mirrored_repositories/shop/lib
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../provider/auth.dart';
import '../models/http_exception.dart';

enum AuthMode { Signup, Login }

class AuthScreen extends StatelessWidget {
  static const routeName = '/auth';

  @override
  Widget build(BuildContext context) {
    final deviceSize = MediaQuery.of(context).size;
    //to avoid .. in one line use this below code
    // final transformConfig = Matrix4.rotationZ(-8 * pi / 180);
    // transformConfig.translate(-10.0);
    return Scaffold(
      // resizeToAvoidBottomInset: false,
      body: Stack(
        children: <Widget>[
          Container(
            decoration: BoxDecoration(
              gradient: LinearGradient(
                colors: [
                  Color.fromRGBO(215, 117, 255, 1).withOpacity(0.5),
                  Color.fromRGBO(255, 188, 117, 1).withOpacity(0.9),
                ],
                begin: Alignment.topLeft,
                end: Alignment.bottomRight,
                stops: [0, 1],
              ),
            ),
          ),
          SingleChildScrollView(
            child: Container(
              height: deviceSize.height,
              width: deviceSize.width,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.center,
                children: <Widget>[
                  Flexible(
                    child: Container(
                      margin: EdgeInsets.only(bottom: 20.0),
                      padding:
                          EdgeInsets.symmetric(vertical: 8.0, horizontal: 94.0),
                      transform: Matrix4.rotationZ(-8 * pi / 180)
                        ..translate(-10.0),
                      // ..translate(-10.0),
                      decoration: BoxDecoration(
                        borderRadius: BorderRadius.circular(20),
                        color: Colors.deepOrange.shade900,
                        boxShadow: [
                          BoxShadow(
                            blurRadius: 8,
                            color: Colors.black26,
                            offset: Offset(0, 2),
                          )
                        ],
                      ),
                      child: Text(
                        'MyShop',
                        style: TextStyle(
                          color: Theme.of(context).accentTextTheme.title.color,
                          fontSize: 50,
                          fontFamily: 'Anton',
                          fontWeight: FontWeight.normal,
                        ),
                      ),
                    ),
                  ),
                  Flexible(
                    flex: deviceSize.width > 600 ? 2 : 1,
                    child: AuthCard(),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}

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

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

class _AuthCardState extends State<AuthCard> with SingleTickerProviderStateMixin{
  final GlobalKey<FormState> _formKey = GlobalKey();
  AuthMode _authMode = AuthMode.Login;
  Map<String, String> _authData = {
    'email': '',
    'password': '',
  };
  var _isLoading = false;
  final _passwordController = TextEditingController();

  var containerHeight=260;
  AnimationController _controller;
  Animation<Offset> _slideAnimation;
  Animation<double> _opacityAnimation;


  @override
  void initState() {
    
    _controller=AnimationController(
      vsync: this,
      duration: Duration(
        milliseconds: 300,
      )
    );

    _slideAnimation=Tween<Offset>(
      begin: Offset(0,-1.5),
      end:Offset(0,0) ,
    ).animate(
      CurvedAnimation(
        parent: _controller,
        curve: Curves.fastOutSlowIn,
      ),
    );

    _opacityAnimation=Tween<double>(
      begin: 0.0,
      end: 1.0 ,
    ).animate(
      CurvedAnimation(
        parent: _controller,
        curve: Curves.easeIn,
      ),
    );

    //by your self change curve property 

    /*
    _controller.addListener(() { 
      setState(() {
        
      });
    });
    */

    super.initState();
  } 

  @override
  void dispose() {
    
    _controller.dispose();
    super.dispose();
  }
  

  void _showErrorDialog(String message){
    showDialog(
      context: context,
      builder: (ctx)=>AlertDialog(
        title: Text('An error occured!'),
        content: Text(message),
        actions: <Widget>[
          FlatButton(
            onPressed: (){
              Navigator.of(ctx).pop();
            }, 
            child: Text('Okay')
          )
        ],
      ),
    );
  }

  Future<void> _submit() async {
    if (!_formKey.currentState.validate()) {
      // Invalid!
      return;
    }
    _formKey.currentState.save();
    setState(() {
      _isLoading = true;
    });


    try{

      if (_authMode == AuthMode.Login) {
        // Log user in
        await Provider.of<Auth>(context, listen: false).login(
          _authData['email'],
          _authData['password'],
        );
      } else {
        // Sign user up
        await Provider.of<Auth>(context, listen: false).signup(
          _authData['email'],
          _authData['password'],
        );
      }

    }
    on HttpException catch(error){
      print(error);
      var errorMsg='Authentication fail.';
      if(error.toString().contains('EMAIL_EXISTS')){
        errorMsg='This Email address is already in use';
      }
      else if(error.toString().contains('INVALID_EMAIL')){
        errorMsg='This Email is not valid';
      }
      else if(error.toString().contains('WEAK_PASSWORD')){
        errorMsg='This password is too short';
      }
      else if(error.toString().contains('EMAIL_NOT_FOUND')){
        errorMsg='Could not found your email please sign up!';
      }
      else if(error.toString().contains('INVALID_PASSWORD')){
        errorMsg='Wrong password';
      }
      _showErrorDialog(errorMsg);
    }
    catch(error){
      const  errorMsg='Could not authenticate you.\nPlease check your network connectivity and try again later.';
      _showErrorDialog(errorMsg);
    }
    

    setState(() {
      _isLoading = false;
    });
  }

  void _switchAuthMode() {
    if (_authMode == AuthMode.Login) {
      setState(() {
        _authMode = AuthMode.Signup;
      });
      _controller.forward();
    } else {
      setState(() {
        _authMode = AuthMode.Login;
      });
      _controller.reverse();
    }
  }

  @override
  Widget build(BuildContext context) {
    final deviceSize = MediaQuery.of(context).size;
    return Card(
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(10.0),
      ),
      elevation: 8.0,
      child: AnimatedContainer(
        duration: Duration(
          milliseconds: 300,
        ),
        curve: Curves.easeIn,
        height: _authMode==AuthMode.Signup? 320:260,
        constraints:
            BoxConstraints(minHeight:_authMode==AuthMode.Signup? 320:260, ),
        width: deviceSize.width * 0.75,
        padding: EdgeInsets.all(16.0),
        child:Form(
          key: _formKey,
          child: SingleChildScrollView(
            child: Column(
              children: <Widget>[
                TextFormField(
                  decoration: InputDecoration(labelText: 'E-Mail'),
                  keyboardType: TextInputType.emailAddress,
                  validator: (value) {
                    if (value.isEmpty || !value.contains('@')) {
                      return 'Invalid email!';
                    }
                  },
                  onSaved: (value) {
                    _authData['email'] = value;
                  },
                ),
                TextFormField(
                  decoration: InputDecoration(labelText: 'Password'),
                  obscureText: true,
                  controller: _passwordController,
                  validator: (value) {
                    if (value.isEmpty || value.length < 5) {
                      return 'Password is too short!';
                    }
                  },
                  onSaved: (value) {
                    _authData['password'] = value;
                  },
                ),
                AnimatedContainer(
                  constraints: BoxConstraints(
                    minHeight: _authMode==AuthMode.Signup?60:0,
                    maxHeight: _authMode==AuthMode.Signup?120:0,
                  ),
                  curve: Curves.easeIn,
                  duration: Duration(milliseconds: 300),                
                  child: FadeTransition(
                    opacity: _opacityAnimation,
                    child: SlideTransition(
                      position: _slideAnimation,
                      child: TextFormField(
                        enabled: _authMode == AuthMode.Signup,
                        decoration: InputDecoration(labelText: 'Confirm Password'),
                        obscureText: true,
                        validator: _authMode == AuthMode.Signup
                            ? (value) {
                                if (value != _passwordController.text) {
                                  return 'Passwords do not match!';
                                }
                              }
                            : null,
                      ),
                    ),
                  ),
                ),
                SizedBox(
                  height: 20,
                ),
                if (_isLoading)
                  CircularProgressIndicator()
                else
                  RaisedButton(
                    child:
                        Text(_authMode == AuthMode.Login ? 'LOGIN' : 'SIGN UP'),
                    onPressed: _submit,
                    shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(30),
                    ),
                    padding:
                        EdgeInsets.symmetric(horizontal: 30.0, vertical: 8.0),
                    color: Theme.of(context).primaryColor,
                    textColor: Theme.of(context).primaryTextTheme.button.color,
                  ),
                FlatButton(
                  child: Text(
                      '${_authMode == AuthMode.Login ? 'SIGNUP' : 'LOGIN'} INSTEAD'),
                  onPressed: _switchAuthMode,
                  padding: EdgeInsets.symmetric(horizontal: 30.0, vertical: 4),
                  materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
                  textColor: Theme.of(context).primaryColor,
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}
