/*
 * Copyright 2015 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * 
 *      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.eclipse.webdav.dom;

import org.eclipse.webdav.Policy;
import org.w3c.dom.Element;

/**
 * An element editor for the WebDAV propstat element. See RFC2518
 * section 12.9.1.1 for the element's definition.
 * <p>
 * <b>Note:</b> This class/interface is part of an interim API that is still under 
 * development and expected to change significantly before reaching stability. 
 * It is being made available at this early stage to solicit feedback from pioneering 
 * adopters on the understanding that any code that uses this API will almost 
 * certainly be broken (repeatedly) as the API evolves.
 * </p>
 *
 * @see org.eclipse.webdav.http.client.Response
 * @see Prop
 */
public class PropStat extends ElementEditor {
    /**
     * An ordered collection of the element names of the propstat
     * element's children.
     */
    protected static final String[] childNames = new String[] {"prop", "status", "responsedescription"}; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$

    /**
     * Creates a new editor on the given WebDAV propstat element. The
     * element is assumed to be well formed.
     *
     * @param root a propstat element
     * @throws        MalformedElementException if there is reason to
     *                believe that the element is not well formed
     */
    public PropStat(Element root) throws MalformedElementException {
        super(root, "propstat"); //$NON-NLS-1$
    }

    /**
     * Returns this propstat's prop.
     *
     * @return this propstat's prop
     * @throws MalformedElementException if there is reason to believe that
     *         this editor's underlying element is not well formed
     */
    public Prop getProp() throws MalformedElementException {
        Element prop = getFirstChild(root, "prop"); //$NON-NLS-1$
        ensureNotNull(Policy.bind("ensure.missingPropElmt"), prop); //$NON-NLS-1$
        return new Prop(prop);
    }

    /**
     * Returns this propstat's response description.
     *
     * @return this propstat's response description
     * @throws MalformedElementException if there is reason to believe that
     *         this editor's underlying element is not well formed
     */
    public String getResponseDescription() throws MalformedElementException {
        return getChildText(root, "responsedescription", false); //$NON-NLS-1$
    }

    /**
     * Returns this propstat's status.
     *
     * @return this propstat's status
     * @throws MalformedElementException if there is reason to believe that
     *         this editor's underlying element is not well formed
     */
    public String getStatus() throws MalformedElementException {
        String status = getChildText(root, "status", false); //$NON-NLS-1$
        ensureNotNull(Policy.bind("ensure.missingStatusElmt"), status); //$NON-NLS-1$
        return status;
    }

    /**
     * Returns this propstat's status code.
     *
     * @return this propstat's status code
     * @throws MalformedElementException if there is reason to believe that
     *         this editor's underlying element is not well formed
     */
    public int getStatusCode() throws MalformedElementException {
        return new Status(getStatus()).getStatusCode();
    }

    /**
     * Creates and sets a new prop on this propstat and returns an editor on
     * it.
     *
     * @return an editor on a new prop element
     */
    public Prop setProp() {
        Element prop = setChild(root, "prop", childNames, true); //$NON-NLS-1$
        try {
            return new Prop(prop);
        } catch (MalformedElementException e) {
            Assert.isTrue(false, Policy.bind("assert.internalError")); //$NON-NLS-1$
            return null; // Never reached.
        }
    }

    /**
     * Sets this propstat's response description to the given value. If the
     * value is <code>null</code> and a response description has already
     * been set, it is removed.
     *
     * @param value a response description, or <code>null</code>
     */
    public void setResponseDescription(String value) {
        if (value == null) {
            Element child = getLastChild(root, "responsedescription"); //$NON-NLS-1$
            if (child != null)
                root.removeChild(child);
        } else
            setChild(root, "responsedescription", value, childNames, false); //$NON-NLS-1$
    }

    /**
     * Sets the status on this propstat to the given status. The status
     * must not be <code>null</code>.
     *
     * @param status the status for this propstat
     */
    public void setStatus(String status) {
        Assert.isNotNull(status);
        setChild(root, "status", status, childNames, true); //$NON-NLS-1$
    }
}
