/*
 Wotonomy: OpenStep design patterns for pure Java applications.
 Copyright (C) 2001 Michael Powers

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 This library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, see http://www.gnu.org
 */
package net.wotonomy.access;

import java.util.Enumeration;

import net.wotonomy.control.EOEnterpriseObject;
import net.wotonomy.control.EOGlobalID;
import net.wotonomy.foundation.NSArray;
import net.wotonomy.foundation.NSDictionary;
import net.wotonomy.foundation.NSMutableArray;
import net.wotonomy.foundation.NSMutableDictionary;
import net.wotonomy.foundation.NSTimestamp;

/**
 *
 * @author ezamudio@nasoft.com
 * @author $Author: cgruber $
 * @version $Revision: 894 $
 */
public class EODatabase {

	protected EOAdaptor _adaptor;
	protected NSMutableArray _models = new NSMutableArray();
	protected NSMutableArray _contexts = new NSMutableArray();
	protected NSMutableDictionary _resultCache = new NSMutableDictionary();
	protected NSMutableDictionary _snapshots = new NSMutableDictionary();
	protected NSTimestamp _timestamp;
	protected static boolean _releaseUnrefSnapshots = true;

	public EODatabase(EOAdaptor adaptor) {
		super();
		if (adaptor == null)
			throw new IllegalArgumentException("Adaptor cannot be null.");
		_adaptor = adaptor;
	}

	public EODatabase(EOModel model) {
		super();
		_adaptor = EOAdaptor.adaptorWithModel(model);
		addModel(model);
	}

	public EOAdaptor adaptor() {
		return _adaptor;
	}

	public void addModel(EOModel model) {
		if (!addModelIfCompatible(model))
			throw new IllegalArgumentException("Model is not compatible with this database.");
	}

	public void removeMode(EOModel model) {
		_models.removeObject(model);
	}

	public boolean addModelIfCompatible(EOModel model) {
		if (_models.containsObject(model))
			return false;
		if (model.adaptorName().equals(adaptor().name())) {
			if (adaptor().canServiceModel(model)) {
				_models.addObject(model);
				return true;
			}
		}
		return false;
	}

	public void decrementSnapshotCountForGlobalID(EOGlobalID gid) {
		if (_releaseUnrefSnapshots) {
		}
	}

	public void incrementSnapshotCountForGlobalID(EOGlobalID gid) {
		if (_releaseUnrefSnapshots) {
		}
	}

	public static void disableSnapshotRefCounting() {
		_releaseUnrefSnapshots = false;
	}

	public EOEntity entityForObject(EOEnterpriseObject eo) {
		String cname = eo.getClass().getName();
		for (int i = 0; i < _models.count(); i++) {
			EOModel m = (EOModel) _models.objectAtIndex(i);
			NSArray ents = m.entities();
			for (int j = 0; j < ents.count(); j++) {
				EOEntity e = (EOEntity) ents.objectAtIndex(i);
				if (e.className().equals(cname))
					return e;
			}
		}
		return null;
	}

	public EOEntity entityNamed(String name) {
		for (int i = 0; i < _models.count(); i++) {
			EOModel m = (EOModel) _models.objectAtIndex(i);
			NSArray ents = m.entities();
			for (int j = 0; j < ents.count(); j++) {
				EOEntity e = (EOEntity) ents.objectAtIndex(i);
				if (e.name().equals(name))
					return e;
			}
		}
		return null;
	}

	public void forgetAllSnapshots() {
		_snapshots.removeAllObjects();
	}

	public void forgetSnapshotForGlobalID(EOGlobalID gid) {
		_snapshots.removeObjectForKey(gid);
	}

	public void forgetSnapshotsForGlobalIDs(NSArray gids) {
		for (int i = 0; i < gids.count(); i++)
			forgetSnapshotForGlobalID((EOGlobalID) gids.objectAtIndex(i));
	}

	public void handleDroppedConnection() {
		adaptor().handleDroppedConnection();
		for (int i = 0; i < _contexts.count(); i++) {
			EODatabaseContext c = (EODatabaseContext) _contexts.objectAtIndex(i);
			c.handleDroppedConnection();
		}
	}

	public void invalidateResultCache() {
		_resultCache.removeAllObjects();
	}

	public void invalidateResultCacheForEntityNamed(String name) {
		_resultCache.removeObjectForKey(name);
	}

	public NSArray models() {
		return new NSArray(_models);
	}

	public void recordSnapshotForGlobalID(NSDictionary snap, EOGlobalID gid) {
		_snapshots.setObjectForKey(snap, gid);
	}

	public void recordSnapshotForSourceGlobalID(NSArray gids, EOGlobalID gid, String name) {
		NSMutableDictionary d = (NSMutableDictionary) _snapshots.objectForKey(gid);
		if (d == null) {
			d = new NSMutableDictionary();
			_snapshots.setObjectForKey(d, gid);
		}
		d.setObjectForKey(gids, name);
	}

	public void recordSnapshots(NSDictionary snaps) {
		_snapshots.addEntriesFromDictionary(snaps);
	}

	public void recordToManySnapshots(NSDictionary snaps) {
		Enumeration enumeration = snaps.keyEnumerator();
		while (enumeration.hasMoreElements()) {
			EOGlobalID gid = (EOGlobalID) enumeration.nextElement();
			NSDictionary rels = (NSDictionary) snaps.objectForKey(gid);
			Enumeration relEnum = rels.keyEnumerator();
			while (relEnum.hasMoreElements()) {
				String relName = (String) relEnum.nextElement();
				NSArray gids = (NSArray) rels.objectForKey(relName);
				recordSnapshotForSourceGlobalID(gids, gid, relName);
			}
		}
	}

	public void registerContext(EODatabaseContext context) {
		if (!_contexts.contains(context)) {
			if (context.database() != this)
				throw new IllegalStateException("Cannot register context assigned to a different database.");
			_contexts.addObject(context);
		}
	}

	public void unregisterContext(EODatabaseContext context) {
		_contexts.removeObject(context);
	}

	public NSArray registeredContexts() {
		return new NSArray(_contexts);
	}

	public NSArray resultCacheForEntityNamed(String name) {
		return (NSArray) _resultCache.objectForKey(name);
	}

	public void setResultCache(NSArray cache, String entityName) {
		_resultCache.setObjectForKey(cache, entityName);
	}

	public void setTimestampToNow() {
		_timestamp = new NSTimestamp();
	}

	public NSDictionary snapshotForGlobalID(EOGlobalID gid) {
		return (NSDictionary) _snapshots.objectForKey(gid);
	}

	public NSDictionary snapshotForGlobalID(EOGlobalID gid, long l) {
		return null;
	}

	public NSArray snapshotForSourceGlobalID(EOGlobalID gid, String name) {
		NSDictionary d = (NSDictionary) _snapshots.objectForKey(gid);
		if (d == null)
			return null;
		return (NSArray) d.objectForKey(name);
	}

	public NSDictionary snapshotForSourceGlobalID(EOGlobalID gid, String s, long l) {
		return null;
	}

	public NSDictionary snapshots() {
		return _snapshots;
	}

	public long timestampForGlobalID(EOGlobalID gid) {
		return NSTimestamp.DistantPast.timeIntervalSinceReferenceDate();
	}

	public long timestampForSourceGlobalID(EOGlobalID gid, String s) {
		return 0;
	}

}
/*
 * $Log$ Revision 1.2 2006/02/16 16:47:13 cgruber Move some classes in to
 * "internal" packages and re-work imports, etc.
 *
 * Also use UnsupportedOperationExceptions where appropriate, instead of
 * WotonomyExceptions.
 *
 * Revision 1.1 2006/02/16 13:19:57 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.2 2005/05/11 15:21:53 cgruber Change enum to enumeration, since
 * enum is now a keyword as of Java 5.0
 *
 * A few other comments in the code.
 *
 * Revision 1.1 2003/08/19 01:54:43 chochos The EODatabase layer still needs a
 * lot of work, but it's on its way...
 *
 */