/*
    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...
  *
  */