Verification.java

package org.colibrisoft.colibri;

import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.FirebaseException;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseAuthInvalidCredentialsException;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.auth.PhoneAuthCredential;
import com.google.firebase.auth.PhoneAuthProvider;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.iid.FirebaseInstanceId;

import java.util.HashMap;
import java.util.concurrent.TimeUnit;



public class Verification extends AppCompatActivity {

    //These are the objects needed
    //It is the verification id that will be sent to the user
    private String mVerificationId;

    //The edittext to input the code
    private EditText editTextCode;

    //firebase auth object
    private FirebaseAuth mAuth;

    private TextView mCodeError;
    protected Button verify_button;
    protected TextView user_phone;
    protected String PhoneVal;
    protected EditText send_code;
    private DatabaseReference mDatabase;
    private DatabaseReference mUserDatabase;

    private String UserNameVal;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_verification);

        //initializing objects
        mAuth = FirebaseAuth.getInstance();
        editTextCode = findViewById(R.id.send_code);
        mCodeError = (TextView) findViewById(R.id.code_error);
        user_phone=findViewById(R.id.user_phone);
        PhoneVal=getIntent().getExtras().getString("Value");
        user_phone.setText(PhoneVal);
        verify_button= findViewById(R.id.verify_button);
        UserNameVal = getIntent().getExtras().getString("UserName");


        mUserDatabase = FirebaseDatabase.getInstance().getReference().child("Users");

        //getting mobile number from the previous activity
        //and sending the verification code to the number
        sendVerificationCode(PhoneVal);


        //if the automatic sms detection did not work, user can also enter the code manually
        //so adding a click listener to the button
        findViewById(R.id.verify_button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String code = editTextCode.getText().toString().trim();
                if (code.isEmpty()) {

                    editTextCode.setError("Enter valid code");
                    editTextCode.requestFocus();

                    return;
                }
                //verifying the code entered manually
                verifyVerificationCode(code);
            }
        });

    }

    //the method is sending verification code
    //the country id is concatenated
    //you can take the country id as user input as well
    private void sendVerificationCode(String PhoneVal) {
        PhoneAuthProvider.getInstance().verifyPhoneNumber(
                PhoneVal,
                60,
                TimeUnit.SECONDS,
                this,
                mCallbacks);
    }


    //the callback to detect the verification status
    private PhoneAuthProvider.OnVerificationStateChangedCallbacks
            mCallbacks = new PhoneAuthProvider.OnVerificationStateChangedCallbacks() {
        @Override
        public void onVerificationCompleted(PhoneAuthCredential phoneAuthCredential) {

            //Getting the code sent by SMS
            String code = phoneAuthCredential.getSmsCode();

            //sometime the code is not detected automatically
            //in this case the code will be null
            //so user has to manually enter the code
            if (code != null) {
                editTextCode.setText(code);
                //verifying the code
                verifyVerificationCode(code);
            }
        }

        @Override
        public void onVerificationFailed(FirebaseException e) {
            Toast.makeText(Verification.this, e.getMessage(), Toast.LENGTH_LONG).show();
        }

        @Override
        public void onCodeSent(String s, PhoneAuthProvider.ForceResendingToken forceResendingToken) {
            super.onCodeSent(s, forceResendingToken);

            //storing the verification id that is sent to the user
            mVerificationId = s;
        }
    };


    private void verifyVerificationCode(String code) {
        //creating the credential
        PhoneAuthCredential credential = PhoneAuthProvider.getCredential(mVerificationId, code);

        //signing the user
        signInWithPhoneAuthCredential(credential);
    }

    private void signInWithPhoneAuthCredential(PhoneAuthCredential credential) {
        mAuth.signInWithCredential(credential)
                .addOnCompleteListener(Verification.this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {


                            FirebaseUser current_user = FirebaseAuth.getInstance().getCurrentUser();
                            String uid = current_user.getUid();
                            mDatabase = FirebaseDatabase.getInstance().getReference().child("Users").child(uid);



                            String deviceToken = FirebaseInstanceId.getInstance().getToken();

                            HashMap<String, String> userMap = new HashMap<>();
                            userMap.put("phone", PhoneVal);
                            userMap.put("name", UserNameVal);
                            userMap.put("status", "Hi there, I'm using Colibri Messenger!" );
                            userMap.put("image", "default");
                            userMap.put("thumb_image", "default");
                            userMap.put("device_token", deviceToken);

                            mDatabase.setValue(userMap).addOnCompleteListener(new OnCompleteListener<Void>() {
                                @Override
                                public void onComplete(@NonNull Task<Void> task) {
                                    if (task.isSuccessful()){

                                        Intent intent = new Intent(Verification.this, HomePage.class);
                                        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
                                        //intent.putExtra("Phone_Val", PhoneVal);
                                        //intent.putExtra("Name_Val", UserNameVal);
                                        startActivity(intent);
                                        finish();
                                    }
                                }
                            });
                            //verification successful we will start the profile activity

                        } else {

                            //verification unsuccessful.. display an error message

                            Toast.makeText(Verification.this, "Something is wrong, we will fix it soon...", Toast.LENGTH_SHORT).show();

                            if (task.getException() instanceof FirebaseAuthInvalidCredentialsException) {
                                send_code.setError("Enter valid code");
                            }

                        }
                    }
                });
    }
}