package com.ruoyi.gateway.filter;

import com.ruoyi.gateway.config.properties.AntiShakeProperties;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import com.ruoyi.common.core.constant.CacheConstants;
import com.ruoyi.common.core.constant.HttpStatus;
import com.ruoyi.common.core.constant.SecurityConstants;
import com.ruoyi.common.core.constant.TokenConstants;
import com.ruoyi.common.core.utils.JwtUtils;
import com.ruoyi.common.core.utils.ServletUtils;
import com.ruoyi.common.core.utils.StringUtils;
import com.ruoyi.common.redis.service.RedisService;
import com.ruoyi.gateway.config.properties.IgnoreWhiteProperties;
import io.jsonwebtoken.Claims;
import reactor.core.publisher.Mono;

import java.util.HashMap;
import java.util.Map;


/**
 * 网关鉴权
 *
 * @author ruoyi
 */
@Component
public class AuthFilter implements GlobalFilter, Ordered {
	private static final Logger log = LoggerFactory.getLogger(AuthFilter.class);
	
	// 排除过滤的 uri 地址，nacos自行添加
	@Autowired
	private IgnoreWhiteProperties ignoreWhite;
	@Autowired
	private AntiShakeProperties antiShakeProperties;

	@Autowired
	private RedisService redisService;
	
	
	
	
	@Override
	public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
		ServerHttpRequest request = exchange.getRequest();
		ServerHttpRequest.Builder mutate = request.mutate();
		
		String url = request.getURI().getPath();
		// 跳过不需要验证的路径
		if (StringUtils.matches(url, ignoreWhite.getWhites())) {
			return chain.filter(exchange);
		}
		//防抖校验
		try {
			antiShake(request);
		}catch (Exception e){
			log.error(e.getMessage());
			return ServletUtils.webFluxResponseWriter(exchange.getResponse(), e.getMessage(), HttpStatus.SUCCESS);
		}
		
		//校验账户是否有效
		try {
			verifyToken(request);
		}catch (Exception e){
			return unauthorizedResponse(exchange, e.getMessage());
		}
		String token = getToken(request);
		Claims claims = JwtUtils.parseToken(token);
		String userkey = JwtUtils.getUserKey(claims);
		String userid = JwtUtils.getUserId(claims);
		String username = JwtUtils.getUserName(claims);
		String userType = JwtUtils.getUserType(claims);
		
		// 设置用户信息到请求
		addHeader(mutate, SecurityConstants.USER_KEY, userkey);
		addHeader(mutate, SecurityConstants.DETAILS_USER_ID, userid);
		addHeader(mutate, SecurityConstants.DETAILS_USERNAME, username);
		addHeader(mutate, SecurityConstants.USER_TYPE, userType);
		// 内部请求来源参数清除
		removeHeader(mutate, SecurityConstants.FROM_SOURCE);
		return chain.filter(exchange.mutate().request(mutate.build()).build());
	}
	
	private void addHeader(ServerHttpRequest.Builder mutate, String name, Object value) {
		if (value == null) {
			return;
		}
		String valueStr = value.toString();
		String valueEncode = ServletUtils.urlEncode(valueStr);
		mutate.header(name, valueEncode);
	}
	
	private void removeHeader(ServerHttpRequest.Builder mutate, String name) {
		mutate.headers(httpHeaders -> httpHeaders.remove(name)).build();
	}
	
	private Mono<Void> unauthorizedResponse(ServerWebExchange exchange, String msg) {
		log.error("[鉴权异常处理]请求路径:{}", exchange.getRequest().getPath() + "\n" + msg);
		return ServletUtils.webFluxResponseWriter(exchange.getResponse(), msg, HttpStatus.UNAUTHORIZED);
	}
	
	/**
	 * 获取缓存key
	 */
	private String getTokenKey(String token) {
		return CacheConstants.LOGIN_TOKEN_KEY + token;
	}
	
	/**
	 * 获取请求token
	 */
	private String getToken(ServerHttpRequest request) {
		String token = request.getHeaders().getFirst(TokenConstants.AUTHENTICATION);
		// 如果前端设置了令牌前缀，则裁剪掉前缀
		if (StringUtils.isNotEmpty(token) && token.startsWith(TokenConstants.PREFIX)) {
			token = token.replaceFirst(TokenConstants.PREFIX, StringUtils.EMPTY);
		}
		return token;
	}
	
	
	/**
	 * 防抖处理
	 */
	public void antiShake(ServerHttpRequest request) throws Exception{
		HttpMethod method = request.getMethod();
		if(HttpMethod.OPTIONS == method || !antiShakeProperties.getEnable()){
			return;
		}
		HttpHeaders headers = request.getHeaders();
		String client = headers.getFirst("client");
		String timestamp = headers.getFirst("timestamp");
		if(StringUtils.isEmpty(client)){
			throw new RuntimeException("参数异常");
		}
		if(StringUtils.isEmpty(timestamp)){
			throw new RuntimeException("参数异常");
		}
		String url = request.getURI().getPath();
		Map<String, Object> cacheMap = redisService.getCacheMap(client);
		if(null == cacheMap){
			cacheMap = new HashMap<>();
			cacheMap.put(url, timestamp);
			redisService.setCacheMap(client, cacheMap, 5L);
		}else{
			Object o = cacheMap.get(url);
			if(null == o){
				cacheMap.put(url, timestamp);
			}else{
				Long old_timestamp = Long.valueOf(o.toString());
				Long new_timestamp = Long.valueOf(timestamp);
				//两个请求时间差小于1秒，判定为重复提交
				if((new_timestamp - old_timestamp) <= antiShakeProperties.getInterval()){
					throw new RuntimeException(url + "----->重复提交");
				}else{
					cacheMap.put(url, timestamp);
				}
			}
			redisService.setCacheMap(client, cacheMap, 5L);
		}
	}
	
	
	
	/**
	 * 验证token
	 * @param request
	 * @throws Exception
	 */
	public void verifyToken(ServerHttpRequest request) throws Exception{
		String token = getToken(request);
		if (StringUtils.isEmpty(token)) {
			throw new RuntimeException("令牌不能为空");
		}
		Claims claims = JwtUtils.parseToken(token);
		if (claims == null) {
			throw new RuntimeException("令牌已过期或验证不正确！");
		}
		String userid = JwtUtils.getUserId(claims);
		if (StringUtils.isEmpty(userid)) {
			throw new RuntimeException("令牌验证失败");
		}
	}
	
	
	@Override
	public int getOrder() {
		return -300;
	}
}