/*
 * Copyright 2012, 2013 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.common.cli;

import java.util.ArrayList;
import java.util.Collection;

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

import com.redhat.thermostat.common.utils.ServiceRegistry;

/**
 * This class mainly wraps around a ServiceRegistry object, handling the additional
 * non-osgi-specific task of enable/disable of Command objects as they are registered
 * or unregistered.
 */
public class CommandRegistryImpl implements CommandRegistry {

    private BundleContext context;
    private ServiceRegistry<Command> proxy;
    private Collection<Command> myRegisteredCommands;

    public CommandRegistryImpl(BundleContext ctx) {
        context = ctx;
        proxy = new ServiceRegistry<Command>(ctx, Command.class.getName());
        myRegisteredCommands = new ArrayList<>();
    }

    @Override
    public void registerCommand(Command cmd) {
        proxy.registerService(cmd, cmd.getName());
        myRegisteredCommands.add(cmd);
    }

    @Override
    public void registerCommands(Iterable<? extends Command> cmds) {
        for (Command cmd : cmds) {
            registerCommand(cmd);
        }
    }

    @Override
    public void unregisterCommands() {
        proxy.unregisterAll();
    }

    @Override
    public Command getCommand(String name) {
        Command command = proxy.getService(name);
        if (command instanceof CommandWithInfo) {
            initializeCommandInfo((CommandWithInfo) command);
        }
        return command;
    }

    void initializeCommandInfo(CommandWithInfo command) {
        if (!command.hasCommandInfo()) {
            @SuppressWarnings("rawtypes")
            ServiceReference infosRef = context.getServiceReference(CommandInfoSource.class);
            @SuppressWarnings("unchecked")
            CommandInfoSource infos = (CommandInfoSource) context.getService(infosRef);
            command.setCommandInfo(infos.getCommandInfo(command.getName()));
            context.ungetService(infosRef);
        }
    }

    @Override
    public Collection<Command> getRegisteredCommands() {
        return proxy.getRegisteredServices();
    }

}