/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.apache.skywalking.apm.plugin.jetty.v90.client;

import org.apache.skywalking.apm.agent.core.context.CarrierItem;
import org.apache.skywalking.apm.agent.core.context.ContextCarrier;
import org.apache.skywalking.apm.agent.core.context.ContextManager;
import org.apache.skywalking.apm.agent.core.context.tag.Tags;
import org.apache.skywalking.apm.agent.core.context.trace.AbstractSpan;
import org.apache.skywalking.apm.agent.core.context.trace.SpanLayer;
import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.EnhancedInstance;
import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
import org.apache.skywalking.apm.network.trace.component.ComponentsDefine;
import org.eclipse.jetty.client.HttpRequest;
import org.eclipse.jetty.client.api.Response;
import org.eclipse.jetty.http.HttpFields;
import org.eclipse.jetty.http.HttpMethod;

import java.lang.reflect.Method;

public class AsyncHttpRequestSendInterceptor implements InstanceMethodsAroundInterceptor {
    @Override
    public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
                             MethodInterceptResult result) throws Throwable {
        HttpRequest request = (HttpRequest) objInst;
        ContextCarrier contextCarrier = new ContextCarrier();
        AbstractSpan span = ContextManager.createExitSpan(request.getURI().getPath(), contextCarrier,
                request.getHost() + ":" + request.getPort());
        span.setComponent(ComponentsDefine.JETTY_CLIENT);

        Tags.HTTP.METHOD.set(span, getHttpMethod(request));
        Tags.URL.set(span, request.getURI().toString());
        SpanLayer.asHttp(span);

        CarrierItem next = contextCarrier.items();
        HttpFields field = request.getHeaders();
        while (next.hasNext()) {
            next = next.next();
            field.add(next.getHeadKey(), next.getHeadValue());
        }

        span.prepareForAsync();
        request.attribute(Constants.SW_JETTY_EXIT_SPAN_KEY, span);
        Response.CompleteListener callback = (Response.CompleteListener) allArguments[0];
        allArguments[0] = new CompleteListenerWrapper(callback, ContextManager.capture());
    }

    @Override
    public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
                              Object ret) throws Throwable {
        ContextManager.stopSpan();
        return ret;
    }

    @Override
    public void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments,
                                      Class<?>[] argumentsTypes, Throwable t) {
        ContextManager.activeSpan().log(t);
    }

    private String getHttpMethod(HttpRequest request) {
        HttpMethod httpMethod = HttpMethod.GET;

        /**
         * The method is null if the client using GET method.
         *
         * @see org.eclipse.jetty.client.HttpRequest#GET(String uri)
         * @see org.eclipse.jetty.client.HttpRequest( org.eclipse.jetty.client.HttpClient client, long conversation, java.net.URI uri)
         */
        if (request.getMethod() != null) {
            httpMethod = request.getMethod();
        }

        return httpMethod.name();
    }
}
