package org.gcube.gcat.persistence.ckan;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;

import javax.cache.Cache;
import javax.cache.CacheManager;
import javax.cache.Caching;
import javax.cache.configuration.MutableConfiguration;
import javax.cache.expiry.CreatedExpiryPolicy;
import javax.cache.expiry.Duration;
import javax.cache.spi.CachingProvider;

import org.gcube.gcat.utils.ContextUtility;

public abstract class CKANUserCache {
	
	private static final CacheManager cacheManager;
	
	private static final String USERS_CACHE = "userCache";
	
	private static final MutableConfiguration<String,CKANUser> userCacheConfiguration;
	
	private static final Map<String,Cache<String,CKANUser>> userCachePerContext;
	
	static {
		CachingProvider provider = Caching.getCachingProvider();
		cacheManager = provider.getCacheManager();
		
		userCacheConfiguration = new MutableConfiguration<String,CKANUser>().setTypes(String.class, CKANUser.class)
				.setStoreByValue(false)
				.setExpiryPolicyFactory(CreatedExpiryPolicy.factoryOf(new Duration(TimeUnit.MINUTES, 15)));
		
		userCachePerContext = new HashMap<String,Cache<String,CKANUser>>();
	}
	
	private CKANUserCache() {
	}
	
	public static CKANUser getCurrrentCKANUser() {
		String context = ContextUtility.getCurrentContext();
		Cache<String,CKANUser> userCache = userCachePerContext.get(context);
		if(userCache == null) {
			userCache = cacheManager.createCache(USERS_CACHE, userCacheConfiguration);
			userCachePerContext.put(context, userCache);
		}
		
		String gcubeUsername = ContextUtility.getUsername();
		CKANUser ckanUser = userCache.get(gcubeUsername);
		if(ckanUser == null) {
			ckanUser = new CKANUser();
			ckanUser.retrieve();
			userCache.put(gcubeUsername, ckanUser);
		}
		return ckanUser;
	}
	
	@Override
	protected void finalize() throws Throwable {
		super.finalize();
		cacheManager.close();
	}
	
}