MultiAUth Provider

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:ecommerce/widgets_common/custom_textfield.dart';
import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';

import '../../consts/colors.dart';

class PhoneInputScreen extends StatefulWidget {
  @override
  _PhoneInputScreenState createState() => _PhoneInputScreenState();
}

class _PhoneInputScreenState extends State<PhoneInputScreen> {
  final _phoneNumberController = TextEditingController();

  Future<void> verifyPhoneNumber(BuildContext context) async {
    await FirebaseAuth.instance.verifyPhoneNumber(
      phoneNumber: _phoneNumberController.text,
      verificationCompleted: (PhoneAuthCredential credential) {
        // This callback will be called when auto-retrieval completes
        // For example, auto sign-in (not implemented in this basic example)
      },
      verificationFailed: (FirebaseAuthException e) {
        // Handle verification failure
        print('Verification Failed: ${e.message}');
      },
      codeSent: (String verificationId, int? resendToken) {
        // Navigate to the OTP screen with verificationId
        Navigator.push(
          context,
          MaterialPageRoute(
            builder: (context) => OTPScreen(verificationId),
          ),
        );
      },
      codeAutoRetrievalTimeout: (String verificationId) {},
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: redColor,

      appBar: AppBar(
        title: Text('Phone Number Verification'),
      ),
      body: Padding(
        padding: EdgeInsets.all(20.0),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: [
            TextField(
              controller: _phoneNumberController,
              keyboardType: TextInputType.phone,
              decoration: InputDecoration(labelText: 'Enter Phone Number'),
            ),
            SizedBox(height: 20),
            ElevatedButton(
              onPressed: () => verifyPhoneNumber(context),
              child: Text('Send OTP'),
            ),
          ],
        ),
      ),
    );
  }
}




class OTPScreen extends StatefulWidget {
  final String verificationId;

  OTPScreen(this.verificationId);

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

class _OTPScreenState extends State<OTPScreen> {
  final _otpController = TextEditingController();

  Future<void> signInWithOTP(String smsCode) async {

    try {
      PhoneAuthCredential phoneAuthCredential = PhoneAuthProvider.credential(
        verificationId: widget.verificationId,
        smsCode: smsCode,
      );
      await FirebaseAuth.instance.signInWithCredential(phoneAuthCredential);

      DocumentReference documentReference = FirebaseFirestore.instance.collection('Users').doc(FirebaseAuth.instance.currentUser?.uid);
      DocumentSnapshot snapshot = await documentReference.get();
      if (snapshot.exists) {
        Navigator.pushReplacement(
          context,
          MaterialPageRoute(builder: (context) => HomeScreenZ()),
        );
      } else {

        Navigator.pushReplacement(
          context,
          MaterialPageRoute(builder: (context) => ProfileData()),
        );

      }

    } catch (e) {
      // Handle OTP verification failure
      print('Failed to verify OTP: $e');
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: redColor,
      appBar: AppBar(
        title: Text('Enter OTP'),
      ),
      body: Padding(
        padding: EdgeInsets.all(20.0),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: [
            TextField(
              controller: _otpController,
              keyboardType: TextInputType.number,
              decoration: InputDecoration(labelText: 'Enter OTP'),
            ),
            SizedBox(height: 20),
            ElevatedButton(
              onPressed: () => signInWithOTP(_otpController.text),
              child: Text('Verify OTP'),
            ),
          ],
        ),
      ),
    );
  }
}


class ProfileData extends StatefulWidget {
  const ProfileData({super.key});

  @override
  State<ProfileData> createState() => _ProfileDataState();
}

class _ProfileDataState extends State<ProfileData> {
  TextEditingController _nameController = TextEditingController();
  TextEditingController _emailController = TextEditingController();
  TextEditingController _passwordController = TextEditingController();
  TextEditingController _rePasswordController = TextEditingController();
  User? user = FirebaseAuth.instance.currentUser;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: redColor,
      appBar: AppBar(
        title: Text('Complete Profile'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text('${FirebaseAuth.instance.currentUser?.uid}'),

            TextField(
              controller: _nameController,
              keyboardType: TextInputType.text,
              decoration: InputDecoration(labelText: 'Enter Name'),
            ),
            TextField(
              controller: _emailController,
              keyboardType: TextInputType.emailAddress,
              decoration: InputDecoration(labelText: 'Enter Email'),
            ),
            TextField(
              controller: _passwordController,
              keyboardType: TextInputType.text,
              decoration: InputDecoration(labelText: 'Enter Password'),
            ),
            TextField(
              controller: _rePasswordController,
              keyboardType: TextInputType.text,
              decoration: InputDecoration(labelText: 'Enter Password Again'),
            ),

            ElevatedButton(
                onPressed: () async {
                 
                  

                  final credential = await EmailAuthProvider.credential(email: _emailController.text, password: _passwordController.text);
                  try {
                    final userCredential = await FirebaseAuth.instance.currentUser?.linkWithCredential(credential);
                    await FirebaseFirestore.instance.collection('Users').doc(FirebaseAuth.instance.currentUser?.uid).set({
                      'Uid' : FirebaseAuth.instance.currentUser?.uid,
                      'Email' : _emailController.text,
                      'Password' : _passwordController.text,
                      'Name' : _nameController.text
                    });
                    Navigator.pushReplacement(
                      context,
                      MaterialPageRoute(builder: (context) => HomeScreenZ()),
                    );
                  } on FirebaseAuthException catch (e) {
                    switch (e.code) {
                      case "provider-already-linked":
                        print("The provider has already been linked to the user.");
                        break;
                      case "invalid-credential":
                        print("The provider's credential is not valid.");
                        break;
                      case "credential-already-in-use":
                        print("The account corresponding to the credential already exists, "
                            "or is already linked to a Firebase User.");
                        break;
                    // See the API reference for the full list of error codes.
                      default:
                        print("Unknown error.");
                    }
                  }


                },
                child: Text('Submit'),
            )

          ],
        ),
      ),
    );
  }
}




class HomeScreenZ extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: redColor,
      appBar: AppBar(
        title: Text('Home'),
      ),
      body: Center(
        child: Text('Welcome to the Home Screen!'),
      ),
    );
  }
}