/**
 * Copyright (c) 2009 - 2012 Red Hat, Inc.
 *
 * This software is licensed to you under the GNU General Public License,
 * version 2 (GPLv2). There is NO WARRANTY for this software, express or
 * implied, including the implied warranties of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. You should have received a copy of GPLv2
 * along with this software; if not, see
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * Red Hat trademarks are not licensed under GPLv2. No permission is
 * granted to use or replicate Red Hat trademarks that are incorporated
 * in this software or its documentation.
 */
package org.candlepin.common.resteasy.filter;

import org.candlepin.common.jackson.DynamicFilterData;

import org.jboss.resteasy.spi.ResteasyProviderFactory;

import java.util.List;
import java.util.Map;

import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerRequestFilter;
import javax.ws.rs.container.PreMatching;
import javax.ws.rs.ext.Provider;

/**
 * DynamicJsonFilter
 *
 * A class to intercept api calls, and filter the json response based
 * on "include" and "exclude" parameter arrays.
 *
 * If an attribute name is mistyped, we want to continue gracefully
 * with no messages.  It is important in order to preserve compatibility.
 *
 * This supports subtypes, ex: ?exclude=owner.href
 */
@Provider
@PreMatching
public class DynamicJsonFilter implements ContainerRequestFilter {

    @Override
    public void filter(ContainerRequestContext requestContext) {
        Map<String, List<String>> queryParams = requestContext.getUriInfo().getQueryParameters();
        boolean containsExcludes = queryParams.containsKey("exclude");
        boolean containsIncludes = queryParams.containsKey("include");

        DynamicFilterData filterData = new DynamicFilterData();

        if (queryParams.containsKey("filtermode")) {
            List<String> values = queryParams.get("filtermode");
            filterData.setWhitelistMode("whitelist".equalsIgnoreCase(values.get(0)));
        }
        else {
            // We want the list to be a blacklist by default when neither include nor exclude is
            // provided, so we don't accidentally filter anything
            filterData.setWhitelistMode(containsIncludes && !containsExcludes);
        }

        if (containsIncludes) {
            for (String path : queryParams.get("include")) {
                filterData.includeAttribute(path);
            }
        }

        if (containsExcludes) {
            for (String path : queryParams.get("exclude")) {
                filterData.excludeAttribute(path);
            }
        }

        if (containsIncludes || containsExcludes) {
            ResteasyProviderFactory.pushContext(DynamicFilterData.class, filterData);
        }
    }
}