package com.moon.server.service.sys;

import com.alibaba.fastjson.JSON;
import com.moon.server.entity.all.*;
import com.moon.server.entity.sys.ResEntity;
import com.moon.server.entity.sys.ResLogEntity;
import com.moon.server.entity.sys.UserEntity;
import com.moon.server.helper.AsyncHelper;
import com.moon.server.helper.HttpHelper;
import com.moon.server.helper.StringHelper;
import com.moon.server.helper.WebHelper;
import com.moon.server.interceptor.AuthInterceptor;
import com.moon.server.service.all.PermsService;
import com.moon.server.service.all.RedisService;
import com.moon.server.service.all.SysService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.List;
import java.util.TimerTask;
import java.util.concurrent.TimeUnit;

/**
 * 代理服务类
 * @author WWW
 * @date 2023-07-11
 */
@Service
public class ProxyService {
    @Resource
    RedisService redisService;

    @Resource
    private SysService sysService;

    @Resource
    private PermsService permsService;

    @Resource
    private ResLogService resLogService;

    public static final String ILLEGAL_RESOURCE = JSON.toJSONString(new ResponseMsg<String>(HttpStatus.UNAUTHORIZED, "没有资源访问权限"));

    /**
     * URL代理
     */
    public void proxyUrl(String token, int resId, boolean isRest, HttpServletRequest req, HttpServletResponse res) throws Exception {
        // 3.获取用户
        UserEntity ue = getUser(req, res, token);
        if (null == ue) {
            return;
        }
        // 9.获取资源实体，status：0-禁用，1-启用原始地址，2-启用代理地址
        ResEntity entity = getResEntity(ue, resId);
        if (null == entity || StaticData.I2 != entity.getStatus() || StringHelper.isNull(entity.getProxy()) || StringHelper.isNull(entity.getUrl())) {
            WebHelper.writeStr2Page(res, ILLEGAL_RESOURCE);
            return;
        }
        insertLog(req, ue, resId);

        String url = getUrl(req, ue, entity, token, isRest);
        res.setHeader("token", token);
        forward(req, res, entity, url);
    }

    /**
     * 获取用户
     */
    private UserEntity getUser(HttpServletRequest req, HttpServletResponse res, String token) {
        String key = RedisCacheKey.permsProxy(token);
        Object obj = redisService.get(key);
        if (obj instanceof UserEntity) {
            return (UserEntity) obj;
        }

        UserEntity ue = sysService.tokenService.getUserByToken(token);
        if (null == ue) {
            WebHelper.writeStr2Page(res, AuthInterceptor.NO_LOGIN);
            return null;
        }
        if (!check(req, res, ue, token)) {
            return null;
        }

        redisService.put(key, ue, SettingData.CACHE_EXPIRE, TimeUnit.MINUTES);

        return ue;
    }

    /**
     * 检查
     */
    private boolean check(HttpServletRequest req, HttpServletResponse res, UserEntity ue, String token) {
        // 4.获取IP
        String ip = WebHelper.getIpAddress(req);
        if (StringHelper.isEmpty(ip)) {
            return WebHelper.writeStr2Page(res, AuthInterceptor.IP_NULL);
        }
        // 5.检查黑名单
        if (!checkBlackList(ip, req)) {
            return WebHelper.writeStr2Page(res, AuthInterceptor.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, req)) {
            if (!ip.equals(sysService.tokenService.getEntityByToken(token).getIp())) {
                return WebHelper.writeStr2Page(res, AuthInterceptor.ILLEGAL_TOKEN);
            }
        }
        // 8.检查用户ID是否禁用
        if (sysService.tokenService.isUidDisable(ue)) {
            return WebHelper.writeStr2Page(res, AuthInterceptor.USER_LOCK);
        }

        return true;
    }

    /**
     * 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;
        }

        return !blackList.contains(ip);
    }

    /**
     * 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);
    }

    /**
     * 检查资源权限
     */
    private ResEntity getResEntity(UserEntity ue, int resId) {
        List<ResEntity> rs = StaticData.ADMIN.equals(ue.getUid()) ? permsService.selectAllRes() : permsService.selectRes(ue.getUid());
        if (null == rs || rs.isEmpty()) {
            return null;
        }
        // List<ResEntity> list = rs.stream().filter(resEntity -> resEntity.getId() == resId).collect(Collectors.toList())
        for (ResEntity entity : rs) {
            if (resId == entity.getId()) {
                return entity;
            }
        }

        return null;
    }

    /**
     * 插入日志
     */
    private void insertLog(HttpServletRequest req, UserEntity ue, int resId) {
        String ip = WebHelper.getIpAddress(req);

        ResLogEntity entity = new ResLogEntity();
        entity.setResid(resId);
        entity.setType(getRequestType(req.getMethod()));
        entity.setIp(ip);
        entity.setUrl(req.getRequestURL().toString());
        entity.setCreateUser(ue.getId());

        AsyncHelper helper = new AsyncHelper();
        helper.execute(new TimerTask() {
            @Override
            public void run() {
                resLogService.insert(entity);
            }
        });
    }

    /**
     * 获取请求类别
     */
    private int getRequestType(String method) {
        // 请求类：1-GET，2-POST，3-PUT，4-DELETE，5-TRACE，6-HEAD，7-OPTIONS，8-CONNECT';
        switch (method) {
            case "GET":
                return 1;
            case "POST":
                return 2;
            case "PUT":
                return 3;
            case "DELETE":
                return 4;
            case "TRACE":
                return 5;
            case "HEAD":
                return 6;
            case "OPTIONS":
                return 7;
            case "CONNECT":
                return 8;
            default:
                return -1;
        }
    }

    /**
     * 获取Url
     */
    private String getUrl(HttpServletRequest req, UserEntity ue, ResEntity entity, String token, boolean isRest) {
        String proxyUrl = entity.getProxy().replace("{token}", token);
        int end = req.getRequestURL().indexOf(proxyUrl) + proxyUrl.length();

        String url = entity.getUrl() + req.getRequestURL().substring(end);
        // category：0-其他，1-GisServer，2-GeoServer，3-数简
        if (StaticData.I2 == entity.getCategory()) {
            url = getGeoServerUrl(req, ue, entity, url);
        } else if (StaticData.I3 == entity.getCategory()) {
            if (null != req.getQueryString()) {
                url = url + (url.contains("?") ? "&" : "?") + req.getQueryString();
            }
            if (isRest) {
                url = url.replace("/v6/wmts/", "/v6/rest/");
            }
            if (!StringHelper.isNull(entity.getArgs())) {
                url = url + (url.contains("?") ? "&" : "?") + entity.getArgs();
            }
        }

        return url;
    }

    /**
     * 获取GeoServer地址
     */
    private String getGeoServerUrl(HttpServletRequest req, UserEntity ue, ResEntity entity, String url) {
        if (null == req.getQueryString()) {
            return url;
        }

        String str = req.getQueryString(), layers = req.getParameter("layers");
        if (!StaticData.GET_CAPABILITIES.equals(req.getParameter(StaticData.REQUEST)) && null != layers) {
            int start = str.indexOf("layers");
            int end = str.indexOf("&", start);
            layers = filterGeoLayers(ue, layers);

            str = str.replace(str.substring(start, end > -1 ? end : str.length()), "layers=" + layers);
        } else {
            entity.setBak(StaticData.GET_CAPABILITIES);
        }

        return url + (url.contains("?") ? "&" : "?") + str;
    }

    /**
     * 过滤GeoServer图层
     */
    private String filterGeoLayers(UserEntity ue, String layers) {
        List<String> tabs = StaticData.ADMIN.equals(ue.getUid()) ? permsService.selectAllTabs() : permsService.selectTabs(ue.getUid());
        if (null == tabs || tabs.isEmpty()) {
            return "";
        }

        StringBuilder sb = new StringBuilder();
        String[] strs = layers.split(StaticData.COMMA);
        for (String str : strs) {
            if (tabs.contains(str)) {
                sb.append(str).append(",");
            }
        }
        sb.deleteCharAt(sb.length() - 1);

        return sb.toString();
    }

    /**
     * 转发请求
     */
    private void forward(HttpServletRequest request, HttpServletResponse response, ResEntity entity, String url) throws Exception {
        HttpHelper httpHelper = new HttpHelper();
        httpHelper.service(request, response, entity, url);
    }
}