/**
 * 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.utils.web;

import java.util.Collections;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import org.springframework.web.context.request.async.WebAsyncUtils;

/**
 * Scopes set request attributes to just this request.
 *
 */
public class PortletHttpServletRequestWrapper extends AbstractHttpServletRequestWrapper {
    /**
     * {@link javax.servlet.http.HttpServletRequest} attribute that this {@link HttpServletRequest}
     * object will be available.
     */
    public static final String ATTRIBUTE__HTTP_SERVLET_REQUEST =
            PortletHttpServletRequestWrapper.class.getName() + ".PORTLET_HTTP_SERVLET_REQUEST";

    private final Map<String, Object> attributes = new LinkedHashMap<String, Object>();

    public PortletHttpServletRequestWrapper(HttpServletRequest httpServletRequest) {
        super(httpServletRequest);
    }

    @Override
    public Object getAttribute(String name) {
        if (ATTRIBUTE__HTTP_SERVLET_REQUEST.equals(name)) {
            return this;
        }

        final Object attribute = this.attributes.get(name);
        if (attribute != null) {
            return attribute;
        }

        if (WebAsyncUtils.WEB_ASYNC_MANAGER_ATTRIBUTE.equals(name)) {
            /*
             * Spring WebAsyncManager has an issue with cross-context request
             * dispatching;  it has the potential to break the portlet
             * container.  See the following page:
             *
             *   - http://stackoverflow.com/questions/22128150/spring-and-cross-context-webasyncmanager-cannot-be-cast-to-webasyncmanager
             */
            return null;
        }

        return super.getAttribute(name);
    }

    @Override
    public Enumeration<String> getAttributeNames() {
        final Set<String> attributeNames = this.attributes.keySet();
        return Collections.enumeration(attributeNames);
    }

    @Override
    public void removeAttribute(String name) {
        this.attributes.remove(name);
    }

    @Override
    public void setAttribute(String name, Object o) {
        this.attributes.put(name, o);
    }
}