/**
 * 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.session;

import java.util.Enumeration;
import javax.portlet.PortletRequest;
import javax.portlet.PortletResponse;
import javax.portlet.PortletSession;
import org.apache.pluto.container.driver.AdministrativeRequestListener;

/**
 * Provides access to actions involving the PortletSession. Refer to {@link SessionAction} for
 * supported actions.
 *
 */
public class PortletSessionAdministrativeRequestListener implements AdministrativeRequestListener {
    public static final String ACTION = "org.apereo.portal.portlet.session.ACTION";
    public static final String ARGUMENTS = "org.apereo.portal.portlet.session.ARGUMENTS";
    public static final String SCOPE = "org.apereo.portal.portlet.session.SCOPE";

    public enum SessionAction {
        /** Removes all attributes from the session for the specified scope */
        CLEAR(false, 0), //No arguments

        /** Stores an attribute in the session for the specified scope */
        SET_ATTRIBUTE(true, 2); // arg[0]=Attribute Name, arg[1]=Attribute Value

        private final boolean requiresCreation;
        private final int argumentCount;

        private SessionAction(boolean requiresCreation, int argumentCount) {
            this.requiresCreation = requiresCreation;
            this.argumentCount = argumentCount;
        }

        public boolean isRequiresCreation() {
            return this.requiresCreation;
        }

        public int getArgumentCount() {
            return this.argumentCount;
        }
    }

    /**
     * @see
     *     org.apache.pluto.spi.optional.AdministrativeRequestListener#administer(javax.portlet.PortletRequest,
     *     javax.portlet.PortletResponse)
     */
    public void administer(PortletRequest request, PortletResponse response) {
        final SessionAction action = this.getAction(request);
        final Object[] arguments = this.getArguments(request);
        final int scope = this.getScope(request);

        //Check the argument count
        final int argumentCount = arguments != null ? arguments.length : 0;
        if (argumentCount != action.getArgumentCount()) {
            throw new IllegalArgumentException(
                    "SessionAction "
                            + action
                            + " requires "
                            + action.getArgumentCount()
                            + " arguments but "
                            + argumentCount
                            + " arguments were provided.");
        }

        //Get the session according to the action
        final PortletSession portletSession =
                request.getPortletSession(action.isRequiresCreation());

        switch (action) {
            case CLEAR:
                {
                    if (portletSession != null) {
                        for (final Enumeration<String> attributeNames =
                                        (Enumeration<String>)
                                                portletSession.getAttributeNames(scope);
                                attributeNames.hasMoreElements();
                                ) {
                            final String attributeName = attributeNames.nextElement();
                            portletSession.removeAttribute(attributeName, scope);
                        }
                    }
                }
                break;
            case SET_ATTRIBUTE:
                {
                    final String attributeName = (String) arguments[0];
                    final Object value = arguments[1];
                    portletSession.setAttribute(attributeName, value, scope);
                }
                break;
        }
    }

    protected SessionAction getAction(PortletRequest request) {
        return (SessionAction) request.getAttribute(ACTION);
    }

    protected Object[] getArguments(PortletRequest request) {
        return (Object[]) request.getAttribute(ARGUMENTS);
    }

    protected int getScope(PortletRequest request) {
        final Integer scope = (Integer) request.getAttribute(SCOPE);
        if (scope != null) {
            return scope;
        }

        return PortletSession.PORTLET_SCOPE;
    }
}