package jnpf.config;

import org.springframework.cloud.client.discovery.ReactiveDiscoveryClient;
import org.springframework.cloud.gateway.discovery.DiscoveryClientRouteDefinitionLocator;
import org.springframework.cloud.gateway.discovery.DiscoveryLocatorProperties;
import org.springframework.cloud.gateway.route.RouteDefinitionLocator;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.codec.ServerCodecConfigurer;
import org.springframework.http.codec.support.DefaultServerCodecConfigurer;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.cors.reactive.CorsUtils;
import org.springframework.web.server.WebFilter;
import reactor.core.publisher.Mono;

/**
 * 跨域问题
 *
 * @author JNPF开发平台组
 * @version V3.1.0
 * @copyright 引迈信息技术有限公司（https://www.jnpfsoft.com）
 * @date 2021-03-24
 */
@Configuration
public class CorsConfig {
    private static final String ALL = "*";
    private static final String MAX_AGE = "18000L";


    @Bean
    public RouteDefinitionLocator discoveryClientRouteDefinitionLocator(ReactiveDiscoveryClient discoveryClient, DiscoveryLocatorProperties properties) {
        return new DiscoveryClientRouteDefinitionLocator(discoveryClient, properties);
    }


    //AuthFilter的默认顺序是-100  跨域配置在认证之前执行
//    @Bean
//    @Order(-200)
    public WebFilter corsFilter() {
        return (ctx, chain) -> {
            ServerHttpRequest request = ctx.getRequest();
            if (!CorsUtils.isCorsRequest(request)) {
                return chain.filter(ctx);
            }
            HttpHeaders requestHeaders = request.getHeaders();
            ServerHttpResponse response = ctx.getResponse();
            HttpMethod requestMethod = requestHeaders.getAccessControlRequestMethod();
            HttpHeaders headers = response.getHeaders();
            headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_ORIGIN, requestHeaders.getOrigin());
            headers.addAll(HttpHeaders.ACCESS_CONTROL_ALLOW_HEADERS, requestHeaders.getAccessControlRequestHeaders());
            if (requestMethod != null) {
                headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_METHODS, requestMethod.name());
            }
            headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_CREDENTIALS, "true");
            headers.add(HttpHeaders.ACCESS_CONTROL_EXPOSE_HEADERS, ALL);
            headers.add(HttpHeaders.ACCESS_CONTROL_MAX_AGE, MAX_AGE);
            if (request.getMethod() == HttpMethod.OPTIONS) {
                response.setStatusCode(HttpStatus.OK);
                return Mono.empty();
            }
            return chain.filter(ctx);
        };
    }

    @Bean
    public ServerCodecConfigurer serverCodecConfigurer() {
        return new DefaultServerCodecConfigurer();
    }

}