/**
 * 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 java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Required;
import org.springframework.util.Assert;

/**
 * PortalRenderingPipeline that issues a redirect to a configured path. Intended as a Pipeline
 * implementation that might be plugged into a branch in the overall rendering pipeline and
 * conditionally actuated.
 *
 * @since 4.2
 */
public class RedirectRenderingPipelineTerminator implements IPortalRenderingPipeline {

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

    /** Path to which terminator will redirect. */
    private String redirectTo;

    @Override
    public void renderState(final HttpServletRequest request, final HttpServletResponse response)
            throws ServletException, IOException {

        if (null == this.redirectTo) {
            throw new IllegalStateException(
                    "RedirectRenderingPipelineTerminator must be configured "
                            + "with path to which to redirect.");
        }

        logger.trace("Redirecting to {} .", this.redirectTo);

        response.sendRedirect(this.redirectTo);
    }

    /**
     * Set the path to which the pipeline terminator should redirect. Required.
     *
     * @param targetPath non-null path String suitable for presentation to response.sendRedirect().
     * @throws IllegalArgumentException if targetPath is null.
     */
    @Required
    public void setRedirectTo(final String targetPath) {

        Assert.notNull(targetPath);

        this.redirectTo = targetPath;
    }
}