import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.hhwy.fweb.gateway.constant.GatewayConstant;
import org.apache.commons.codec.Charsets;
import org.reactivestreams.Publisher;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.core.io.buffer.DefaultDataBufferFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.http.server.reactive.ServerHttpResponseDecorator;
import org.springframework.stereotype.Component;
import org.springframework.util.AntPathMatcher;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilter;
import org.springframework.web.server.WebFilterChain;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.netty.http.server.HttpServerResponse;

import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;

/**
 * @author ：PangTiemin
 * @date ：Created in 2021/11/10 13:55
 * @description：
 * @modified By：
 */
@Component
public class RedirectLastFilter implements WebFilter{
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
        AntPathMatcher antPathMatcher = new AntPathMatcher();
       if(!antPathMatcher.match("/*/login/dologin",exchange.getRequest().getPath().value())){
            return chain.filter(exchange);
        }

        ServerHttpResponse originalResponse = exchange.getResponse();
        DataBufferFactory bufferFactory = originalResponse.bufferFactory();
        ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {
            @Override
            public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
                if (body instanceof Flux) {
                    Flux<? extends DataBuffer> fluxBody = (Flux<? extends DataBuffer>) body;
                    return super.writeWith(fluxBody.buffer().map(dataBuffer -> {
                        DataBufferFactory dataBufferFactory = new DefaultDataBufferFactory();
                        DataBuffer join = dataBufferFactory.join(dataBuffer);
                        byte[] content = new byte[join.readableByteCount()];
                        join.read(content);
                        DataBufferUtils.release(join);

                        //responseData 就是响应
                        String responseData = new String(content, Charsets.UTF_8);
                        JSONObject data = JSON.parseObject(responseData);
                        if (data.get("code").equals("10200")){
                            HttpHeaders headers = originalResponse.getHeaders();
//                            headers.remove("Content-Type");
//                            headers.add("Content-Type", "text/javascript");
                            byte[] uppedContent = new String(content, Charset.forName("UTF-8")).getBytes();
                            return bufferFactory.wrap(uppedContent);
                        }else {
                            //s就是response的值
                            byte[] uppedContent = new String(content, Charset.forName("UTF-8")).getBytes();
                            return bufferFactory.wrap(uppedContent);
                        }
                    }));
                }
                // if body is not a flux. never got there.
                return super.writeWith(body);
            }
        };
        // replace response with decorator
        return chain.filter(exchange.mutate().response(decoratedResponse).build());
        }


}