package xyz.fortern.service;

import org.springframework.lang.NonNull;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import xyz.fortern.dao.SecurityMapper;
import xyz.fortern.dao.UserMapper;
import xyz.fortern.pojo.PermissionKeyValue;
import xyz.fortern.pojo.Security;
import xyz.fortern.pojo.User;

import javax.servlet.http.HttpSession;
import java.util.HashSet;

import static xyz.fortern.bbs.SystemConstant.EMAIL_REGEX;

@Service
public class AccountService {
	
	private final UserMapper userMapper;
	private final SecurityMapper securityMapper;
	private final PasswordEncoder passwordEncoder;
	
	public AccountService(UserMapper userMapper, SecurityMapper securityMapper, PasswordEncoder passwordEncoder) {
		this.userMapper = userMapper;
		this.securityMapper = securityMapper;
		this.passwordEncoder = passwordEncoder;
	}
	
	/**
	 * 通过登录名和密码登录
	 *
	 * @param loginName 登录名，可能是用户名和手机号
	 * @param password  密码
	 * @return 登录结果
	 */
	public int login(String loginName, String password, HttpSession session) {
		String column = EMAIL_REGEX.matcher(loginName).matches() ? "email" : "username";
		var security = securityMapper.selectSecurityInfoByLoginName(loginName, column);
		if (security == null)
			return 0;//用户不存在
		if (security.getLocked())
			return -2;//用户被锁定，不可登录
		if (passwordEncoder.matches(password, security.getPassword())) {
			int userId = security.getUserId();
			//如果密码匹配
			//获取用户基本信息
			var user = userMapper.selectById(userId);
			//设置权限信息
			var authorities = new HashSet<GrantedAuthority>();
			for (PermissionKeyValue permission : PermissionKeyValue.values()) {
				if ((permission.value ^ security.getPermissions()) == permission.value) {
					authorities.add(new SimpleGrantedAuthority(permission.name));
				}
			}
			if (security.getPosition() == Security.Position.MANAGER)
				authorities.add(new SimpleGrantedAuthority("manager"));
			var authenticationToken = new UsernamePasswordAuthenticationToken(userId, null, authorities);
			//将认证成功信息设置到安全上下文中
			SecurityContextHolder.getContext().setAuthentication(authenticationToken);
			//用户相关信息放入Session中
			session.setAttribute("user", user);
			session.setAttribute("security", security);
			return 1;//登录成功
		} else {
			return -1;//密码错误
		}
	}
	
	/**
	 * 注册业务
	 *
	 * @param username 用户名
	 * @param password 密码
	 * @param email    电子邮箱
	 * @param qqNumber QQ号
	 */
	@Transactional
	public void register(String username, String password, String email, String qqNumber) {
		//先存用户，获取用户id
		var user = User.builder().username(username).email(email).qqNumber(qqNumber).build();
		userMapper.insert(user);
		//再存安全信息
		var security = Security.builder().password(passwordEncoder.encode(password)).userId(user.getId()).build();
		securityMapper.insert(security);
	}
	
	/**
	 * 修改密码
	 *
	 * @param uid         用户id
	 * @param newPassword 新密码（明文）
	 */
	@Transactional
	public Security changePassword(int uid, String newPassword) {
		var security = Security.builder().userId(uid).password(passwordEncoder.encode(newPassword)).build();
		securityMapper.updateById(security);
		return securityMapper.selectSecurityInfoByLoginName(Integer.toString(uid), "user_id");
	}
	
	/**
	 * 检验密码是否正确
	 *
	 * @param oldPassword        旧密码（明文）
	 * @param encodedOldPassword 旧密码（密文）
	 */
	public boolean passwordMatches(@NonNull String oldPassword, @NonNull String encodedOldPassword) {
		return passwordEncoder.matches(oldPassword, encodedOldPassword);
	}
	
}