package com.moon.server.interceptor;

import com.alibaba.fastjson.JSON;
import com.moon.server.entity.all.HttpStatus;
import com.moon.server.entity.all.ResponseMsg;
import com.moon.server.entity.sys.TokenEntity;
import com.moon.server.entity.sys.UserEntity;
import com.moon.server.helper.StringHelper;
import com.moon.server.helper.WebHelper;
import com.moon.server.service.all.SysService;
import com.moon.server.entity.all.StaticData;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.List;

/**
 * 身份认证拦截器
 * @author WWW
 */
@Configuration
public class AuthInterceptor implements HandlerInterceptor {
    private final SysService sysService;

    private static final Log log = LogFactory.getLog(AuthInterceptor.class);

    public static final String NO_TOKEN = JSON.toJSONString(new ResponseMsg<String>(HttpStatus.TOKEN_ERROR, "找不到令牌"));

    public static final String NO_LOGIN = JSON.toJSONString(new ResponseMsg<String>(HttpStatus.NO_LOGIN_ERROR, "用户未登录"));

    public static final String USER_LOCK = JSON.toJSONString(new ResponseMsg<String>(HttpStatus.USER_LOCK_ERROR, "用户ID已禁用"));

    public static final String NO_AUTH = JSON.toJSONString(new ResponseMsg<String>(HttpStatus.NO_AUTH_ERROR, "无权限访问"));

    public static final String IP_NULL = JSON.toJSONString(new ResponseMsg<String>(HttpStatus.UNAUTHORIZED, "IP地址为空"));

    public static final String BLACK_LIST = JSON.toJSONString(new ResponseMsg<String>(HttpStatus.UNAUTHORIZED, "IP列入黑名单"));

    public static final String ILLEGAL_TOKEN = JSON.toJSONString(new ResponseMsg<String>(HttpStatus.UNAUTHORIZED, "令牌来源非法"));

    public AuthInterceptor(SysService sysService) {
        this.sysService = sysService;
    }

    /**
     * Controller执行之前执行，如果返回值是true则代表放行，返回false则拦截
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
        // noinspection AlibabaRemoveCommentedCode
        try {
            // 1.非方法 或 无需授权，无需拦截
            if (!(handler instanceof HandlerMethod) || noNeedAuth(request)) {
                return true;
            }

            // 2.获取令牌
            String token = WebHelper.getToken(request);
            if (StringHelper.isNull(token)) {
                return WebHelper.writeStr2Page(response, NO_TOKEN);
            }

            // 3.获取用户
            UserEntity ue = sysService.tokenService.getUserByToken(token);
            if (ue == null) {
                return WebHelper.writeStr2Page(response, NO_LOGIN);
            }

            // 4.获取IP
            String ip = WebHelper.getIpAddress(request);
            if (StringHelper.isEmpty(ip)) {
                return WebHelper.writeStr2Page(response, IP_NULL);
            }

            // 5.检查黑名单
            if (!checkBlackList(ip, request)) {
                return WebHelper.writeStr2Page(response, BLACK_LIST);
            }

            // 6.admin跳过权限检测
            if (StaticData.ADMIN.equals(ue.getUid())) {
                return true;
            }

            // 7.检查白名单和IP一致性
            if (!checkWhiteList(ip, request)) {
                if (!checkIpSource(ip, token)) {
                    return WebHelper.writeStr2Page(response, ILLEGAL_TOKEN);
                }
            }

            // 8.检查用户ID是否禁用
            if (sysService.tokenService.isUidDisable(ue)) {
                return WebHelper.writeStr2Page(response, USER_LOCK);
            }

            // 9.权限校验
            if (!checkPerms(ue, request)) {
                System.out.println("无权限访问：" + request.getRequestURI().toLowerCase());
                return WebHelper.writeStr2Page(response, NO_AUTH);
            }

            return true;
        } catch (Exception ex) {
            log.error(ex.getMessage(), ex);
            return false;
        }
    }

    /**
     * 无需授权
     */
    private static boolean noNeedAuth(HttpServletRequest request) {
        String uri = request.getRequestURI().toLowerCase();
        for (String page : StaticData.EXCLUDE_PATH) {
            if (uri.contains(page)) {
                return true;
            }
        }

        return false;
    }

    /**
     * 检查权限
     */
    private boolean checkPerms(UserEntity ue, HttpServletRequest request) {
        List<String> list = sysService.permsService.selectPerms(ue.getUid());
        if (list == null || list.size() == 0) {
            return false;
        }

        String url = request.getRequestURI();
        for (String perm : list) {
            if (url.contains(perm)) {
                return true;
            }
        }

        return false;
    }

    /**
     * 检查黑名单
     */
    private boolean checkBlackList(String ip, HttpServletRequest request) {
        List<String> blackList = sysService.blacklistService.selectIpList(1);
        if (blackList == null || blackList.isEmpty()) {
            return true;
        }
        if (blackList.contains(ip)) {
            return false;
        }

        return true;
    }

    /**
     * 检查白名单
     */
    private boolean checkWhiteList(String ip, HttpServletRequest request) {
        List<String> whiteList = sysService.blacklistService.selectIpList(2);
        if (whiteList == null || whiteList.isEmpty()) {
            return false;
        }

        return whiteList.contains(ip);
    }

    /**
     * 检查IP一致性：固定令牌不检查
     */
    private boolean checkIpSource(String ip, String token) {
        TokenEntity te = sysService.tokenService.getEntityByToken(token);

        return StaticData.I1 == te.getType() || te.getIp().equals(ip);
    }
}