public class AuthFragment extends Fragment {

    private AutoCompleteTextView mEmail;
    private EditText mPassword;
    private Button mEnter;
    private Button mRegister;
    private SharedPreferencesHelper mSharedPreferencesHelper;

    private ArrayAdapter<String> mEmailedUsersAdapter;

    public static AuthFragment newInstance() {
        Bundle args = new Bundle();

        AuthFragment fragment = new AuthFragment();
        fragment.setArguments(args);
        return fragment;
    }

    private View.OnClickListener mOnEnterClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (isEmailValid() && isPasswordValid()) {
                User user = mSharedPreferencesHelper.login(
                        mEmail.getText().toString(),
                        mPassword.getText().toString());
                if (user != null) {
                    Intent startProfileIntent =
                            new Intent(getActivity(), ProfileActivity.class);
                    startProfileIntent.putExtra(ProfileActivity.USER_KEY, user);
                    startActivity(startProfileIntent);
                    getActivity().finish();
                } else {
                    showMessage(R.string.login_error);
                }
            } else {
                showMessage(R.string.input_error);
            }

//            for (User user : mSharedPreferencesHelper.getUsers()) {
//                if (user.getEmail().equalsIgnoreCase(mEmail.getText().toString())
//                        && user.getPassword().equals(mPassword.getText().toString())) {
//                    break;
//                }
//            }

        }
    };

    private View.OnClickListener mOnRegisterClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            getFragmentManager()
                    .beginTransaction()
                    .replace(R.id.fragmentContainer, RegistrationFragment.newInstance())
                    .addToBackStack(RegistrationFragment.class.getName())
                    .commit();
        }
    };

//    private View.OnFocusChangeListener mOnLoginFocusChangeListener = new View.OnFocusChangeListener() {
//        @Override
//        public void onFocusChange(View view, boolean hasFocus) {
//            if (hasFocus) {
//                mEmail.showDropDown();
//            }
//        }
//    };

    private boolean isEmailValid() {
        return !TextUtils.isEmpty(mEmail.getText())
                && Patterns.EMAIL_ADDRESS.matcher(mEmail.getText()).matches();
    }

    private boolean isPasswordValid() {
        return !TextUtils.isEmpty(mPassword.getText());
    }

    private void showMessage(@StringRes int string) {
        Toast.makeText(getActivity(), string, Toast.LENGTH_LONG).show();
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fr_auth, container, false);

        mSharedPreferencesHelper = new SharedPreferencesHelper(getActivity());

        mEmail = v.findViewById(R.id.etLogin);
        mPassword = v.findViewById(R.id.etPassword);
        mEnter = v.findViewById(R.id.buttonEnter);
        mRegister = v.findViewById(R.id.buttonRegister);

        mEnter.setOnClickListener(mOnEnterClickListener);
        mRegister.setOnClickListener(mOnRegisterClickListener);
    //    mEmail.setOnFocusChangeListener(mOnLoginFocusChangeListener);

        mEmailedUsersAdapter = new ArrayAdapter<>(
                getActivity(),
                android.R.layout.simple_dropdown_item_1line,
                mSharedPreferencesHelper.getSuccessLogins()
        );
        mEmail.setAdapter(mEmailedUsersAdapter);

        return v;
    }
}