/**
 * Copyright (c) 2013 itemis AG and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Mark Broerkens - initial API and implementation
 * 
 */
package org.eclipse.rmf.serialization;

import java.util.Collection;
import java.util.Map;

import org.eclipse.emf.common.notify.Notification;
import org.eclipse.emf.common.util.EList;
import org.eclipse.emf.common.util.TreeIterator;
import org.eclipse.emf.ecore.EAttribute;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EPackage;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.util.EContentAdapter;
import org.eclipse.emf.ecore.util.EcoreUtil;

public class IdAdapter extends EContentAdapter {
	final Map<String, EObject> idToEObjectMap;
	final Map<EObject, String> eObjectToIDMap;
	final Collection<EPackage> createIdForPackages;

	public IdAdapter(Map<String, EObject> idToEObjectMap, Map<EObject, String> eObjectToIDMap, Collection<EPackage> createIdForPackages) {
		super();
		this.idToEObjectMap = idToEObjectMap;
		this.eObjectToIDMap = eObjectToIDMap;
		this.createIdForPackages = createIdForPackages;
	}

	@Override
	public boolean isAdapterForType(Object type) {
		// TODO Auto-generated method stub
		return super.isAdapterForType(type);
	}

	@Override
	public void notifyChanged(Notification n) {
		assert null != n.getNotifier();
		super.notifyChanged(n); // the superclass handles adding/removing this Adapter to new Books

		Object notifier_ = n.getNotifier();
		if (!n.isTouch()) {
			if (notifier_ instanceof EObject) {
				Object feature = n.getFeature();
				if (feature instanceof EAttribute) {
					// handle changed id
					EAttribute attribute = (EAttribute) feature;
					if (attribute.isID()) {
						String newId = n.getNewStringValue();
						String oldId = n.getOldStringValue();
						EObject objectWithId = (EObject) n.getNotifier();
						switch (n.getEventType()) {
						case Notification.SET:
							if (null == newId) {
								eObjectToIDMap.remove(objectWithId);
							} else {
								eObjectToIDMap.put(objectWithId, newId);
								idToEObjectMap.put(newId, objectWithId);
							}

							if (null != oldId) {
								idToEObjectMap.remove(oldId);
							}
							break;
						case Notification.UNSET:
							eObjectToIDMap.remove(objectWithId);
							idToEObjectMap.remove(oldId);
							break;
						}
					}
				} else {
					// handle removed or added objects
					EReference reference = (EReference) feature;
					if (reference.isContainment()) {

						switch (n.getEventType()) {
						case Notification.SET:
						case Notification.ADD:
							handleNewObjectAndSubObjects((EObject) n.getNewValue());
							break;
						case Notification.ADD_MANY:
							EList<EObject> newObjects = (EList<EObject>) n.getNewValue();
							int size = newObjects.size();
							for (int i = 0; i < size; i++) {
								handleNewObjectAndSubObjects(newObjects.get(i));
							}
							break;
						case Notification.UNSET:
						case Notification.REMOVE:
							handleRemoveObjectAndSubObjects((EObject) n.getOldValue());
							break;
						case Notification.REMOVE_MANY:
							EList<EObject> removeObjects = (EList<EObject>) n.getOldValue();
							size = removeObjects.size();
							for (int i = 0; i < size; i++) {
								handleRemoveObjectAndSubObjects(removeObjects.get(i));
							}
							break;
						}

					}
				}

			} else if (notifier_ instanceof Resource) {
				// feature is null
				int featureID = n.getFeatureID(Resource.class);
				if (Resource.RESOURCE__CONTENTS == featureID) {
					switch (n.getEventType()) {
					case Notification.SET:
					case Notification.ADD:
						handleNewObjectAndSubObjects((EObject) n.getNewValue());
						break;
					case Notification.ADD_MANY:
						EList<EObject> newObjects = (EList<EObject>) n.getNewValue();
						int size = newObjects.size();
						for (int i = 0; i < size; i++) {
							handleNewObjectAndSubObjects(newObjects.get(i));
						}
						break;
					case Notification.UNSET:
					case Notification.REMOVE:
						handleRemoveObjectAndSubObjects((EObject) n.getOldValue());
						break;
					case Notification.REMOVE_MANY:
						EList<EObject> removeObjects = (EList<EObject>) n.getOldValue();
						size = removeObjects.size();
						for (int i = 0; i < size; i++) {
							handleRemoveObjectAndSubObjects(removeObjects.get(i));
						}
						break;
					}
				}
			} else if (notifier_ instanceof ResourceSet) {
				// NOP
			} else {
				// NOP
			}

		} // end if isTouch

	}// end notifyChanged

	void handleNewObjectAndSubObjects(EObject objectWithId) {
		if (null != objectWithId) {
			handleNewObject(objectWithId);
		}
		TreeIterator<EObject> iterator = objectWithId.eAllContents();
		while (iterator.hasNext()) {
			handleNewObject(iterator.next());
		}
	}

	void handleNewObject(EObject objectWithId) {
		assert null != objectWithId;
		EAttribute idAttribute = objectWithId.eClass().getEIDAttribute();
		if (null != idAttribute) {
			String id = (String) objectWithId.eGet(idAttribute);
			if ((id == null || 0 == id.length()) && createIdForPackages.contains(objectWithId.eClass().getEPackage())) {
				id = EcoreUtil.generateUUID();
				objectWithId.eSet(idAttribute, id);
				// id map gets updated by notification on setId
			} else {
				eObjectToIDMap.put(objectWithId, id);
				idToEObjectMap.put(id, objectWithId);
			}
		}
	}

	void handleRemoveObjectAndSubObjects(EObject objectWithId) {
		if (null != objectWithId) {
			handleRemoveObject(objectWithId);
		}
		TreeIterator<EObject> iterator = objectWithId.eAllContents();
		while (iterator.hasNext()) {
			handleRemoveObject(iterator.next());
		}
	}

	void handleRemoveObject(EObject objectWithId) {
		assert null != objectWithId;
		String id = eObjectToIDMap.remove(objectWithId);
		if (null != id) {
			idToEObjectMap.remove(id);
		}
	}

}