package com.student.service;

import com.student.bean.LoginLog;
import com.student.bean.RememberToken;
import com.student.bean.User;
import com.student.dao.LogDao;
import com.student.dao.RememberTokenDao;
import com.student.dao.UserDao;
import com.student.dao.impl.LogDaoImpl;
import com.student.dao.impl.RememberTokenDaoImpl;
import com.student.dao.impl.UserDaoImpl;
import com.student.util.PasswordUtil;

import java.util.Calendar;
import java.util.Date;

public class AuthService {

    private static final int MAX_FAIL_COUNT = 5;
    private static final int LOCK_MINUTES = 30;
    private static final int REMEMBER_DAYS = 7;

    private final UserDao userDao;
    private final LogDao logDao;
    private final RememberTokenDao tokenDao;

    public AuthService() {
        this(new UserDaoImpl(), new LogDaoImpl(), new RememberTokenDaoImpl());
    }

    AuthService(UserDao userDao, LogDao logDao, RememberTokenDao tokenDao) {
        this.userDao = userDao;
        this.logDao = logDao;
        this.tokenDao = tokenDao;
    }

    public User login(String username, String password, String ip) {
        User user = userDao.findByUsername(username);
        if (user == null) {
            saveLoginLog(null, username, ip, 0, "用户不存在");
            return null;
        }
        if (isLocked(user)) {
            saveLoginLog(user.getId(), username, ip, 0, "账户已锁定");
            throw new RuntimeException("账户已锁定，请稍后再试");
        }
        if (!PasswordUtil.verify(password, user.getSalt(), user.getPassword())) {
            int failCount = (user.getFailCount() != null ? user.getFailCount() : 0) + 1;
            userDao.updateFailCount(user.getId(), failCount);
            if (failCount >= MAX_FAIL_COUNT) {
                Calendar cal = Calendar.getInstance();
                cal.add(Calendar.MINUTE, LOCK_MINUTES);
                userDao.lockUser(user.getId(), cal.getTime());
                saveLoginLog(user.getId(), username, ip, 0, "密码错误，账户已锁定");
                throw new RuntimeException("密码错误次数过多，账户已锁定30分钟");
            }
            saveLoginLog(user.getId(), username, ip, 0, "密码错误");
            return null;
        }
        if (user.getStatus() != null && user.getStatus() == User.STATUS_PENDING) {
            saveLoginLog(user.getId(), username, ip, 0, "账户待审核");
            throw new RuntimeException("账户待审核，请等待管理员审批");
        }
        if (user.getStatus() != null && (user.getStatus() == User.STATUS_SUSPEND
                || user.getStatus() == User.STATUS_DROPPED)) {
            saveLoginLog(user.getId(), username, ip, 0, "账户已停用");
            throw new RuntimeException("账户已停用");
        }
        userDao.updateFailCount(user.getId(), 0);
        userDao.lockUser(user.getId(), null);
        saveLoginLog(user.getId(), username, ip, 1, "登录成功");
        user.setPassword(null);
        return user;
    }

    public String createRememberToken(int userId) {
        tokenDao.deleteByUser(userId);
        RememberToken token = new RememberToken();
        token.setUserId(userId);
        token.setToken(PasswordUtil.generateToken());
        Calendar cal = Calendar.getInstance();
        cal.add(Calendar.DAY_OF_MONTH, REMEMBER_DAYS);
        token.setExpireTime(cal.getTime());
        tokenDao.save(token);
        return token.getToken();
    }

    public User loginByToken(String token) {
        RememberToken rt = tokenDao.findByToken(token);
        if (rt == null) {
            return null;
        }
        User user = userDao.findById(rt.getUserId());
        if (user != null) {
            user.setPassword(null);
        }
        return user;
    }

    public void logoutRemember(int userId) {
        tokenDao.deleteByUser(userId);
    }

    public void cleanExpiredTokens() {
        tokenDao.deleteExpired();
    }

    private boolean isLocked(User user) {
        if (user.getLockUntil() == null) {
            return false;
        }
        return user.getLockUntil().after(new Date());
    }

    private void saveLoginLog(Integer userId, String username, String ip, int result, String message) {
        LoginLog log = new LoginLog();
        log.setUserId(userId);
        log.setUsername(username);
        log.setIp(ip);
        log.setResult(result);
        log.setMessage(message);
        logDao.saveLoginLog(log);
    }
}