NetAuth/app/src/main/java/me/yoqi/android/netauth/ui/login/LoginViewModel.java

package me.yoqi.android.netauth.ui.login;

import android.util.Patterns;

import androidx.lifecycle.LiveData;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;

import me.yoqi.android.netauth.R;
import me.yoqi.android.netauth.data.LoginRepository;
import me.yoqi.android.netauth.data.Result;
import me.yoqi.android.netauth.data.model.LoggedInUser;

/**
 *
 */
public class LoginViewModel extends ViewModel {

    private final MutableLiveData<LoginFormState> loginFormState = new MutableLiveData<>();
    private final MutableLiveData<LoginResult> loginResult = new MutableLiveData<>();
    private LoginRepository loginRepository;

    LoginViewModel(LoginRepository loginRepository) {
        this.loginRepository = loginRepository;
    }

    /**
     * @return
     */
    LiveData<LoginFormState> getLoginFormState() {
        return loginFormState;
    }

    /**
     * 获取登录结果
     *
     * @return
     */
    LiveData<LoginResult> getLoginResult() {
        return loginResult;
    }

    /**
     * 登录
     *
     * @param username 用户名
     * @param password 密码
     */
    public void login(String username, String password) {
        Result<LoggedInUser> result = loginRepository.login(username, password);

        if (result instanceof Result.Success) {
            LoggedInUser data = ((Result.Success<LoggedInUser>) result).getData();
            loginResult.setValue(new LoginResult(new LoggedInUserView(data.getDisplayName())));
            //登录成功，跳转到 MainActivity

        } else {
            loginResult.setValue(new LoginResult(R.string.login_failed));
        }
    }

    /**
     * 密码框更改事件
     *
     * @param username
     * @param password
     */
    public void loginDataChanged(String username, String password) {
        if (!isUserNameValid(username)) {
            loginFormState.setValue(new LoginFormState(R.string.invalid_username, null));
        } else if (!isPasswordValid(password)) {
            loginFormState.setValue(new LoginFormState(null, R.string.invalid_password));
        } else {
            loginFormState.setValue(new LoginFormState(true));
        }
    }

    // A placeholder username validation check
    private boolean isUserNameValid(String username) {
        if (username == null) {
            return false;
        }
        if (username.contains("@")) {
            return Patterns.EMAIL_ADDRESS.matcher(username).matches();
        } else {
            return !username.trim().isEmpty();
        }
    }

    // A placeholder password validation check
    private boolean isPasswordValid(String password) {
        return password != null && password.trim().length() > 5;
    }
}