/**
 * 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.layout.dlm;

import org.apereo.portal.PortalException;
import org.apereo.portal.security.IPerson;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

/**
 * Layout processing action for changing a channel parameter in a user's layout.
 *
 */
public class LPAChangeParameter implements ILayoutProcessingAction {
    private String nodeId = null;
    private String name = null;
    private IPerson person = null;
    private Element ilfNode = null;
    private String value = null;

    LPAChangeParameter(String nodeId, String name, String value, IPerson p, Element ilfNode) {
        this.nodeId = nodeId;
        this.name = name;
        this.person = p;
        this.ilfNode = ilfNode;
        this.value = value;
    }

    /**
     * Change the parameter for a channel in both the ILF and PLF using the appropriate mechanisms
     * for incorporated nodes versus owned nodes.
     */
    public void perform() throws PortalException {
        // push the change into the PLF
        if (nodeId.startsWith(Constants.FRAGMENT_ID_USER_PREFIX)) {
            // we are dealing with an incorporated node, adding will replace
            // an existing one for the same target node id and name
            ParameterEditManager.addParmEditDirective(nodeId, name, value, person);
        } else {
            // node owned by user so change existing parameter child directly
            Document plf = RDBMDistributedLayoutStore.getPLF(person);
            Element plfNode = plf.getElementById(nodeId);
            changeParameterChild(plfNode, name, value);
        }
        // push the change into the ILF
        changeParameterChild(ilfNode, name, value);
    }

    /**
     * Look in the passed-in element for a parameter child element whose value is to be changed to
     * the passed-in value.
     *
     * @param node the parent node in which to create the parameter.
     * @param name the name of the parameter to be created.
     * @param value the value of the parameter to be created.
     */
    static void changeParameterChild(Element node, String name, String value) {
        if (node != null) {
            boolean foundIt = false;

            for (Element parm = (Element) node.getFirstChild();
                    parm != null;
                    parm = (Element) parm.getNextSibling()) {
                Attr att = parm.getAttributeNode(Constants.ATT_NAME);
                if (att != null && att.getValue().equals(name)) {
                    parm.setAttribute(Constants.ATT_VALUE, value);
                    foundIt = true;
                    break;
                }
            }
            if (!foundIt) // if didn't find it add a new one
            LPAAddParameter.addParameterChild(node, name, value);
        }
    }
}