/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.lenya.cms.site.usecases;

import java.util.ArrayList;
import java.util.List;

import org.apache.lenya.cms.publication.Document;
import org.apache.lenya.cms.publication.Node;
import org.apache.lenya.cms.publication.Publication;
import org.apache.lenya.cms.publication.util.DocumentHelper;
import org.apache.lenya.cms.usecase.DocumentUsecase;
import org.apache.lenya.cms.usecase.UsecaseException;

/**
 * Delete a language version.
 * 
 * @version $Id$
 */
public class DeleteLanguage extends DocumentUsecase {

    /**
     * @see org.apache.lenya.cms.usecase.AbstractUsecase#doCheckPreconditions()
     */
    protected void doCheckPreconditions() throws Exception {
        super.doCheckPreconditions();
        if (hasErrors()) {
            return;
        }

        Document doc = getSourceDocument();
        
        if (!doc.getArea().equals(Publication.AUTHORING_AREA)) {
            addErrorMessage("This usecase can only be invoked in the authoring area!");
        } else if (doc.getLanguages().length == 1) {
            addErrorMessage("The last language version cannot be removed.");
        }
        
        if (doc.existsVersion(Publication.LIVE_AREA, doc.getLanguage())) {
            addErrorMessage("The document can't be deleted if a live version exists.");
        }
    }

    /**
     * @see org.apache.lenya.cms.usecase.AbstractUsecase#getNodesToLock()
     */
    protected Node[] getNodesToLock() throws UsecaseException {
        List nodes = new ArrayList();
        if(getSourceDocument() != null) {
            Node docNode = getSourceDocument();
            Node siteNode = getSourceDocument().area().getSite();
            nodes.add(docNode);
            nodes.add(siteNode);
        }
        return (Node[]) nodes.toArray(new Node[nodes.size()]);
    }

    /**
     * @see org.apache.lenya.cms.usecase.AbstractUsecase#doExecute()
     */
    protected void doExecute() throws Exception {
        super.doExecute();

        Document document = getSourceDocument();
        document.getLink().delete();
        document.delete();

        setTargetDocument(DocumentHelper.getExistingLanguageVersion(document));
    }

}