When I press the signup button i am getting an error occurred and it's is not creating a new user

Question

I am new to flutter, I am creating my app and in the auth screen when I try to signup a new user and press the signup button I am getting a message(an error occurred!) and I a don't know why and it is not creating the new user nor add him to the firebase authentication and when I press signup these are the tow messages that come on the debug console:I/ViewRootImpl@875f842MainActivity: ViewPostIme pointer 0 I/ViewRootImpl@875f842MainActivity: ViewPostIme pointer 1 so what can I do? this is the auth file:

import 'dart:math';

import 'package:app1/http_exception.dart';
import 'package:flutter/material.dart';

import 'package:shared_preferences/shared_preferences.dart';
import 'dart:convert';
import 'dart:async';
import 'package:http/http.dart' as http;

class Auth with ChangeNotifier {
 String _token;
 DateTime _expirydate;
 String _userid;
 Timer authtimer;
 bool get isauth {
   return token != null;
 }

 String get token {
   if (_expirydate != null &&
       _expirydate.isAfter(DateTime.now()) &&
       _token != null) {
     return token;
   }
   return null;
 }

 String get userid {
   return userid;
 }

 Future<void> authenticate(
     String email, String password, String urlseg) async {
   final url =
       'https://identitytoolkit.googleapis.com/v1/accounts:$urlseg?Key=AIzaSyC3csifqiu5s28nskttUnxz1UMz-sdfkjlksfmlksd';
   try {
     final res = await http.post(url,
         body: jsonEncode({
           'email': email,
           'password': password,
           'returnSecureToken': true
         }));
     final responsedata = json.decode(res.body);
     if (responsedata['error'] != null) {
       httpexception(responsedata['error']['message']);
     }
     _token = responsedata['idToken'];
     _userid = responsedata['localId'];
     _expirydate = DateTime.now()
         .add(Duration(seconds: int.parse(responsedata['expiresIn'])));
     _autologout();
     notifyListeners();
     final prefs = await SharedPreferences.getInstance();
     String userData = json.encode({
       'token': _token,
       'userId': _userid,
       'expiryDate': _expirydate.toIso8601String()
     });
     prefs.setString('userData', userData);
   } catch (e) {
     throw e;
   }
 }

 Future<void> signup(String email, String password) async {
   return authenticate(email, password, "signup");
 }

 Future<void> login(String email, String password) async {
   return authenticate(email, password, "signinWithPassword");
 }

 Future<bool> tryautologin() async {
   final prefs = await SharedPreferences.getInstance();
   if (!prefs.containsKey('userData')) return false;
   final Map<String, Object> extracteddata =
       json.decode(prefs.getString('userData')) as Map<String, Object>;
   final expirydate = DateTime.parse(extracteddata['expiryDate']);
   if (expirydate.isBefore(DateTime.now())) return false;
   _token = extracteddata['token'];
   _userid = extracteddata['userData'];
   _expirydate = extracteddata['expiryDate'];
   notifyListeners();
   _autologout();
   return true;
 }

 Future<void> logout() async {
   _token = null;
   _userid = null;
   _expirydate = null;
   if (authtimer != null) {
     authtimer.cancel();
     authtimer = null;
   }
   notifyListeners();
   final prefs = await SharedPreferences.getInstance();
   prefs.clear();
 }

 void _autologout() {
   if (authtimer != null) {
     authtimer.cancel();
     authtimer = null;
   }
   final timetoexpiry = _expirydate.difference(DateTime.now()).inSeconds;
   authtimer = Timer(Duration(seconds: timetoexpiry), logout);
 }
}

and that is the authscreen file:

import 'dart:math';

import 'package:app1/http_exception.dart';
import 'package:app1/providers/auth.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../http_exception.dart';

class Authscreen extends StatelessWidget {
 static const routname = '/auth';

 @override
 Widget build(BuildContext context) {
   final devicesize = MediaQuery.of(context).size;
   return Scaffold(
     body: Stack(
       children: [
         Container(
           decoration: BoxDecoration(
               gradient: LinearGradient(
             colors: [
               Color.fromRGBO(215, 117, 255, 1).withOpacity(0.5),
               Color.fromRGBO(215, 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: [
                 Flexible(
                   child: Container(
                     margin: EdgeInsets.only(bottom: 20),
                     padding: EdgeInsets.symmetric(
                       vertical: 8,
                       horizontal: 94,
                     ),
                     transform: Matrix4.rotationZ(-8 * pi / 180)
                       ..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(
                       'my shop',
                       style: TextStyle(
                         color:
                             Theme.of(context).accentTextTheme.headline6.color,
                         fontSize: 50,
                         fontFamily: 'Anton',
                       ),
                     ),
                   ),
                 ),
                 Flexible(
                     child: AuthCard(), flex: devicesize.width > 600 ? 2 : 1)
               ],
             ),
           ),
         )
       ],
     ),
   );
 }
}

class AuthCard extends StatefulWidget {
 @override
 AuthCardState createState() => AuthCardState();
}

enum Authmode { Login, Signup }

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();
 AnimationController controller;
 Animation<Offset> slideanimation;
 Animation<double> opacityanimation;
 @override
 void initState() {
   super.initState();
   controller =
       AnimationController(vsync: this, duration: Duration(milliseconds: 300));
   slideanimation = Tween<Offset>(begin: Offset(0, -0.15), 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));
 }

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

 Future<void> submit() async {
   if (!formkey.currentState.validate()) {
     return;
   }
   FocusScope.of(context).unfocus();
   formkey.currentState.save();
   setState(() {
     isloading = true;
   });
   try {
     if (authmode == Authmode.Login)
       await Provider.of<Auth>(context, listen: false)
           .login(authdata['email'], authdata['password']);
     else {
       await Provider.of<Auth>(context, listen: false)
           .signup(authdata['email'], authdata['password']);
     }
   } on httpexception catch (error) {
     var errormessage = 'Authentication failed';
     if (error.toString().contains('EMAIL_EXISTS')) {
       errormessage = 'This email is already in use';
     } else if (error.toString().contains('EMAIL_NOT_FOUND')) {
       errormessage = 'could not find a user with that email';
     } else if (error.toString().contains('INVALID_EMAIL')) {
       errormessage = 'this is not a valid email address';
     } else if (error.toString().contains('WEAK_PASSWORD')) {
       errormessage = 'This password is to short';
     } else if (error.toString().contains('INVALID_PASSWORD')) {
       errormessage = 'invalid password';
     }
     showerrordialog(errormessage);
   } catch (error) {
     const errormessage = 'please try again later';
     showerrordialog(errormessage);
   }
   setState(() {
     isloading = false;
   });
 }

 void switchauthmode() {
   if (authmode == Authmode.Login) {
     setState(() {
       authmode = Authmode.Signup;
     });
     controller.forward();
   } else {
     setState(() {
       authmode = Authmode.Login;
       controller.reverse();
     });
   }
 }

 void showerrordialog(String message) {
   showDialog(
       context: context,
       builder: (ctx) => AlertDialog(
             title: Text('an error occured!'),
             content: Text(message),
             actions: [
               TextButton(
                   onPressed: () => Navigator.of(context).pop(),
                   child: Text('okay!'))
             ],
           ));
 }

 @override
 Widget build(BuildContext context) {
   final devicesize = MediaQuery.of(context).size;
   return Card(
     shape: RoundedRectangleBorder(
       borderRadius: BorderRadius.circular(10),
     ),
     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),
         child: Form(
           key: formkey,
           child: SingleChildScrollView(
             child: Column(
               children: [
                 TextFormField(
                   decoration: InputDecoration(labelText: 'E-mail'),
                   keyboardType: TextInputType.emailAddress,
                   validator: (val) {
                     if (val.isEmpty || !val.contains('@')) {
                       return 'invalid email';
                     }
                     return null;
                   },
                   onSaved: (val) {
                     authdata['email'] = (val);
                   },
                 ),
                 TextFormField(
                   decoration: InputDecoration(labelText: 'Password'),
                   obscureText: true,
                   controller: passwordcontroller,
                   validator: (val) {
                     if (val.isEmpty || val.length < 7) {
                       return 'invalid password';
                     }
                     return null;
                   },
                   onSaved: (val) {
                     authdata['password'] = (val);
                   },
                 ),
                 AnimatedContainer(
                   constraints: BoxConstraints(
                     minHeight: authmode == Authmode.Signup ? 60 : 0,
                     maxHeight: authmode == Authmode.Signup ? 120 : 0,
                   ),
                   duration: Duration(milliseconds: 300),
                   curve: Curves.easeIn,
                   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
                             ? (val) {
                                 if (val != passwordcontroller.text) {
                                   return 'Password do not match';
                                 }
                                 return null;
                               }
                             : null,
                       ),
                     ),
                   ),
                 ),
                 SizedBox(
                   height: 20,
                 ),
                 if (isloading) CircularProgressIndicator(),
                 ElevatedButtonTheme(
                   data: ElevatedButtonThemeData(
                       style: ButtonStyle(
                     shape: MaterialStateProperty.all(
                       RoundedRectangleBorder(
                           borderRadius: BorderRadius.circular(30)),
                     ),
                     padding: MaterialStateProperty.all(
                         EdgeInsets.symmetric(vertical: 8, horizontal: 30)),
                     foregroundColor: MaterialStateProperty.all(
                         Theme.of(context).primaryTextTheme.headline6.color),
                   )),
                   child: ElevatedButton(
                     child:
                         Text(authmode == Authmode.Login ? 'LOGIN' : 'SIGNUP'),
                     onPressed: submit,
                   ),
                 ),
                 TextButtonTheme(
                     data: TextButtonThemeData(
                       style: ButtonStyle(
                         padding: MaterialStateProperty.all(
                             EdgeInsets.symmetric(
                                 vertical: 4, horizontal: 30)),
                         foregroundColor: MaterialStateProperty.all(
                             Theme.of(context).primaryColor),
                       ),
                     ),
                     child: TextButton(
                       onPressed: switchauthmode,
                       child: Text(
                           '${authmode == Authmode.Login ? 'SIGNUP' : 'LOGIN'} INSTEAD'),
                     ))
               ],
             ),
           ),
         )),
   );
 }
}