package net.roarsoftware.lastfm.cache;



import java.util.HashSet;

import java.util.Map;

import java.util.Set;



/**

 * This Policy maintains a list of methods which should be cached one week. Everything else won't be cached if

 * using this policy.

 *

 * @author Janni Kovacs

 */

public class DefaultExpirationPolicy implements ExpirationPolicy {





	/**

	 * One day in milliseconds

	 */

	protected static final long ONE_DAY = 1000 * 60 * 60 * 24;



	/**

	 * One week in milliseconds

	 */

	protected static final long ONE_WEEK = ONE_DAY * 7;



	/**

	 * Contains method names for all requests that should be cached 1 week

	 */

	protected static final Set<String> ONE_WEEK_METHODS = new HashSet<String>();



	static {

		// similar data

		ONE_WEEK_METHODS.add("artist.getsimilar");

		ONE_WEEK_METHODS.add("tag.getsimilar");

		ONE_WEEK_METHODS.add("track.getsimilar");

		// top chart data

		ONE_WEEK_METHODS.add("artist.gettopalbums");

		ONE_WEEK_METHODS.add("artist.gettoptracks");

		ONE_WEEK_METHODS.add("geo.gettopartists");

		ONE_WEEK_METHODS.add("geo.gettoptracks");

		ONE_WEEK_METHODS.add("tag.gettopalbums");

		ONE_WEEK_METHODS.add("tag.gettopartists");

		ONE_WEEK_METHODS.add("tag.gettoptags");

		ONE_WEEK_METHODS.add("tag.gettoptracks");

		ONE_WEEK_METHODS.add("user.gettopalbums");

		ONE_WEEK_METHODS.add("user.gettopartists");

		ONE_WEEK_METHODS.add("user.gettoptracks");

		ONE_WEEK_METHODS.add("user.gettoptags");

	}



	/**

	 * Contains the expiration time for weekly chart data for the current week, which is

	 * one week by default; last.fm TOS says:

	 * "You agree to cache similar artist and any chart data (top tracks, top artists, top albums) for a minimum of one week."

	 * but they might be outdated the next day.

	 * For now we will cache them one week. If you always need the latest charts but don't want to disable

	 * caching use the {@link #setCacheRecentWeeklyCharts(long)} method to set this value.

	 * This variable also applies to the getWeeklyChartList method

	 */

	protected long cacheRecentWeeklyCharts = ONE_WEEK;



	public long getExpirationTime(String method, Map<String, String> params) {

		method = method.toLowerCase();

		if (method.contains("weekly")) {

			if (!method.contains("list"))

				return params.containsKey("to") && params

						.containsKey("from") ? Long.MAX_VALUE : cacheRecentWeeklyCharts;

			else

				return cacheRecentWeeklyCharts;

		}

		return ONE_WEEK_METHODS.contains(method) ? ONE_WEEK : -1;

	}



	public void setCacheRecentWeeklyCharts(long cacheRecentWeeklyCharts) {

		this.cacheRecentWeeklyCharts = cacheRecentWeeklyCharts;

	}

}