/*
* Copyright 2007-2010 the original author or authors.
*
* 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.impalaframework.interactive.command;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import org.impalaframework.command.framework.Command;
import org.impalaframework.command.framework.CommandDefinition;
import org.impalaframework.command.framework.CommandState;
import org.springframework.util.Assert;
public class UsageCommand implements Command {
private Map<String, Command> commands;
private Map<String, String> aliases;
private Map<String, List<String>> aliasLookups;
public UsageCommand(Map<String, Command> commands, Map<String, String> aliases) {
Assert.notNull(commands);
this.commands = commands;
if (aliases != null) {
this.aliases = aliases;
//use TreeMap so that aliases can be sorted
aliasLookups = new TreeMap<String, List<String>>();
Collection<String> aliasKeys = this.aliases.keySet();
for (String alias : aliasKeys) {
String command = aliases.get(alias);
List<String> list = aliasLookups.get(command);
if (list == null) {
list = new ArrayList<String>();
aliasLookups.put(command, list);
}
list.add(alias);
}
}
else {
aliases = emptyStringStringMap();
aliasLookups = emptyStringListMap();
}
}
public boolean execute(CommandState commandState) {
Set<String> commandNames = commands.keySet();
for (String commandName : commandNames) {
String description = "";
Command command = commands.get(commandName);
if (command != null) {
CommandDefinition commandDefinition = command.getCommandDefinition();
if (commandDefinition != null) {
description = commandDefinition.getDescription();
}
}
String aliasText = null;
List<String> aliases = aliasLookups.get(commandName);
if (aliases != null) {
StringBuffer buffer = new StringBuffer(" (aliases: ");
for (String alias : aliases) {
buffer.append(alias);
buffer.append(", ");
}
buffer.delete(buffer.length()-2, buffer.length());
buffer.append("): ");
aliasText = buffer.toString();
} else {
aliasText = ": ";
}
System.out.println(commandName + aliasText + description);
}
return true;
}
public CommandDefinition getCommandDefinition() {
return new CommandDefinition("Shows usage of commands");
}
private Map<String, String> emptyStringStringMap() {
return Collections.<String, String> emptyMap();
}
private Map<String, List<String>> emptyStringListMap() {
return Collections.<String, List<String>> emptyMap();
}
}