private void bindUI(){
        txtEmail = (EditText) findViewById(R.id.txtEmail);
        txtPassword = (EditText) findViewById(R.id.txtPassword);
        swtRecordar = (Switch) findViewById(R.id.swtRecordar);
        btnLogin = (Button) findViewById(R.id.btnLogin);
    }

    private void setCredentialsIfExist() {
        String email = Util.getUserMailPrefs(prefs);
        String password = Util.getUserPassPrefs(prefs);
        boolean recordar = Util.getrecordarPrefs(prefs);
        String strRecordar = Boolean.toString(recordar);
        if(!TextUtils.isEmpty(email) && !TextUtils.isEmpty(password) && TextUtils.equals("true", strRecordar)){
            txtEmail.setText(email);
            txtPassword.setText(password);
            swtRecordar.setChecked(recordar);
        }
    }

    private void removeSharedPreferences(SharedPreferences preferences){
        SharedPreferences.Editor editor = preferences.edit();
        editor.remove("email");
        editor.remove("pass");
        editor.remove("recordar");
        editor.apply();
    }

    private boolean login(String email, String password){
        if(!isValidEmail(email)){
            Toast.makeText(this, "Correo no válido, intente nuevamente", Toast.LENGTH_LONG).show();
            return false;
        } else if(!isValidPassword(password)){
            Toast.makeText(this, "Contraseña muy corta, intente nuevamente", Toast.LENGTH_LONG).show();
            return false;
        } else {
            return true;
        }
    }

    private void saveOnPreferences(String email, String password, boolean recordar){
        if(swtRecordar.isChecked()){
            SharedPreferences.Editor editor = prefs.edit();
            editor.putString("email", email);
            editor.putString("pass", password);
            editor.putBoolean("recordar", recordar);
            editor.commit();
            editor.apply();
        }
    }

    private boolean isValidEmail(String email){
        email.trim();
        return !TextUtils.isEmpty(email) && Patterns.EMAIL_ADDRESS.matcher(email).matches();
    }

    private boolean isValidPassword(String password){
        password.trim();
        return password.length() > 4;
    }

    private void goToMain(){
        Intent intent = new Intent(this, MainActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        startActivity(intent);
    }