/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * 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 the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>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.apereo.portal.io;

import org.apereo.portal.layout.IUserLayoutStore;
import org.danann.cernunnos.AttributePhrase;
import org.danann.cernunnos.Attributes;
import org.danann.cernunnos.EntityConfig;
import org.danann.cernunnos.Formula;
import org.danann.cernunnos.Phrase;
import org.danann.cernunnos.Reagent;
import org.danann.cernunnos.ReagentType;
import org.danann.cernunnos.ReturnValue;
import org.danann.cernunnos.SimpleFormula;
import org.danann.cernunnos.SimpleReagent;
import org.danann.cernunnos.Task;
import org.danann.cernunnos.TaskRequest;
import org.danann.cernunnos.TaskResponse;
import org.dom4j.Element;

/**
 * Cernunnos <code>Task</code> that inspects a finished XML entity document and generates an
 * appropriate file name, including the appropriate extension. <em>Appropriate</em> means, in this
 * case, that 2 logically separate entities will never produce the same file name, and that
 * generated file names will be legal on all supported operating systems.
 *
 */
public class GenerateEntityFileNameTask implements Task {

    public static final Reagent ENTITY_ELEMENT =
            new SimpleReagent(
                    "ENTITY_ELEMENT",
                    "@entity-element",
                    ReagentType.PHRASE,
                    Element.class,
                    "Root element of the finished XML entity document",
                    new AttributePhrase(Attributes.NODE));

    public static final Reagent LAYOUT_STORE =
            new SimpleReagent(
                    "LAYOUT_STORE",
                    "@layout-store",
                    ReagentType.PHRASE,
                    IUserLayoutStore.class,
                    "The portal's running IUserLayoutStore instance",
                    new AttributePhrase("layoutStore"));

    // Instance Members.
    private Phrase entityElement;
    private Phrase layoutStore;

    /* (non-Javadoc)
     * @see org.danann.cernunnos.Bootstrappable#init(org.danann.cernunnos.EntityConfig)
     */
    public void init(EntityConfig config) {

        // Lock & load reagents
        this.entityElement = (Phrase) config.getValue(ENTITY_ELEMENT);
        this.layoutStore = (Phrase) config.getValue(LAYOUT_STORE);
    }

    /* (non-Javadoc)
     * @see org.danann.cernunnos.Bootstrappable#getFormula()
     */
    public Formula getFormula() {
        return new SimpleFormula(
                GenerateEntityFileNameTask.class, new Reagent[] {ENTITY_ELEMENT, LAYOUT_STORE});
    }

    /* (non-Javadoc)
     * @see org.danann.cernunnos.Phrase#evaluate(org.danann.cernunnos.TaskRequest, org.danann.cernunnos.TaskResponse)
     */
    public void perform(TaskRequest req, TaskResponse res) {
        final Element rootElement = (Element) entityElement.evaluate(req, res);
        final IUserLayoutStore rdbmdls = (IUserLayoutStore) layoutStore.evaluate(req, res);
        SupportedFileTypes y = SupportedFileTypes.getApplicableFileType(rootElement, rdbmdls);
        String entityFileName = y.getSafeFileNameWithExtension(rootElement);
        ReturnValue rslt = (ReturnValue) req.getAttribute(Attributes.RETURN_VALUE);
        rslt.setValue(entityFileName);
    }
}