public class LoginActivity extends AppCompatActivity implements View.OnClickListener{

Button buttonSignIn,buttonVentanaRegistrar;
EditText editTextEmail, editTextPass;

public static  String userEmail;

FirebaseAuth.AuthStateListener mAuthListener;

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

    buttonSignIn = (Button) findViewById(R.id.btn_login);
    buttonSignIn.setOnClickListener(this);

    buttonVentanaRegistrar = (Button) findViewById(R.id.btn_ventana_registrar);
    buttonVentanaRegistrar.setOnClickListener(this);

    editTextEmail = (EditText) findViewById(R.id.correo_login);
    editTextPass = (EditText) findViewById(R.id.contraseña_login);


    //CODIGO QUE IMPLEMENTE PARA QUE DE ERROR CUANDO NO SE INGRESA NINGUN DATO
    /*buttonSignIn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(editTextEmail.getText().toString().isEmpty()){
                editTextEmail.setError("Ingrese usuario");
                 }
            if(editTextPass.getText().toString().isEmpty()){
                editTextPass.setError("Ingrese contraseña");
            }

                if (editTextEmail.getText().toString().isEmpty() && editTextPass.getText().toString().isEmpty()){
                    editTextEmail.setError("Ingrese usuario");
                    editTextPass.setError("Ingrese contraseña");
                }
                else{

                }
          }
    });*/




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

            if(user != null){

           //     startActivity(new Intent(LoginActivity.this, CatalogoActivity.class));
             //   finish();
            }else{

                //Log.i("SESION","Sesion cerrada");
            }

        }
    };

}


@Override
public void onClick(View view) {

    switch (view.getId()){
         case R.id.btn_login:
           String email_login = editTextEmail.getText().toString();
            String pass_Login  = editTextPass.getText().toString();
            iniciarSesion(email_login,pass_Login);
              break;


        case R.id.btn_ventana_registrar:
            Intent siguienteVentana = new Intent(getApplicationContext(), RegistroActivity.class);
            startActivity(siguienteVentana);
            break;
    }


}

private void iniciarSesion(String email,String pass){
    userEmail = email;
    FirebaseAuth.getInstance().signInWithEmailAndPassword(email,pass).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
        @Override
        public void onComplete(@NonNull Task<AuthResult> task) {

            if(task.isSuccessful()){
                //mensaje("Inicio de sesion correctamente");
                Intent siguienteVentana = new Intent(getApplicationContext(), CatalogoActivity.class);
                startActivity(siguienteVentana);
            }else{
                mensaje(task.getException().getMessage()+"");
            }

            if(editTextEmail.getText().toString().isEmpty() && editTextPass.getText().toString().isEmpty()){
                editTextEmail.setError("Ingrese usuario");
                editTextPass.setError("Ingrese contraseña");
            }
          }


    });

}



@Override
protected  void onStart() {
    super.onStart();
    FirebaseAuth.getInstance().addAuthStateListener(mAuthListener);
}

@Override
protected  void onStop() {
    super.onStop();
    if(mAuthListener != null){
        FirebaseAuth.getInstance().removeAuthStateListener(mAuthListener);
    }

}

public void mensaje(String mensaje){

    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage(mensaje)
            .setTitle("Mensaje")
            .setCancelable(false)
            .setNeutralButton("Aceptar",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int id) {
                            dialog.cancel();
                        }
                    });
    AlertDialog alert = builder.create();
    alert.show();
}