/*
 * 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.nutz.mvc;

import java.lang.reflect.Method;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.nutz.mvc.Mvcs;
import org.nutz.mvc.annotation.At;
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;

/**
 * The <code>ActionMethodInterceptor</code> only use the first mapping value.
 *
 * @author wendal
 */
public class ActionMethodInterceptor implements InstanceMethodsAroundInterceptor {
    @Override
    public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
        MethodInterceptResult result) throws Throwable {
        PathMappingCache pathMappingCache = (PathMappingCache)objInst.getSkyWalkingDynamicField();
        String requestURL = pathMappingCache.findPathMapping(method);
        if (requestURL == null) {
            At methodRequestMapping = method.getAnnotation(At.class);
            if (methodRequestMapping.value().length > 0) {
                requestURL = methodRequestMapping.value()[0];
            } else {
                requestURL = "";
            }
            pathMappingCache.addPathMapping(method, requestURL);
            requestURL = pathMappingCache.findPathMapping(method);
        }

        HttpServletRequest request = Mvcs.getReq();
        ContextCarrier contextCarrier = new ContextCarrier();
        CarrierItem next = contextCarrier.items();
        while (next.hasNext()) {
            next = next.next();
            next.setHeadValue(request.getHeader(next.getHeadKey()));
        }
        AbstractSpan span = ContextManager.createEntrySpan(requestURL, contextCarrier);
        Tags.URL.set(span, request.getRequestURL().toString());
        Tags.HTTP.METHOD.set(span, request.getMethod());
        span.setComponent(ComponentsDefine.NUTZ_MVC_ANNOTATION);
        SpanLayer.asHttp(span);
    }

    @Override
    public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
        Object ret) throws Throwable {
        HttpServletResponse response = Mvcs.getResp();

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

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