/**********************************************
    * Copyright (C) 2011 Lukas Laag
    * This file is part of svgreal.
    * 
    * svgreal is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    * 
   * svgreal 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 General Public License for more details.
   * 
   * You should have received a copy of the GNU General Public License
   * along with svgreal.  If not, see http://www.gnu.org/licenses/
   **********************************************/
  package org.vectomatic.svg.edit.client.command;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import org.vectomatic.svg.edit.client.engine.SVGModel;
  import org.vectomatic.svg.edit.client.model.ModelConstants;
  import org.vectomatic.svg.edit.client.model.svg.SVGElementModel;
  import org.vectomatic.svg.edit.client.model.svg.SVGNamedElementModel;
  
  import com.extjs.gxt.ui.client.data.BeanModel;
  import com.extjs.gxt.ui.client.data.BeanModelLookup;
  import com.extjs.gxt.ui.client.util.Format;
  
  /**
   * Class to represent the removal of one or many elements from
   * the SVG model.
   * @author laaglu
   */
  public class GenericRemoveCommand extends CommandBase {
  	/**
  	 * The models to remove
  	 */
  	protected List<SVGElementModel> models;
  	/**
  	 * The parent models of the models to remove
  	 */
  	protected List<SVGElementModel> parentModels;
  	/**
  	 * The next non-null siblings of the models to remove, or null if no such siblings exist
  	 */
  	protected List<SVGElementModel> refModels;
  	/**
  	 * The owner of the models to remove
  	 */
  	protected SVGModel owner;
  	/**
  	 * The command description
  	 */
  	protected String description;
  
  	public GenericRemoveCommand(ICommandFactory factory, List<SVGElementModel> models, String description) {
  		super(factory);
  		// Sort nodes according to their order in the tree.
  		Collections.<SVGElementModel>sort(models, SVGElementModel.getAscendingCompataror());
  		Set<SVGElementModel> modelSet = new HashSet<SVGElementModel>(models);
  		this.models = models;
  		this.description = description;
  		parentModels = new ArrayList<SVGElementModel>();
  		refModels = new ArrayList<SVGElementModel>();
  		for (SVGElementModel model : models) {
  			SVGModel owner = model.getOwner();
  			if (this.owner == null) {
  				this.owner = owner;
  			} else {
  				assert this.owner == owner : "Attempt to remove models from heterogeneous owners: " + this.owner + ", " + owner;
  			}
  			SVGElementModel parentModel = (SVGElementModel) model.getParent();
  			parentModels.add(parentModel);
  			// Retrieve the next sibling not in the set of models to delete
  			SVGElementModel siblingModel = model;
  			while (((siblingModel = siblingModel.getNextSibling()) != null) && modelSet.contains(siblingModel)) {
  			}
  			refModels.add(siblingModel);
  		}
  	}
  
  	@Override
  	public String getDescription() {
  		return description;
  	}
  
  	@Override
  	public void commit() {
  		for (int i = models.size() - 1; i >= 0; i--) {
  			SVGElementModel model = models.get(i);
  			owner.remove(model);
  		}
  	}
 
 	@Override
 	public void rollback() {
 		for (int i = 0, size = models.size(); i < size; i++) {
 			SVGElementModel model = models.get(i);
 			SVGElementModel parentModel = parentModels.get(i);
 			SVGElementModel refModel = refModels.get(i);
 			owner.insertBefore(parentModel, model, refModel);
 		}
 	}
 
 	@Override
 	public BeanModel asModel() {
 		return BeanModelLookup.get().getFactory(GenericRemoveCommand.class).createModel(this);
 	}
 
 }