMessages()],
        options: const AuthenticationOptions(
          useErrorDialogs: true,
          stickyAuth: true,
          biometricOnly: true,
        ),
      );
      setState(() {
        _isAuthenticating = false;
        _authorized = 'Authenticating';
      });
    } on PlatformException catch (e) {
      print(e);
      setState(() {
        _isAuthenticating = false;
        _authorized = 'Error - ${e.message}';
      });
      return;
    }
    if (!mounted) {
      return;
    }

    final String message = authenticated ? 'Authorized' : 'Not Authorized';
    setState(() {
      _authorized = message;
    });
  }

  Future<void> _cancelAuthentication() async {
    await LocalAuthPlatform.instance.stopAuthentication();
    setState(() => _isAuthenticating = false);
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Plugin example app'),
        ),
        body: ListView(
          padding: const EdgeInsets.only(top: 30),
          children: <Widget>[
            Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                if (_supportState == _SupportState.unknown)
                  const CircularProgressIndicator()
                else if (_supportState == _SupportState.supported)
                  const Text('This device is supported')
                else
                  const Text('This device is not supported'),
                const Divider(height: 100),
                Text(
                    'Device supports biometrics: $_deviceSupportsBiometrics\n'),
                ElevatedButton(
                  onPressed: _checkBiometrics,
                  child: const Text('Check biometrics'),
                ),
                const Divider(height: 100),
                Text('Enrolled biometrics: $_enrolledBiometrics\n'),
                ElevatedButton(
                  onPressed: _getEnrolledBiometrics,
                  child: const Text('Get enrolled biometrics'),
                ),
                const Divider(height: 100),
                Text('Current State: $_authorized\n'),
                if (_isAuthenticating)
                  ElevatedButton(
                    onPressed: _cancelAuthentication,
                    child: Row(
                      mainAxisSize: MainAxisSize.min,
                      children: const <Widget>[
                        Text('Cancel Authentication'),
                        Icon(Icons.cancel),
                      ],
                    ),
                  )
                else
                  Column(
                    children: <Widget>[
                      ElevatedButton(
                        onPressed: _authenticate,
                        child: Row(
                          mainAxisSize: MainAxisSize.min,
                          children: const <Widget>[
                            Text('Authenticate'),
                            Icon(Icons.perm_device_information),
                          ],
                        ),
                      ),
                      ElevatedButton(
                        onPressed: _authenticateWithBiometrics,
                        child: Row(
                          mainAxisSize: MainAxisSize.min,
                          children: <Widget>[
                            Text(_isAuthenticating
                                ? 'Cancel'
                                : 'Authenticate: biometrics only'),
                            const Icon(Icons.fingerprint),
                          ],
                        ),
                      ),
                    ],
                  ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

enum _SupportState {
  unknown,
  supported,
  unsupported,
}