package org.mercury_im.messenger.ui.login;

import android.app.Application;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.lifecycle.AndroidViewModel;
import androidx.lifecycle.LiveData;
import androidx.lifecycle.MutableLiveData;

import org.jxmpp.jid.EntityBareJid;
import org.jxmpp.jid.impl.JidCreate;
import org.jxmpp.stringprep.XmppStringprepException;
import org.mercury_im.messenger.MercuryImApplication;
import org.mercury_im.messenger.Messenger;
import org.mercury_im.messenger.R;
import org.mercury_im.messenger.entity.Account;
import org.mercury_im.messenger.entity.IAccount;

import javax.inject.Inject;

import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.schedulers.Schedulers;

public class LoginViewModel extends AndroidViewModel {

    private MutableLiveData<Error> usernameError = new MutableLiveData<>(new Error());
    private MutableLiveData<Error> passwordError = new MutableLiveData<>(new Error());
    private MutableLiveData<Boolean> loginEnabled = new MutableLiveData<>(false);
    private MutableLiveData<Boolean> loginSuccessful = new MutableLiveData<>(false);

    private EntityBareJid username;
    private String password;

    @Inject
    Messenger messenger;

    public LoginViewModel(@NonNull Application application) {
        super(application);
        ((MercuryImApplication) application).getAppComponent().inject(this);
    }

    public void setUsername(String username) {
        if (username == null || username.isEmpty()) {
            usernameError.setValue(new Error(getApplication().getResources().getString(R.string.error_field_required)));
            this.username = null;
            updateLoginEnabled();
            return;
        }

        try {
            this.username = JidCreate.entityBareFrom(username);
            updateLoginEnabled();
        } catch (XmppStringprepException e) {
            usernameError.setValue(new Error(getApplication().getResources().getString(R.string.error_invalid_username)));
            this.username = null;
            updateLoginEnabled();
        }
    }

    public void setPassword(String password) {
        this.password = password;
        updateLoginEnabled();
        if (password == null || password.isEmpty()) {
            passwordError.setValue(new Error(getApplication().getResources().getString(R.string.error_field_required)));
        }
    }

    private void updateLoginEnabled() {
        loginEnabled.setValue(username != null && !(password == null || password.isEmpty()));
    }

    public void login() {
        Account account = new IAccount();
        account.setAddress(username.asUnescapedString());
        account.setPassword(password);
        account.setEnabled(true);
        loginEnabled.setValue(false);
        messenger.addAccount().enableAccountAndLogin(account)
                .subscribeOn(Schedulers.newThread())
                .observeOn(AndroidSchedulers.mainThread())
                .map(result -> {
                    switch (result) {
                        case success:
                            loginSuccessful.setValue(true);
                            break;
                        case credential_error:
                            passwordError.setValue(new Error(getApplication().getResources().getString(R.string.error_incorrect_password)));
                            loginEnabled.setValue(true);
                            break;
                        case server_error:
                        case other_error:
                            Toast.makeText(getApplication(), "A connection error occurred", Toast.LENGTH_LONG);
                            loginEnabled.setValue(true);
                    }
                    return true;
                })
                .ignoreElement()
                .subscribe();
    }

    public LiveData<Error> getPasswordError() {
        return passwordError;
    }

    public LiveData<Error> getUsernameError() {
        return usernameError;
    }

    public LiveData<Boolean> isLoginSuccessful() {
        return loginSuccessful;
    }

    public LiveData<Boolean> isLoginEnabled() {
        return loginEnabled;
    }

    public static class Error {

        private String message;

        public Error() {

        }

        public Error(String errorMessage) {
            this.message = errorMessage;
        }

        public boolean isError() {
            return message != null;
        }

        public String getErrorMessage() {
            return message;
        }
    }
}