package com.inspur.smsb.gateway.handler;

import com.alibaba.cola.dto.Response;
import com.alibaba.fastjson.JSON;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.web.reactive.error.ErrorWebExceptionHandler;
import org.springframework.cloud.gateway.support.NotFoundException;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.lang.NonNull;
import org.springframework.web.server.ResponseStatusException;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

/**
 * 网关统一异常处理
 *
 * @author liangke
 */
@Slf4j
@Configuration
@Order(-1)
@RequiredArgsConstructor
public class GatewayExceptionHandler implements ErrorWebExceptionHandler {
    /**
     * @param exchange exchange
     * @param ex       ex
     * @return Mono<Void>
     */
    @NonNull
    @Override
    public Mono<Void> handle(ServerWebExchange exchange, @NonNull Throwable ex) {
        ServerHttpResponse response = exchange.getResponse();

        if (exchange.getResponse().isCommitted()) {
            return Mono.error(ex);
        }

        String msg;

        if (ex instanceof NotFoundException) {
            msg = "服务未找到";
        } else if (ex instanceof ResponseStatusException) {
            ResponseStatusException responseStatusException = (ResponseStatusException) ex;
            msg = responseStatusException.getMessage();
        } else {
            msg = "内部服务器错误";
        }

        log.error("[网关异常处理]请求方法：{}，请求路径: {}，异常信息: {}", exchange.getRequest().getMethod(), exchange.getRequest().getPath(), ex.getMessage());

        response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
        response.setStatusCode(HttpStatus.OK);

        return response.writeWith(Mono.fromSupplier(() -> {
            DataBufferFactory bufferFactory = response.bufferFactory();
            return bufferFactory.wrap(JSON.toJSONBytes(Response.buildFailure("500", msg)));
        }));
    }
}