/**
 *  Copyright 2005-2015 Red Hat, Inc.
 *
 *  Red Hat 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
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  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 io.fabric8.mq.fabric.discovery;

import java.io.IOException;
import java.net.URI;
import java.util.Map;

import org.apache.activemq.transport.discovery.DiscoveryAgent;
import org.apache.activemq.transport.discovery.DiscoveryAgentFactory;
import org.apache.activemq.util.IOExceptionSupport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static org.apache.activemq.util.URISupport.parseQuery;
import static org.apache.activemq.util.URISupport.stripPrefix;

public class FabricDiscoveryAgentFactory extends DiscoveryAgentFactory {

    private static final Logger LOG = LoggerFactory.getLogger(FabricDiscoveryAgentFactory.class);

    protected DiscoveryAgent doCreateDiscoveryAgent(URI uri) throws IOException {
        try {
            FabricDiscoveryAgent rc;
            boolean osgi = false;

            // detect osgi
            try {
                if (OsgiUtil.isOsgi()) {
                    LOG.info("OSGi environment detected!");
                    osgi = true;
                }
            } catch (Throwable ignore) {
                LOG.debug("OSGi not detected due " + ignore.getMessage() + ". This exception is ignored.", ignore);
            }

            if (osgi) {
                rc = OsgiUtil.createOsgiDiscoveryAgent();
            } else {
                rc = new FabricDiscoveryAgent();
            }

            if (uri.getSchemeSpecificPart() != null && uri.getSchemeSpecificPart().length() > 0) {
                String ssp = stripPrefix(uri.getSchemeSpecificPart(), "//");
                Map<String, String> query = parseQuery(ssp);
                String groupName = ssp.split("\\?")[0];
                if (query.get("id") != null) {
                    rc.setId(query.get("id"));
                }
                rc.setGroupName(groupName);
            }
            return rc;

        } catch (Throwable e) {
            throw IOExceptionSupport.create("Could not create discovery agent: " + uri, e);
        }
    }

    static class OsgiUtil {
        static boolean isOsgi() {
            return (org.osgi.framework.FrameworkUtil.getBundle(FabricDiscoveryAgentFactory.class) != null);
        }

        static FabricDiscoveryAgent createOsgiDiscoveryAgent() {
            return new OsgiFabricDiscoveryAgent();
        }
    }
}
