package com.lxzn.auth;

import com.lxzn.auth.security.UserJwt;
import lombok.extern.slf4j.Slf4j;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContext;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;

@Slf4j
public class SpringSecurityUtils {
    /**
     * 取得Authentication, 如当前SecurityContext为空时返回null.
     */
    public static Authentication getAuthentication() {
        SecurityContext context = SecurityContextHolder.getContext();
        if(context == null)
            return null;
        return context.getAuthentication();
    }

    public static <T extends UserDetails> T getCurrentUser() {
        Authentication authentication = getAuthentication();
        if (authentication == null) {
            return null;
        }
        Object principal = authentication.getPrincipal();
        if (!(principal instanceof UserDetails)) {
            return null;
        }
        return (T) principal;
    }

    /**
     * 取得当前用户的id，如果当前用户与未登录，则返回null.
     */
    public static String getCurrentUserId() {
        UserJwt springSecurityUserAuth = getCurrentUser();
        if (springSecurityUserAuth == null) {
            return null;
        }
        return springSecurityUserAuth.getUserId();
    }

    /**
     * 取得当前用户的id，如果当前用户与未登录，则返回null.
     */
    public static String getCurrentUsername() {
        UserJwt springSecurityUserAuth = getCurrentUser();
        if (springSecurityUserAuth == null) {
            return null;
        }
        return springSecurityUserAuth.getUsername();
    }
}