/*
 * 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.resin.v3;

import com.caucho.server.connection.CauchoRequest;
import com.caucho.server.http.HttpResponse;
import java.lang.reflect.Method;
import org.apache.skywalking.apm.agent.core.context.ContextCarrier;
import org.apache.skywalking.apm.agent.core.context.tag.Tags;
import org.apache.skywalking.apm.agent.core.context.CarrierItem;
import org.apache.skywalking.apm.agent.core.context.ContextManager;
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;

/**
 * {@link ResinV3Interceptor} intercept method of{@link com.caucho.server.dispatch.ServletInvocation#service(javax.servlet.ServletRequest,
 * javax.servlet.ServletResponse)} record the resin host, port ,url.
 *
 * @author baiyang
 */
public class ResinV3Interceptor implements InstanceMethodsAroundInterceptor {

    @Override public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes, MethodInterceptResult result) throws Throwable {
        CauchoRequest request = (CauchoRequest)allArguments[0];
        ContextCarrier contextCarrier = new ContextCarrier();
        CarrierItem next = contextCarrier.items();
        while (next.hasNext()) {
            next = next.next();
            next.setHeadValue(request.getHeader(next.getHeadKey()));
        }

        AbstractSpan span = ContextManager.createEntrySpan(request.getPageURI(), contextCarrier);
        span.setComponent(ComponentsDefine.RESIN);
        Tags.URL.set(span, appendRequestURL(request));
        SpanLayer.asHttp(span);
    }

    @Override public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments,
        Class<?>[] argumentsTypes, Object ret) throws Throwable {
        HttpResponse response = (HttpResponse)allArguments[1];
        AbstractSpan span = ContextManager.activeSpan();

        if (response.getStatusCode() >= 400) {
            Tags.STATUS_CODE.set(span, Integer.toString(response.getStatusCode()));
            span.errorOccurred();
        }
        ContextManager.stopSpan();
        return ret;
    }

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

    /**
     * Append request URL.
     *
     * @param request
     * @return
     */
    private String appendRequestURL(CauchoRequest request) {
        StringBuffer sb = new StringBuffer();
        sb.append(request.getScheme());
        sb.append("://");
        sb.append(request.getServerName());
        sb.append(":");
        sb.append(request.getServerPort());
        sb.append(request.getPageURI());
        return sb.toString();
    }
}
