// 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 com.cloud.event;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import org.apache.cloudstack.context.CallContext;

import com.cloud.utils.component.ComponentMethodInterceptor;

public class ActionEventInterceptor implements ComponentMethodInterceptor {

	public ActionEventInterceptor() {
	}

	@Override
    public Object interceptStart(Method method, Object target) {
        EventVO event = null;
        for ( ActionEvent actionEvent : getActionEvents(method) ) {
            boolean async = actionEvent.async();
            if(async){
                CallContext ctx = CallContext.current();
                
                String eventDescription = getEventDescription(actionEvent, ctx);
                String eventType = getEventType(actionEvent, ctx);
                
                ActionEventUtils.onStartedActionEventFromContext(eventType, eventDescription);
            }
        }
        return event;
    }

	@Override
    public void interceptComplete(Method method, Object target, Object event) {
	    for ( ActionEvent actionEvent : getActionEvents(method) ) {
            CallContext ctx = CallContext.current();
            long userId = ctx.getCallingUserId();
            long accountId = ctx.getCallingAccountId();
            long startEventId = ctx.getStartEventId();
            String eventDescription = getEventDescription(actionEvent, ctx);
            String eventType = getEventType(actionEvent, ctx);
            
            if ( eventType.equals("") )
                return;
            
            if(actionEvent.create()){
                //This start event has to be used for subsequent events of this action
                startEventId = ActionEventUtils.onCreatedActionEvent(userId, accountId, EventVO.LEVEL_INFO, eventType, "Successfully created entity for "+eventDescription);
                ctx.setStartEventId(startEventId);
            } else {
                ActionEventUtils.onCompletedActionEvent(userId, accountId, EventVO.LEVEL_INFO, eventType, "Successfully completed "+eventDescription, startEventId);
            }
        }
    }

	@Override
    public void interceptException(Method method, Object target, Object event) {
	    for ( ActionEvent actionEvent : getActionEvents(method) ) {
            CallContext ctx = CallContext.current();
            long userId = ctx.getCallingUserId();
            long accountId = ctx.getCallingAccountId();
            long startEventId = ctx.getStartEventId();
            String eventDescription = getEventDescription(actionEvent, ctx);
            String eventType = getEventType(actionEvent, ctx);
            
            if ( eventType.equals("") )
                return;
            
            if(actionEvent.create()){
                long eventId = ActionEventUtils.onCreatedActionEvent(userId, accountId, EventVO.LEVEL_ERROR, eventType, "Error while creating entity for "+eventDescription);
                ctx.setStartEventId(eventId);
            } else {
                ActionEventUtils.onCompletedActionEvent(userId, accountId, EventVO.LEVEL_ERROR, eventType, "Error while "+eventDescription, startEventId);
            }
        }
    }
	
	@Override
	public boolean needToIntercept(Method method) {
        ActionEvent actionEvent = method.getAnnotation(ActionEvent.class);
        if (actionEvent != null) {
            return true;
        }
        
        ActionEvents events = method.getAnnotation(ActionEvents.class);
        if ( events != null ) {
            return true;
        }
        
        return false;
    }
	
	protected List<ActionEvent> getActionEvents(Method m) {
	    List<ActionEvent> result = new ArrayList<ActionEvent>();
	    
	    ActionEvents events = m.getAnnotation(ActionEvents.class);
	    
	    if ( events != null ) {
	        for ( ActionEvent e : events.value() ) {
	            result.add(e);
	        }
	    }
	    
	    ActionEvent e = m.getAnnotation(ActionEvent.class);
	    
	    if ( e != null ) {
	        result.add(e);
	    }
	    
	    return result;
	}
	protected String getEventType(ActionEvent actionEvent, CallContext ctx) {
	    String type = ctx.getEventType();
	    
	    return type == null ? actionEvent.eventType() : type;
	}
	
	protected String getEventDescription(ActionEvent actionEvent, CallContext ctx) {
	    String eventDescription = ctx.getEventDescription();
	    if ( eventDescription == null ) {
	        eventDescription = actionEvent.eventDescription();
	    }
	    
        if(ctx.getEventDetails() != null){
            eventDescription += ". "+ctx.getEventDetails();
        }
        
        return eventDescription;
	}
}