package com.ihooyah.gateway.filter;

import com.alibaba.fastjson.JSONObject;
import com.ihooyah.auth.config.UserAuthConfig;
import com.ihooyah.auth.jwt.UserAuthUtil;
import com.ihooyah.common.context.BaseContextHandler;
import com.ihooyah.common.msg.RespEnum;
import com.ihooyah.common.msg.RespInfo;
import com.ihooyah.common.util.jwt.IJWTInfo;
import com.ihooyah.gateway.handler.SwaggerProvider;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.jetbrains.annotations.NotNull;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

import java.nio.charset.StandardCharsets;
import java.util.List;


@Configuration
@Slf4j
public class AccessGatewayFilter implements GlobalFilter {

    /**
     *  不进行拦截的地址
     */
    @Value("${gate.ignore.startWith}")
    private String startWith;

    @Autowired
    private UserAuthUtil userAuthUtil;

    @Autowired
    private UserAuthConfig userAuthConfig;

    private static final String HEADER_NAME = "X-Forwarded-Prefix";


    @Override
    public Mono<Void> filter(ServerWebExchange serverWebExchange, GatewayFilterChain gatewayFilterChain) {
        log.info("check token and user permission....");
        ServerHttpRequest request = serverWebExchange.getRequest();
        String requestUri = request.getPath().pathWithinApplication().value();

        BaseContextHandler.setToken(null);
        ServerHttpRequest.Builder mutate = request.mutate();
        // 不进行拦截的地址
        if (isStartWith(requestUri)) {
            ServerHttpRequest build = mutate.build();
            return gatewayFilterChain.filter(serverWebExchange.mutate().request(build).build());

        } else if(StringUtils.endsWithIgnoreCase(requestUri, SwaggerProvider.API_URI)){
            /**
             * 对swagger-ui放开
             */
            ServerHttpRequest build = mutate.build();
            return gatewayFilterChain.filter(serverWebExchange.mutate().request(build).build());
        }
        IJWTInfo user;
        try {
            user = getJWTUser(request, mutate);
        } catch (Exception e) {
            log.error("用户Token过期异常", e);
            return getVoidMono(serverWebExchange, new RespInfo(RespEnum.AUTH_ACCESSTOKEN_EXPIRED.getCode(),"User Token Forbidden or Expired!"));
        }
        return gatewayFilterChain.filter(serverWebExchange.mutate().build());

    }

    /**
     * 网关抛异常
     *
     * @param body
     */
    @NotNull
    private Mono<Void> getVoidMono(ServerWebExchange serverWebExchange, RespInfo body) {
        serverWebExchange.getResponse().setStatusCode(HttpStatus.OK);
        byte[] bytes = JSONObject.toJSONString(body).getBytes(StandardCharsets.UTF_8);
        DataBuffer buffer = serverWebExchange.getResponse().bufferFactory().wrap(bytes);
        return serverWebExchange.getResponse().writeWith(Flux.just(buffer));
    }



    /**
     * 返回session中的用户信息
     *
     * @param request
     * @param ctx
     * @return
     */
    private IJWTInfo getJWTUser(ServerHttpRequest request, ServerHttpRequest.Builder ctx) throws Exception {
        List<String> strings = request.getHeaders().get(userAuthConfig.getTokenHeader());
        String authToken = null;
        if (strings != null) {
            authToken = strings.get(0);
        }
        if (StringUtils.isBlank(authToken)) {
            strings = request.getQueryParams().get("token");
            if (strings != null) {
                authToken = strings.get(0);
            }
        }
        ctx.header(userAuthConfig.getTokenHeader(), authToken);
        BaseContextHandler.setToken(authToken);
        return userAuthUtil.getInfoFromToken(authToken);
    }

    /**
     * URI是否以什么打头
     *
     * @param requestUri
     * @return
     */
    private boolean isStartWith(String requestUri) {
        boolean flag = false;
        for (String s : startWith.split(",")) {
            if (requestUri.startsWith(s)) {
                return true;
            }
        }
        return flag;
    }


}
