package cn.mb.cloud.gateway.filter;

import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.*;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpRequestDecorator;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;



@Slf4j
@Component
public class WrapperResponseGlobalFilter implements GlobalFilter, Ordered {

    @Override
    public int getOrder() {
        return Ordered.HIGHEST_PRECEDENCE;
    }

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest req = exchange.getRequest();
        ServerHttpResponse res = exchange.getResponse();
        String method = req.getMethodValue();
        MediaType ct = req.getHeaders().getContentType();
        if (HttpMethod.POST.matches(method)) {
            return DataBufferUtils.join(req.getBody()).flatMap(dataBuffer -> {
                byte[] bytes = new byte[dataBuffer.readableByteCount()];
                dataBuffer.read(bytes);
//                String bodyStr = new String(bytes, StandardCharsets.UTF_8);
//                exchange.getAttributes().put("POST_BODY", bodyStr);
                DataBufferUtils.release(dataBuffer);
                Flux<DataBuffer> cachedFlux = Flux.defer(() -> {
                    DataBuffer buffer = res.bufferFactory().wrap(bytes);
                    return Mono.just(buffer);
                });
                ServerHttpRequest mutateReq = new ServerHttpRequestDecorator(req) {
                    @Override
                    public Flux<DataBuffer> getBody() {
                        return cachedFlux;
                    }
                };
                return chain.filter(exchange.mutate().request(mutateReq).build());
            });
        }
        return chain.filter(exchange);
    }

}