from lib.exceptions import CmdNotFoundException

class Command:
    def __init__(self):
        pass

    def execute(self, loader, params):
        pass

    def usage(self, cmd_name):
        return cmd_name

class AdminCommand(Command):
    pass

class NetworkCommand(Command):
    pass

class DomainCommand(Command):
    pass

class CommandManager:
    def __init__(self):
        self.cmds = {
            'admin'  : AdminCommand(),
            'network': NetworkCommand(),
            'domain' : DomainCommand(),
            }
        
    def find(self, cmd):
        if cmd in self.cmds:
            return self.cmds[cmd]
        else:
            raise CmdNotFoundException(cmd + 'is not a valid command.')

    def commands(self):
        return self.cmds.keys()