package jnpf.handler;

import jnpf.util.JsonUtil;
import jnpf.base.ActionResult;
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.web.server.ResponseStatusException;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

/**
 * 网关统一异常处理
 *
 * @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
 */
@Slf4j
@Order(-1)
@Configuration
public class GatewayHandler implements ErrorWebExceptionHandler {

    @Override
    public Mono<Void> handle(ServerWebExchange exchange, 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(ex.getMessage(), ex);
        }

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

        return response.writeWith(Mono.fromSupplier(() -> {
            DataBufferFactory bufferFactory = response.bufferFactory();
            ActionResult result = ActionResult.fail(msg);
            return bufferFactory.wrap(JsonUtil.getObjectToString(result).getBytes());
        }));
    }
}