package com.xinquan.gateway.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
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.reactive.function.server.RequestPredicates;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.RouterFunctions;
import com.xinquan.gateway.handler.ValidateCodeHandler;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilter;
import org.springframework.web.server.WebFilterChain;
import reactor.core.publisher.Mono;

/**
 * 路由配置信息
 * 
 * @author ruoyi
 */
@Configuration
public class RouterFunctionConfiguration
{

    /**
     * 这里为支持的请求头，如果有自定义的header字段请自己添加
     */
    private static final String ALLOWED_HEADERS = "X-Requested-With, Content-Type, Authorization, credential, X-XSRF-TOKEN, token, username, client, request-origion";
    private static final String ALLOWED_METHODS = "GET,POST,PUT,DELETE,OPTIONS,HEAD";
    private static final String ALLOWED_ORIGIN = "*";
    private static final String ALLOWED_EXPOSE = "*";
    private static final String MAX_AGE = "18000L";

    @Autowired
    private ValidateCodeHandler validateCodeHandler;

    @SuppressWarnings("rawtypes")
    @Bean
    public RouterFunction routerFunction()
    {
        return RouterFunctions.route(
                RequestPredicates.GET("/code").and(RequestPredicates.accept(MediaType.TEXT_PLAIN)),
                validateCodeHandler);
    }

    /**
     * 跨域配置
     */
    @Bean
    public WebFilter corsFilter()
    {
        return (ServerWebExchange ctx, WebFilterChain chain) -> {
            ServerHttpRequest request = ctx.getRequest();
            if (CorsUtils.isCorsRequest(request))
            {
                ServerHttpResponse response = ctx.getResponse();
                HttpHeaders headers = response.getHeaders();
                headers.add("Access-Control-Allow-Headers", ALLOWED_HEADERS);
                headers.add("Access-Control-Allow-Methods", ALLOWED_METHODS);
                headers.add("Access-Control-Allow-Origin", ALLOWED_ORIGIN);
                headers.add("Access-Control-Expose-Headers", ALLOWED_EXPOSE);
                headers.add("Access-Control-Max-Age", MAX_AGE);
                headers.add("Access-Control-Allow-Credentials", "true");
                if (request.getMethod() == HttpMethod.OPTIONS)
                {
                    response.setStatusCode(HttpStatus.OK);
                    return Mono.empty();
                }
            }
            return chain.filter(ctx);
        };
    }
}