/*
 * Copyright 2012-2014 Red Hat, Inc.
 *
 * This file is part of Thermostat.
 *
 * Thermostat is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2, or (at your
 * option) any later version.
 *
 * Thermostat is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Thermostat; see the file COPYING.  If not see
 * <http://www.gnu.org/licenses/>.
 *
 * Linking this code with other modules is making a combined work
 * based on this code.  Thus, the terms and conditions of the GNU
 * General Public License cover the whole combination.
 *
 * As a special exception, the copyright holders of this code give
 * you permission to link this code with independent modules to
 * produce an executable, regardless of the license terms of these
 * independent modules, and to copy and distribute the resulting
 * executable under terms of your choice, provided that you also
 * meet, for each linked independent module, the terms and conditions
 * of the license of that module.  An independent module is a module
 * which is not derived from or based on this code.  If you modify
 * this code, you may extend this exception to your version of the
 * library, but you are not obligated to do so.  If you do not wish
 * to do so, delete this exception statement from your version.
 */

package com.redhat.thermostat.launcher.internal;

import java.util.Arrays;
import java.util.logging.Logger;

import org.osgi.framework.BundleContext;
import org.osgi.framework.Constants;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;

import com.redhat.thermostat.common.cli.Command;
import com.redhat.thermostat.common.cli.CommandRegistryImpl;
import com.redhat.thermostat.common.utils.LoggingUtils;

/**
 * Provides {@link Command} and {@link CommandInfo} objects for a given command
 * name.
 *
 * @see CommandRegistryImpl
 */
public class CommandSource {

    private static final Logger logger = LoggingUtils.getLogger(CommandSource.class);

    private final BundleContext context;

    public CommandSource(BundleContext context) {
        this.context = context;
    }

    public Command getCommand(String name) {
        try {
            ServiceReference[] refs = context.getAllServiceReferences(Command.class.getName(), "(" + Command.NAME + "=" + name + ")");
            if (refs == null) {
                return null;
            } else if (refs.length > 1) {
                logger.warning("More than one matching command implementation found for " + name);
                for (int i = 0; i < refs.length; i++) {
                    logger.warning(name + " is provided by + " + Arrays.toString((String[])refs[i].getProperty(Constants.OBJECTCLASS)));
                }
            }
            ServiceReference ref = refs[0];
            return (Command) context.getService(ref);
        } catch (InvalidSyntaxException e) {
            throw new IllegalArgumentException("bad name for command: " + name, e);
        }
    }

}
