Flutter Error

import 'dart:async';
import 'dart:convert';

import 'package:app/auth/login_or_register.dart';
import 'package:app/pages/shared/login/login_page.dart';
import 'package:app/pages/shared/widgets/button_global.dart';
import 'package:app/pages/shared/widgets/custom_snackbar.dart';
import 'package:app/pages/shared/widgets/text_form_global.dart';
import 'package:app/pages/shared/widgets/text_global.dart';
import 'package:app/utils/dio_routes.dart';
import 'package:app/utils/global.colors.dart';
import 'package:dio/dio.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';

class SignUpPage extends StatefulWidget {
  final void Function()? onTap;

  const SignUpPage({super.key, required this.onTap});

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

class _SignUpPageState extends State<SignUpPage> {
  bool _isLoading = false;
  bool _redirecting = false;
  late final TextEditingController _emailController = TextEditingController();
  late final TextEditingController _passwordController =
      TextEditingController();
  late final TextEditingController _firstNameController =
      TextEditingController();
  late final TextEditingController _lastNameController =
      TextEditingController();


  /*  void register() async {
    // show loading screen
    showDialog(
      context: context,
      builder: (context) => const Center(
        child: CircularProgressIndicator(),
      ),
    );

    // try create the user
    try {
      UserCredential? userCredential = await FirebaseAuth.instance
          .createUserWithEmailAndPassword(
              email: _emailController.text, password: _passwordController.text);

      if (mounted) {
        // create user document and send it to api
        await createUserData(context, userCredential.user!.uid);
        Navigator.pop(context);
      } else {
        // you can't use the context
      }

      // pop loading circle
    } on FirebaseException catch (e) {
      // pop loading circle
      //Navigator.pop(context);

      // display error message to user
      displayNotification(context, e.code);
    }
  }

  Future createUserData(BuildContext context, String uid) async {
    try {
      var data = {
        "userId": uid,
        "clientName": _firstNameController.text.toString(),
        "email": _emailController.text.toString(),
      };

      Response response =
          await Dio().post(createAccountEndpoint, data: jsonEncode(data));

      if (response.statusCode == 200) {
        // display error message
        displayNotification(context, "Your account was created successfully!");
        Navigator.push(
          context,
          MaterialPageRoute(builder: (context) => const LoginOrRegister()),
        );
      } else {
        displayNotification(context, "Error!");
      }
    } on DioException catch (e) {
      print("Create Account ERROR ->  ${e.message}");
    }
  } */

  void register() async {
    // show loading screen
    showDialog(
      context: context,
      builder: (context) => const Center(
        child: CircularProgressIndicator(),
      ),
    );

    // try create the user
    final result = await createUser();

    displayNotification(context, result.values.first);

    Navigator.pop(context);

    if (result.keys.first) {
      Navigator.push(
        context,
        MaterialPageRoute(builder: (context) => const LoginOrRegister()),
      );
    }
  }

  Future<Map<bool, String>> createUser() async {
    try {
      UserCredential? userCredential = await FirebaseAuth.instance
          .createUserWithEmailAndPassword(
              email: _emailController.text, password: _passwordController.text);

      final uid = userCredential.user!.uid;

      var data = {
        "userId": uid,
        "clientName": _firstNameController.text.toString(),
        "email": _emailController.text.toString(),
      };

      Response response =
          await Dio().post(createAccountEndpoint, data: jsonEncode(data));

      if (response.statusCode == 200) {
        return {true: "Your account was created successfully!"};
      }
      return {false: "Error!"};
    } on FirebaseException catch (e) {
      return {false: "${e.code}"};
    } on DioException catch (e) {
      print("Create Account ERROR ->  ${e.message}");
      return {false: "Error!"};
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SingleChildScrollView(
          child: SafeArea(
              child: Container(
        width: double.infinity,
        padding: const EdgeInsets.all(15.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const SizedBox(
              height: 20,
            ),
            Container(
              alignment: Alignment.center,
              child: GlobalText(
                text: "Logo",
                textAlign: TextAlign.center,
                fontSize: 25,
                fontWeight: FontWeight.bold,
                color: GlobalColors.titleColor,
              ),
            ),
            const SizedBox(
              height: 50,
            ),
            GlobalText(
              text: "Let's get started!\nCreate your account",
              textAlign: TextAlign.start,
              fontSize: 15,
              fontWeight: FontWeight.normal,
              color: GlobalColors.titleColor,
            ),
            const SizedBox(
              height: 50,
            ),

            // first name input

            GlobalText(
              text: "First Name",
              textAlign: TextAlign.start,
              fontSize: 15,
              fontWeight: FontWeight.bold,
              color: GlobalColors.titleColor,
            ),
            const SizedBox(
              height: 10,
            ),
            TextFormGlobal(
              controller: _firstNameController,
              isObscured: false,
              text: "Enter First Name",
              textInputType: TextInputType.name,
              onTap: () {},
              prefixIcon: Icon(Icons.person),
            ),

            const SizedBox(
              height: 15,
            ),

            // last name input
            GlobalText(
              text: "Last Name",
              textAlign: TextAlign.start,
              fontSize: 15,
              fontWeight: FontWeight.bold,
              color: GlobalColors.titleColor,
            ),
            const SizedBox(
              height: 10,
            ),
            TextFormGlobal(
              controller: _lastNameController,
              isObscured: false,
              text: "Enter Last Name",
              textInputType: TextInputType.name,
              onTap: () {},
              prefixIcon: Icon(Icons.person),
            ),

            const SizedBox(
              height: 15,
            ),

            // email input
            GlobalText(
              text: "Email",
              textAlign: TextAlign.start,
              fontSize: 15,
              fontWeight: FontWeight.bold,
              color: GlobalColors.titleColor,
            ),
            const SizedBox(
              height: 10,
            ),
            TextFormGlobal(
              controller: _emailController,
              isObscured: false,
              text: "Enter Email",
              textInputType: TextInputType.emailAddress,
              onTap: () {},
              prefixIcon: Icon(Icons.email),
            ),
            const SizedBox(
              height: 15,
            ),

            // password input
            GlobalText(
              text: "Password",
              textAlign: TextAlign.start,
              fontSize: 15,
              fontWeight: FontWeight.bold,
              color: GlobalColors.titleColor,
            ),
            const SizedBox(
              height: 10,
            ),
            TextFormGlobal(
              controller: _passwordController,
              isObscured: true,
              text: "Enter Password",
              textInputType: TextInputType.visiblePassword,
              onTap: () {},
              prefixIcon: Icon(Icons.password),
            ),
            const SizedBox(
              height: 30,
            ),

            // login button
            ButtonGlobal(
              text: "Create Account",
              onTap: register,
            ),
          ],
        ),
      ))),
      // don't have an account?
      bottomNavigationBar: Container(
        height: 50,
        alignment: Alignment.center,
        child: Row(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            GlobalText(
                text: "Have an account?",
                textAlign: TextAlign.end,
                fontSize: 15,
                fontWeight: FontWeight.normal,
                color: GlobalColors.titleColor),
            GestureDetector(
              onTap: widget.onTap,
              child: GlobalText(
                  text: " Sign In",
                  textAlign: TextAlign.end,
                  fontSize: 15,
                  fontWeight: FontWeight.bold,
                  color: GlobalColors.titleColor),
            )
          ],
        ),
      ),
    );
  }
}