/**
 * 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.layout.profile;

import java.util.Collections;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;
import org.apereo.portal.security.IPerson;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationListener;
import org.springframework.util.Assert;

/**
 */
public class SessionAttributeProfileMapperImpl
        implements IProfileMapper, ApplicationListener<ProfileSelectionEvent> {

    protected final Logger logger = LoggerFactory.getLogger(getClass());

    /**
     * Since uPortal 4.2, instead of externally relying upon this key and hoping that a runtime
     * SessionAttributeProfileMapperImpl is not configured to use a different key, consider instead
     * firing a ProfileSelectionEvent and let this class store its data itself into the session.
     */
    public static final String DEFAULT_SESSION_ATTRIBUTE_NAME = "profileKey";

    private Map<String, String> mappings = Collections.<String, String>emptyMap();
    private String defaultProfileName = null;
    private String attributeName = DEFAULT_SESSION_ATTRIBUTE_NAME;

    /** Session profile key to database profile fname mappings. */
    public void setMappings(Map<String, String> mappings) {
        this.mappings = mappings;
    }

    /** Default profile name to return if no match is found, defaults to <code>null</code>. */
    public void setDefaultProfileName(String defaultProfileName) {
        this.defaultProfileName = defaultProfileName;
    }

    /** @param attributeName */
    public void setAttributeName(String attributeName) {
        this.attributeName = attributeName;
    }

    @Override
    public String getProfileFname(IPerson person, HttpServletRequest request) {
        final HttpSession session = request.getSession(false);
        if (session == null) {
            logger.debug(
                    "Cannot get a session-stored profile fname from a null session, so returning null.");
            return null;
        }

        final String requestedProfileKey = (String) session.getAttribute(attributeName);
        if (requestedProfileKey != null) {
            final String profileName = mappings.get(requestedProfileKey);
            if (profileName != null) {
                logger.debug(
                        "The stored requested profile key {} mapped to profile fname {}.",
                        requestedProfileKey,
                        profileName);
                return profileName;
            } else {
                logger.warn(
                        "The stored requested profile key {} does not map to any profile fname.",
                        requestedProfileKey);
            }
        } else {
            logger.trace(
                    "There is no requested profile key stored at session attribute {}.",
                    attributeName);
        }

        logger.trace("Falling back on default profile name {} .", defaultProfileName);
        return defaultProfileName;
    }

    /*
     * Store the requested profile key into the user Session so that this SessionAttributeProfileMapperImpl
     * can subsequently find it and use it to determine a profile mapping.
     */
    @Override
    public void onApplicationEvent(final ProfileSelectionEvent event) {
        final HttpSession session = event.getRequest().getSession(false);

        Assert.notNull(session, "Cannot store a profile selection into a null session.");

        session.setAttribute(this.attributeName, event.getRequestedProfileKey());

        logger.trace(
                "Stored desired profile key [{}] into session (at attribute [{}]).",
                event.getRequestedProfileKey(),
                attributeName);

        final String fnameTheKeyMapsTo = this.mappings.get(event.getRequestedProfileKey());

        if (null == fnameTheKeyMapsTo) {
            logger.warn(
                    "The desired profile key {} has no mapping so will have no effect.",
                    event.getRequestedProfileKey());
        }
    }

    @Override
    public String toString() {
        return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE)
                .append("attributeName", this.attributeName)
                .append("mappings", this.mappings)
                .append("defaultProfileName", this.defaultProfileName)
                .toString();
    }
}