/*
 * Copyright 2007-2009 the original author or authors.
 *
 * Licensed 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 net.paoding.rose.web;

import java.lang.reflect.Method;

import net.paoding.rose.web.advancedinterceptor.ActionSelector;
import net.paoding.rose.web.advancedinterceptor.DispatcherSelector;
import net.paoding.rose.web.advancedinterceptor.Named;
import net.paoding.rose.web.advancedinterceptor.Ordered;
import net.paoding.rose.web.impl.thread.AfterCompletion;

import org.springframework.util.Assert;

/**
 * 
 * @author 王志亮 [qieqie.wang@gmail.com]
 * 
 */
public class InterceptorDelegate implements Ordered, Named, ControllerInterceptor, AfterCompletion,
        ActionSelector, DispatcherSelector, Comparable<InterceptorDelegate> {

    protected final ControllerInterceptor interceptor;

    private String name;

    // afterCompletion以及dispatcherSelector判断是每个请求都需要的，所以这里做变量缓存
    private boolean isAfterCompletion;

    private boolean isDispatcherSelector;

    public static ControllerInterceptor getMostInnerInterceptor(ControllerInterceptor interceptor) {
        ControllerInterceptor temp = interceptor;
        while (temp instanceof InterceptorDelegate) {
            temp = ((InterceptorDelegate) temp).getInterceptor();
        }
        return temp;
    }

    public InterceptorDelegate(ControllerInterceptor interceptor) {
        Assert.notNull(interceptor);
        this.interceptor = interceptor;
        this.isAfterCompletion = interceptor instanceof AfterCompletion;
        this.isDispatcherSelector = interceptor instanceof DispatcherSelector;
    }

    public ControllerInterceptor getInterceptor() {
        return interceptor;
    }

    @Override
    public String getName() {
        if (interceptor instanceof Named) {
            name = ((Named) interceptor).getName();
        }
        return name;
    }

    @Override
    public void setName(String name) {
        this.name = name;
        if (interceptor instanceof Named) {
            ((Named) interceptor).setName(name);
        }
    }

    @Override
    public int getPriority() {
        if (interceptor instanceof Ordered) {
            return ((Ordered) interceptor).getPriority();
        }
        return 0;
    }

    @Override
    public boolean isForAction(Class<?> controllerClazz, Method actionMethod) {
        if (interceptor instanceof ActionSelector) {
            return ((ActionSelector) interceptor).isForAction(controllerClazz, actionMethod);
        }
        return true;
    }

    @Override
    public boolean isForDispatcher(Dispatcher dispatcher) {
        if (isDispatcherSelector) {
            return ((DispatcherSelector) interceptor).isForDispatcher(dispatcher);
        }
        return true;
    }

    @Override
    public Object roundInvocation(Invocation inv, InvocationChain chain) throws Exception {
        return interceptor.roundInvocation(inv, chain);
    }

    @Override
    public void afterCompletion(Invocation inv, Throwable ex) throws Exception {
        if (isAfterCompletion) {
            ((AfterCompletion) interceptor).afterCompletion(inv, ex);
        }
    }

    @Override
    public int compareTo(InterceptorDelegate o) {
        if (o == this) {
            return 0;
        }
        // 优先级高，比起来更低
        // !! 不要通过 this.getPriority() - o.getPriority() 来判断，会溢出导致错误Integer.MAX_VALUE - -2000
        if (this.getPriority() > o.getPriority()) {
            return -1;
        }
        if (this.getPriority() < o.getPriority()) {
            return 1;
        }
        // 优先级一样的，按字符串顺序；
        return getName().compareTo(o.getName());
    }

    @Override
    public String toString() {
        return getMostInnerInterceptor(this).getClass().getName();
    }

}