package net.micode.notes.tool;

import android.content.Context;
import android.content.SharedPreferences;

/**
 * 用户管理工具类，用于管理用户登录状态
 */
public class UserManager {
    
    private static final String PREF_NAME = "user_prefs";
    private static final String KEY_IS_LOGGED_IN = "is_logged_in";
    private static final String KEY_CURRENT_USER = "current_user";
    
    private static UserManager instance;
    private SharedPreferences sharedPreferences;
    
    private UserManager(Context context) {
        sharedPreferences = context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
    }
    
    public static synchronized UserManager getInstance(Context context) {
        if (instance == null) {
            instance = new UserManager(context.getApplicationContext());
        }
        return instance;
    }
    
    /**
     * 保存登录状态
     */
    public void saveLoginStatus(String username) {
        sharedPreferences.edit()
                .putBoolean(KEY_IS_LOGGED_IN, true)
                .putString(KEY_CURRENT_USER, username)
                .apply();
    }
    
    /**
     * 检查是否已登录
     */
    public boolean isLoggedIn() {
        return sharedPreferences.getBoolean(KEY_IS_LOGGED_IN, false);
    }
    
    /**
     * 获取当前用户名
     */
    public String getCurrentUsername() {
        return sharedPreferences.getString(KEY_CURRENT_USER, "");
    }
    
    /**
     * 退出登录，清除登录状态
     */
    public void logout() {
        sharedPreferences.edit()
                .putBoolean(KEY_IS_LOGGED_IN, false)
                .remove(KEY_CURRENT_USER)
                .apply();
    }
}