command.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import sys
import os
import click
from pathlib import Path

CONTEXT_SETTINGS = {
    'ignore_unknown_options': True,
    'allow_extra_args': True,
}


class SymlinkGroup(click.Group):
    def get_command(self, ctx, cmd_name):
        rv = click.Group.get_command(self, ctx, cmd_name)
        if rv is not None:
            click.echo(click.style('invoke: %s' % cmd_name, fg='green'))
            return rv

        sym_name = get_sym_name()
        if sym_name is None:
            return None

        rv = click.Group.get_command(self, ctx, sym_name)
        if rv is not None:
            argv = list(sys.argv)
            argv.insert(argv.index(cmd_name), sym_name)
            click.echo(click.style('exec: %s' % argv, fg='green'))
            os.execl(argv[0], *argv)
            raise RuntimeError('failed to execl')
        else:
            return None


@click.command(
    cls=SymlinkGroup,
    context_settings=CONTEXT_SETTINGS,
    invoke_without_command=True,
)
@click.option('-d', '--debug',
              type=int,
              count=True,
              default=0,
              envvar='FOO_DEBUG',
              help='enable/disable debug mode')
@click.pass_context
def main(ctx, **kwargs):
    ctx.obj = {}
    ctx.obj['DEBUG'] = kwargs['debug']

    click.echo('Debug mode is %s' % ('on' if ctx.obj['DEBUG'] else 'off'))
    click.echo('================')


@main.command()
@click.option('--force',
              is_flag=True,
              default=False,
              )
@click.option('--yes',
              is_flag=True,
              default=False,
              )
@click.pass_context
def foo(ctx, **kwargs):
    click.echo('>> foo')
    click.echo('  force: %s' % kwargs['force'])
    click.echo('  yes  : %s' % kwargs['yes'])


# foo-bar-baz => bar_baz
def get_sym_name():
    prog_name = Path(__file__).stem
    e = prog_name.split('-')[1:]
    if e:
        return '_'.join(e)
    else:
        return None


if __name__ == '__main__':
    main()