/**
 * 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.rendering;

import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLEventFactory;
import javax.xml.stream.events.Attribute;
import javax.xml.stream.events.StartElement;
import org.apereo.portal.layout.IUserLayoutManager;
import org.apereo.portal.portlet.dao.IPortletDefinitionDao;
import org.apereo.portal.portlet.om.IPortletDefinition;
import org.apereo.portal.portlet.om.IPortletDescriptorKey;
import org.apereo.portal.portlet.om.IPortletWindow;
import org.apereo.portal.portlet.om.IPortletWindowId;
import org.apereo.portal.portlet.registry.IPortletWindowRegistry;
import org.apereo.portal.utils.cache.CacheKey;
import org.apereo.portal.utils.cache.CacheKey.CacheKeyBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.annotation.Autowired;

/**
 * Base implementation of portlet definition source that adds the portlet webapp, name, and
 * framework portlet info
 *
 */
public class PortletDefinitionAttributeSource implements AttributeSource, BeanNameAware {
    protected final Logger logger = LoggerFactory.getLogger(getClass());

    public static final QName PORTLET_FNAME_ATTR_NAME = new QName("fname");
    public static final String WEBAPP_NAME_ATTRIBUTE = "webAppName";
    public static final String PORTLET_NAME_ATTRIBUTE = "portletName";
    public static final String FRAMEWORK_PORTLET_ATTRIBUTE = "frameworkPortlet";
    public static final String PORTLET_LIFECYCLE_ATTRIBUTE = "lifecycleState";

    private final XMLEventFactory xmlEventFactory = XMLEventFactory.newFactory();
    private IPortletDefinitionDao portletDefinitionDao;
    private IPortletWindowRegistry portletWindowRegistry;
    private String name;

    @Autowired
    public void setPortletDefinitionDao(IPortletDefinitionDao portletDefinitionDao) {
        this.portletDefinitionDao = portletDefinitionDao;
    }

    @Autowired
    public void setPortletWindowRegistry(IPortletWindowRegistry portletWindowRegistry) {
        this.portletWindowRegistry = portletWindowRegistry;
    }

    @Override
    public void setBeanName(String name) {
        this.name = name;
    }

    @Override
    public final Iterator<Attribute> getAdditionalAttributes(
            HttpServletRequest request, HttpServletResponse response, StartElement event) {

        final QName eventName = event.getName();
        final String localEventName = eventName.getLocalPart();

        //Only pay attention to channel events
        if (!IUserLayoutManager.CHANNEL.equals(localEventName)) {
            return null;
        }

        final Collection<Attribute> attributes = new LinkedList<Attribute>();

        // Add the portlet's portlet name and either the webapp URL or framework flag to the list of attributes.
        final Attribute fnameAttribute = event.getAttributeByName(PORTLET_FNAME_ATTR_NAME);
        if (fnameAttribute != null) {
            final String fname = fnameAttribute.getValue();
            IPortletDefinition def = portletDefinitionDao.getPortletDefinitionByFname(fname);
            if (def == null) {
                this.logger.warn(
                        "Cannot get portlet definition attributes.  No portlet definition found for fname: '"
                                + fname
                                + "'.");
            } else {
                IPortletDescriptorKey descriptorKey = def.getPortletDescriptorKey();
                attributes.add(
                        xmlEventFactory.createAttribute(
                                PORTLET_NAME_ATTRIBUTE, descriptorKey.getPortletName()));
                attributes.add(
                        xmlEventFactory.createAttribute(
                                PORTLET_LIFECYCLE_ATTRIBUTE, def.getLifecycleState().toString()));
                if (descriptorKey.isFrameworkPortlet()) {
                    attributes.add(
                            xmlEventFactory.createAttribute(FRAMEWORK_PORTLET_ATTRIBUTE, "true"));
                } else {
                    attributes.add(
                            xmlEventFactory.createAttribute(
                                    WEBAPP_NAME_ATTRIBUTE, descriptorKey.getWebAppName()));
                }
            }
        }

        return attributes.iterator();
    }

    @Override
    public final CacheKey getCacheKey(HttpServletRequest request, HttpServletResponse response) {
        final CacheKeyBuilder cacheKeyBuilder = CacheKey.builder(this.name);

        // We need something that makes for a unique cache key.  For lack of anything else useful,
        // use the set of all layout portlet window ids in the user's layout.
        final Set<IPortletWindow> portletWindows =
                this.portletWindowRegistry.getAllLayoutPortletWindows(request);

        for (final IPortletWindow portletWindow : portletWindows) {
            if (portletWindow != null) {
                final IPortletWindowId portletWindowId = portletWindow.getPortletWindowId();
                cacheKeyBuilder.add(portletWindowId);
            } else {
                this.logger.warn(
                        "portletWindowRegistry#getAllLayoutPortletWindows() returned a null portletWindow");
            }
        }

        return cacheKeyBuilder.build();
    }
}