/*
 * PatientView
 *
 * Copyright (c) Worth Solutions Limited 2004-2013
 *
 * This file is part of PatientView.
 *
 * PatientView 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.
 * PatientView 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 PatientView in a file
 * titled COPYING. If not, see <http://www.gnu.org/licenses/>.
 *
 * @package PatientView
 * @link http://www.patientview.org
 * @author PatientView <info@patientview.org>
 * @copyright Copyright (c) 2004-2013, Worth Solutions Limited
 * @license http://www.gnu.org/licenses/gpl-3.0.html The GNU General Public License V3.0
 */

package org.patientview.radar.web.behaviours;

import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.behavior.AbstractAjaxBehavior;
import org.apache.wicket.request.handler.resource.ResourceStreamRequestHandler;
import org.apache.wicket.request.resource.ContentDisposition;
import org.apache.wicket.util.resource.IResourceStream;

/**
 * @author Sven Meier
 * @author Ernesto Reinaldo Barreiro (reiern70@gmail.com)
 * @author Jordi Deu-Pons (jordi@jordeu.net)
 */
public abstract class AJAXDownload extends AbstractAjaxBehavior {
    private boolean addAntiCache;

    public AJAXDownload() {
        this(true);
    }

    public AJAXDownload(boolean addAntiCache) {
        super();
        this.addAntiCache = addAntiCache;
    }

    /**
     * Call this method to initiate the download.
     */
    public void initiate(AjaxRequestTarget target) {
        String url = getCallbackUrl().toString();

        if (addAntiCache) {
            url = url + (url.contains("?") ? "&" : "?");
            url = url + "antiCache=" + System.currentTimeMillis();
        }

        // the timeout is needed to let Wicket release the channel
        target.appendJavaScript("setTimeout(\"window.location.href='" + url + "'\", 100);");
    }

    public void onRequest() {
        ResourceStreamRequestHandler handler = new ResourceStreamRequestHandler(getResourceStream(), getFileName());
        handler.setContentDisposition(ContentDisposition.ATTACHMENT);
        getComponent().getRequestCycle().scheduleRequestHandlerAfterCurrent(handler);
    }

    /**
     * Override this method for a file name which will let the browser prompt with a save/open dialog.
     */
    protected String getFileName() {
        return null;
    }

    /**
     * Hook method providing the actual resource stream.
     */
    protected abstract IResourceStream getResourceStream();
}