/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

package com.nokia.sdt.emf.dm.impl;

import com.nokia.sdt.emf.dm.*;

import com.nokia.sdt.emf.dm.util.PropertyValueSwitch;

import java.util.*;

public class StringGarbageCollector {

	private Set referencedLocalized = new HashSet();

	private Set referencedMacros = new HashSet();

	private NodeVisitor nodeVisitor = new NodeVisitor();

	private PropertyVisitor propertyVisitor = new PropertyVisitor();

	class NodeVisitor implements INodeVisitor {

		public Object visit(INode node) {

			node.getProperties().visitProperties(propertyVisitor);

			return null;

		}

	}

	class PropertyVisitor implements IPropertyVisitor {

		public Object visit(IPropertyContainer container, EStringToIPropertyValueMapEntryImpl entry) {

			PropertyValueSwitch pvs = new PropertyValueSwitch() {

				@Override

				protected Object handleStringValue(IPropertyValue pv) {

					checkString(pv.getStringValue());

					return null;

				}

				@Override

				protected Object handleCompoundValue(IPropertyValue pv) {

					pv.getCompoundValue().visitProperties(PropertyVisitor.this);

					return null;

				}

				@Override

				protected Object handleSequenceValue(IPropertyValue pv) {

					for (Iterator iter = pv.getSequenceValue().iterator(); iter.hasNext();) {

						IPropertyValue seqPV = (IPropertyValue) iter.next();

						if (seqPV.hasStringValue()) {

							checkString(seqPV.getStringValue());

						} else if (seqPV.hasCompoundValue()) {

							seqPV.getCompoundValue().visitProperties(PropertyVisitor.this);

						}

					}

					return null;

				}

			};

			pvs.doSwitch(entry.getTypedValue());

			return null;

		}

		private void checkString(StringValue sv) {

			int type = sv.getType();

			if (type == StringValue.LOCALIZED) {

				referencedLocalized.add(sv.getValue());

			}

			else if (type == StringValue.MACRO) {

				referencedLocalized.add(sv.getValue());

			}

		}

	}

	public void gc(IDesignerData root) {

		root.visitNodes(nodeVisitor);

		Set unreferenced = new HashSet();

		ILocalizedStringBundle stringBundle = root.getStringBundle();

		if (stringBundle.getLocalizedStringTables().size() > 0) {

			ILocalizedStringTable lst = (ILocalizedStringTable) stringBundle.getLocalizedStringTables().get(0);

			for (Iterator iter = lst.getStrings().keySet().iterator(); iter.hasNext();) {

				Object key = iter.next();

				if (!referencedLocalized.contains(key)) {

					unreferenced.add(key);

				}

			}

			for (Iterator iter = unreferenced.iterator(); iter.hasNext();) {

				String key = (String) iter.next();

				if (!stringBundle.getUserGeneratedStringKeys().contains(key))

					stringBundle.removeLocalizedStringAllLanguages(key);

			}

		}

		unreferenced.clear();

		IMacroStringTable macroTable = root.getMacroTable();

		for (Iterator iter = macroTable.getStringMacros().keySet().iterator(); iter.hasNext();) {

			Object key = iter.next();

			if (!referencedMacros.contains(key) 

				&& !macroTable.getUserGeneratedStringKeys().contains(key)) {

				iter.remove();

			}		

		}

	}

}