/**
 * This file Copyright (c) 2013 Magnolia International
 * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
 *
 *
 * This file is dual-licensed under both the Magnolia
 * Network Agreement and the GNU General Public License.
 * You may elect to use one or the other of these licenses.
 *
 * This file is distributed in the hope that it will be
 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
 * implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
 * Redistribution, except as permitted by whichever of the GPL
 * or MNA you select, is prohibited.
 *
 * 1. For the GPL license (GPL), you can redistribute and/or
 * modify this file under the terms of the GNU General
 * Public License, Version 3, as published by the Free Software
 * Foundation.  You should have received a copy of the GNU
 * General Public License, Version 3 along with this program;
 * if not, write to the Free Software Foundation, Inc., 51
 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * 2. For the Magnolia Network Agreement (MNA), this file
 * and the accompanying materials are made available under the
 * terms of the MNA which accompanies this distribution, and
 * is available at http://www.magnolia-cms.com/mna.html
 *
 * Any modifications to this file must keep this entire header
 * intact.
 *
 */
package info.magnolia.blossom.sample.module.support;

import javax.servlet.http.HttpServletRequest;

import org.springframework.core.MethodParameter;
import org.springframework.web.bind.support.WebArgumentResolver;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;
import org.springframework.web.servlet.mvc.support.RedirectAttributesModelMap;

/**
 * Web argument resolver that enables using RedirectAttributes in Spring 3.1.x MVC. It mimics the behaviour of
 * {@link org.springframework.web.servlet.mvc.method.annotation.RedirectAttributesMethodArgumentResolver} but rather than
 * changing the model used it collects flash attributes and makes them available as a request attribute where
 * {@link FlashMapEnabledAnnotationMethodHandlerAdapter} can later pick them up.
 *
 * @see FlashMapEnabledAnnotationMethodHandlerAdapter
 * @see org.springframework.web.servlet.mvc.method.annotation.RedirectAttributesMethodArgumentResolver
 */
public class RedirectAttributesWebArgumentResolver implements WebArgumentResolver {

    public static String REDIRECT_ATTRIBUTES_ATTRIBUTE = RedirectAttributesWebArgumentResolver.class.getName();

    @Override
    public Object resolveArgument(MethodParameter parameter, NativeWebRequest webRequest) throws Exception {
        if (!RedirectAttributes.class.isAssignableFrom(parameter.getParameterType())) {
            return UNRESOLVED;
        }

        RedirectAttributes redirectAttributes = new RedirectAttributesModelMap();
        webRequest.getNativeRequest(HttpServletRequest.class).setAttribute(REDIRECT_ATTRIBUTES_ATTRIBUTE, redirectAttributes);
        return redirectAttributes;
    }
}