/**
 * 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.portlet.rendering.worker;

import java.util.List;
import java.util.concurrent.ExecutorService;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apereo.portal.portlet.om.IPortletWindow;
import org.apereo.portal.portlet.rendering.IPortletRenderer;
import org.apereo.portal.portlet.rendering.PortletRenderResult;
import org.apereo.portal.portlet.rendering.RenderPortletOutputHandler;

/**
 * {@link PortletExecutionWorker} capable of rendering the head content for a portlet.
 *
 */
class PortletRenderHeaderExecutionWorker extends PortletExecutionWorker<PortletRenderResult>
        implements IPortletRenderExecutionWorker {

    private String output = null;

    public PortletRenderHeaderExecutionWorker(
            ExecutorService executorService,
            List<IPortletExecutionInterceptor> interceptors,
            IPortletRenderer portletRenderer,
            HttpServletRequest request,
            HttpServletResponse response,
            IPortletWindow portletWindow) {

        super(
                executorService,
                interceptors,
                portletRenderer,
                request,
                response,
                portletWindow,
                portletWindow.getPortletEntity().getPortletDefinition().getRenderTimeout() != null
                        ? portletWindow.getPortletEntity().getPortletDefinition().getRenderTimeout()
                        : portletWindow.getPortletEntity().getPortletDefinition().getTimeout());
    }

    @Override
    public ExecutionType getExecutionType() {
        return ExecutionType.RENDER_HEADER;
    }

    /* (non-Javadoc)
     * @see org.apereo.portal.portlet.rendering.worker.IPortletRenderExecutionWorker#getOutput(long)
     */
    @Override
    public String getOutput(long timeout) throws Exception {
        this.get(timeout);
        return this.output;
    }

    /**
     * Obtain the RENDER_HEADER output. Note that uPortal supports the model of obtaining HTML
     * markup from the portlet, whether from a Spring view or servlet output and inserting it within
     * the HTML HEAD section of the page. uPortal does not support the model where the portlet
     * creates DOM elements to be written to the HEAD section and constructs the HTML output; e.g.
     * the following does NOT work in uPortal:
     *
     * <p>
     *
     * <pre>
     * Element linkElement = response.createElement(HTML.Tag.SCRIPT.toString());
     * linkElement.setAttribute(HTML.Attribute.TYPE.toString(), "text/javascript");
     * linkElement.setAttribute(HTML.Attribute.SRC.toString(), cssUrl);
     * linkElement.setTextContent(" ");
     * response.addProperty(MimeResponse.MARKUP_HEAD_ELEMENT, linkElement);
     * </pre>
     *
     * @see PortletExecutionWorker#callInternal()
     */
    @Override
    protected PortletRenderResult callInternal() throws Exception {
        final String characterEncoding = response.getCharacterEncoding();
        final RenderPortletOutputHandler renderPortletOutputHandler =
                new RenderPortletOutputHandler(characterEncoding);

        final PortletRenderResult result =
                portletRenderer.doRenderHeader(
                        portletWindowId, request, response, renderPortletOutputHandler);

        this.output = renderPortletOutputHandler.getOutput();

        return result;
    }
}