# -*- coding: utf-8 -*-
"""
    scap.env
    ~~~~~~~~~~~
    command execution

"""
import scap.config as config


class Command(object):
    def __init__(self, *args):
        self.cmd = args

    def __call__(self, *args, **kwargs):
        return " ".join(self.args)


class arg(Command):
    def __init__(self, name, cmd):
        self.name = name
        self.cmd = cmd

    def required(self, required=True):
        self._required = required
        return self

    def __call__(self, **values):
        if self.name in values and values[self.name]:
            val = values[self.name]
            return self.cmd.format(val)
        else:
            return ''


class ComposableCommand(Command):
    def __init__(self, *cmds):
        self.cmds = cmds

    def __call__(self, *args, **values):
        result = []
        parts = self.cmds + args
        for cmd in parts:
            rendered = cmd
            if callable(cmd):
                rendered = cmd(**values)
            if rendered:
                if type(rendered) is str:
                    result.append(rendered)
                else:
                    result.extend(rendered)
        return result


class SubCommand(ComposableCommand):
    pass


env = config.Environment()
SSH_USER = arg('user', '-oUser={}')
SUDO_USER = arg('user', '-u {}')
SSH = ComposableCommand(env['ssh_command'], SSH_USER)
SUDO = ComposableCommand('sudo', SUDO_USER, '-n', '--')