public class DriverLoginActivity extends AppCompatActivity {
private EditText mEmail, mPassword;
private Button mLogin, mRegistration;

private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener firebaseAuthListener;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_driver_login);



    mAuth = FirebaseAuth.getInstance();

    firebaseAuthListener = new FirebaseAuth.AuthStateListener() {
        @Override
        public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
            FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();



            if(user!=null){
                Intent intent = new Intent(DriverLoginActivity.this, MapActivity.class);
                startActivity(intent);
                finish();
                return;
            }
        }
    };



    mEmail = (EditText) findViewById(R.id.email);
    mPassword = (EditText) findViewById(R.id.password);




    mLogin = (Button) findViewById(R.id.login);
    mRegistration = (Button) findViewById(R.id.registration);




    mRegistration.setOnClickListener(new View.OnClickListener() {



        @Override
        public void onClick(View v) {



            if (mEmail.getText().toString().trim().length()< 0)
                if (mPassword.getText().toString().trim().length()< 0);

            final String email = mEmail.getText().toString();
            final String password = mPassword.getText().toString();










            mAuth.createUserWithEmailAndPassword(email, password).addOnCompleteListener(DriverLoginActivity.this, new OnCompleteListener<AuthResult>() {



                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {



                    if(!task.isSuccessful() ){
                        Toast.makeText(DriverLoginActivity.this, "sign up error", Toast.LENGTH_SHORT).show();



                    }else{
                        String user_id = mAuth.getCurrentUser().getUid();
                        DatabaseReference current_user_db = FirebaseDatabase.getInstance().getReference().child("Users").child("Riders").child(user_id);
                        current_user_db.setValue(true);
                    }


                }
            });
        }
    });

    mLogin.setOnClickListener(new View.OnClickListener() {


        @Override
        public void onClick(View v) {

            final String email = mEmail.getText().toString();
            final String password = mPassword.getText().toString();




            mAuth.signInWithEmailAndPassword(email, password).addOnCompleteListener(DriverLoginActivity.this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {


                    if(!task.isSuccessful()){
                        Toast.makeText(DriverLoginActivity.this, "sign in error", Toast.LENGTH_SHORT).show();
                    }
                }
            });

        }
    });
}


@Override
protected void onStart() {
    super.onStart();
    mAuth.addAuthStateListener(firebaseAuthListener);
}
@Override
protected void onStop() {
    super.onStop();
    mAuth.removeAuthStateListener(firebaseAuthListener);
}