/**
 * Copyright (c) 2011-2012, James Zhan 詹波 (jfinal@126.com).
 *
 * 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 com.jfinal.plugin.ehcache;

import java.util.List;
import com.jfinal.log.Logger;
import net.sf.ehcache.Cache;
import net.sf.ehcache.CacheManager;
import net.sf.ehcache.Element;

/**
 * CacheKit. Useful tool box for EhCache.
 */
public class CacheKit {
	
	private static volatile CacheManager cacheManager;
	private static final Logger log = Logger.getLogger(CacheKit.class);
	
	static void init(CacheManager cacheManager) {
		CacheKit.cacheManager = cacheManager;
	}
	
	public static CacheManager getCacheManager() {
		return cacheManager;
	}
	
	static Cache getOrAddCache(String cacheName) {
		Cache cache = cacheManager.getCache(cacheName);
		if (cache == null) {
			synchronized(cacheManager) {
				cache = cacheManager.getCache(cacheName);
				if (cache == null) {
					log.warn("Could not find cache config [" + cacheName + "], using default.");
					cacheManager.addCacheIfAbsent(cacheName);
					cache = cacheManager.getCache(cacheName);
					log.debug("Cache [" + cacheName + "] started.");
				}
			}
		}
		return cache;
	}
	
	public static void put(String cacheName, Object key, Object value) {
		getOrAddCache(cacheName).put(new Element(key, value));
	}
	
	@SuppressWarnings("unchecked")
	public static <T> T get(String cacheName, Object key) {
		Element element = getOrAddCache(cacheName).get(key);
		return element != null ? (T)element.getObjectValue() : null;
	}
	
	@SuppressWarnings("rawtypes")
	public static List getKeys(String cacheName) {
		return getOrAddCache(cacheName).getKeys();
	}
	
	public static void remove(String cacheName, Object key) {
		getOrAddCache(cacheName).remove(key);
	}
	
	public static void removeAll(String cacheName) {
		getOrAddCache(cacheName).removeAll();
	}
	
	@SuppressWarnings("unchecked")
	public static <T> T handle(String cacheName, Object key, IDataLoader dataLoader) {
		Object data = get(cacheName, key);
		if (data == null) {
			data = dataLoader.load();
			put(cacheName, key, data);
		}
		return (T)data;
	}
}