/*******************************************************************************
 * Copyright (c) 2011 GigaSpaces Technologies Ltd. All rights reserved
 *
 * Licensed 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 org.cloudifysource.shell.commands;

import java.text.MessageFormat;
import java.util.Collection;
import java.util.Map;

import org.apache.felix.gogo.commands.Argument;
import org.apache.felix.gogo.commands.Command;
import org.apache.felix.gogo.commands.CompleterValues;
import org.cloudifysource.shell.Constants;

/**
 * @author uri, adaml, barakm
 * @since 2.0.0
 *
 *        Lists all instances of a certain service.
 *
 *        Required arguments:
 *         service-name - The service name
 *
 *        Command syntax: list-instances service-name
 */

@Command(scope = "cloudify", name = "list-instances", description = "Lists all instances of a certain service")
public class ListInstances extends AdminAwareCommand {

	@Argument(index = 0, name = "service-name", required = true, description = "The service name")
	private String serviceName;

	/**
	 * Gets a list of all services deployed on the current application.
	 *
	 * @return Collection of all services deployed on the current application
	 * @throws Exception
	 *             Reporting a failure to retrieve the current application name or its services
	 */
	@CompleterValues(index = 0)
	public Collection<String> getCompleterValues() throws Exception {
		return adminFacade.getServicesList(getCurrentApplicationName());
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected Object doExecute() throws Exception {
		final Map<String, Object> instanceIdToHostMap = adminFacade.getInstanceList(
				(String) session.get(Constants.ACTIVE_APP), serviceName);
		if (instanceIdToHostMap.isEmpty()) {
			return MessageFormat.format(messages.getString("no_instances_found"), serviceName);
		}
		final StringBuilder builder = new StringBuilder("Instance\t\tHost/Public Ip\n");
		for (final Map.Entry<String, Object> entry : instanceIdToHostMap.entrySet()) {
			builder.append("instance #").append(entry.getKey()).append("\t\t").append(entry.getValue()).append('\n');
		}
		return builder.toString();
	}

}