/**
 * 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 javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.events.XMLEvent;
import org.apereo.portal.IUserPreferencesManager;
import org.apereo.portal.layout.IUserLayoutManager;
import org.apereo.portal.user.IUserInstance;
import org.apereo.portal.user.IUserInstanceManager;
import org.apereo.portal.utils.cache.CacheKey;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;

/**
 * Gets the {@link IUserLayoutManager} for the current request and exposes the layout XML via an
 * {@link XMLEventReader}
 *
 */
public class UserLayoutStoreComponent implements StAXPipelineComponent {
    private IUserInstanceManager userInstanceManager;

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    public void setUserInstanceManager(IUserInstanceManager userInstanceManager) {
        this.userInstanceManager = userInstanceManager;
    }

    @Override
    public CacheKey getCacheKey(HttpServletRequest request, HttpServletResponse response) {
        final IUserLayoutManager userLayoutManager = this.getUserLayoutManager(request);
        final String cacheKey = userLayoutManager.getCacheKey();
        return CacheKey.build(this.getClass().getName(), cacheKey);
    }

    @Override
    public PipelineEventReader<XMLEventReader, XMLEvent> getEventReader(
            HttpServletRequest request, HttpServletResponse response) {

        final long timestamp = System.currentTimeMillis();
        logger.debug(
                "STARTING user layout fetch for user '{}' #milestone", request.getRemoteUser());

        final IUserLayoutManager userLayoutManager = getUserLayoutManager(request);

        final XMLEventReader userLayoutReader = userLayoutManager.getUserLayoutReader();

        logger.debug(
                "FINISHED user layout fetch for user '{}' in {}ms #milestone",
                request.getRemoteUser(),
                Long.toString(System.currentTimeMillis() - timestamp));

        return new PipelineEventReaderImpl<XMLEventReader, XMLEvent>(userLayoutReader);
    }

    /** Get the {@link IUserLayoutManager} for the user making the request */
    protected IUserLayoutManager getUserLayoutManager(HttpServletRequest request) {
        final IUserInstance userInstance = this.userInstanceManager.getUserInstance(request);
        final IUserPreferencesManager preferencesManager = userInstance.getPreferencesManager();
        return preferencesManager.getUserLayoutManager();
    }
}