groovy-core/src/main/org/codehaus/groovy/tools/shell/commands/AliasCommand.groovy

/*
 * Copyright 2003-2007 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.codehaus.groovy.tools.shell.commands

import org.codehaus.groovy.tools.shell.CommandSupport
import org.codehaus.groovy.tools.shell.Shell

/**
 * The 'alias' command.
 *
 * @version $Id$
 * @author <a href="mailto:jason@planet57.com">Jason Dillon</a>
 */
class AliasCommand
    extends CommandSupport
{
    AliasCommand(final Shell shell) {
        super(shell, 'alias', '\\a')
    }

    Object execute(final List args) {
        assert args != null
        
        if (args.size() < 2) {
            fail("Command 'alias' requires at least 2 arguments") // TODO: i18n
        }
        
        String name = args[0]
        List target = args[1..-1]
        
        def command = registry[name]
        
        if (command) {
            if (command instanceof AliasTargetProxyCommand) {
                log.debug("Rebinding alias: $name")
                
                registry.remove(command)
            }
            else {
                fail("Can not rebind non-user aliased command: ${command.name}") // TODO: i18n
            }
        }
        
        log.debug("Creating alias '$name' to: $target")
        
        // Register the command
        command = shell << new AliasTargetProxyCommand(shell, name, target)
        
        //
        // TODO: Should this be here... or should this be in the Shell's impl?
        //
        
        // Try to install the completor
        if (shell.runner) {
            shell.runner.completor << command
        }
    }
}

class AliasTargetProxyCommand
    extends CommandSupport
{
    private static int counter = 0
    
    final List args
    
    AliasTargetProxyCommand(final Shell shell, final String name, final List args) {
        super(shell, name, '\\a' + counter++)
        
        assert args
        
        this.args = args
    }
    
    String getDescription() {
        return "User defined alias to: @|bold ${args.join(' ')}|"
    }

    String getUsage() {
        return ''
    }
    
    String getHelp() {
        return description
    }
    
    Object execute(List args) {
        args = this.args + args
        
        log.debug("Executing with args: $args")
        
        //
        // FIXME: Should go back through shell.execute() to allow aliases to groovy snips too
        //
        
        return shell.executeCommand(args.join(' '))
    }
}