/**
 *
 */

package org.gcube.datatransfer.resolver.caches;

import java.util.concurrent.TimeUnit;

import org.gcube.datatransfer.resolver.applicationprofile.ApplicationProfileReader;
import org.gcube.datatransfer.resolver.listeners.UriResolverStartupListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;

/**
 * The Class GisViewerApplicationHostnameGuavaCache.
 *
 * @author Francesco Mangiacrapa at ISTI-CNR (francesco.mangiacrapa@isti.cnr.it)
 * Nov 2, 2018
 */
public class GisViewerApplicationHostnameGuavaCache {

	private static Logger logger = LoggerFactory.getLogger(GisViewerApplicationHostnameGuavaCache.class);
	private static LoadingCache<String, String> gisViewerApplicationURLCache;

	static {
		gisViewerApplicationURLCache =
			CacheBuilder.newBuilder().maximumSize(100).expireAfterWrite(
				1, TimeUnit.HOURS).build(
				new CacheLoader<String, String>() {

					@Override
					public String load(String scope)
						throws Exception {

						return loadGisViewerApplicationURL(scope);
					}
				});

		logger.info(GisViewerApplicationHostnameGuavaCache.class.getSimpleName() +" instancied");
	}


	/**
	 * Gets the cache.
	 *
	 * @return the cache
	 */
	public static LoadingCache<String, String> getCache() {

		return gisViewerApplicationURLCache;
	}


	/**
	 * Load gis viewer application url.
	 *
	 * @param scope the scope
	 * @return the string
	 */
	public static String loadGisViewerApplicationURL(String scope){

		if (scope == null || scope.isEmpty())
			logger.warn("Scope is null or ermpty, skipping loadGisViewerApplicationURL");

		ApplicationProfileReader reader = new ApplicationProfileReader(scope, UriResolverStartupListener.getGisViewerProfile().getGenericResource(), UriResolverStartupListener.getGisViewerProfile().getAppId(), false);
		String url = reader.getApplicationProfile().getUrl();
		logger.info("With scope "+scope+" loaded the GisViewer Application URL "+url);
		return url;

	}
}