#!/usr/bin/env python

"""
a workflow for installing ubuntu packages:

- get list of current executables (requires: lsex.py)
- fire up:
  - synaptic
  - ubuntu package metadata editor
  - python package metadata editor (?)
- get
"""

import optparse
import os
import sys

here = os.path.dirname(os.path.realpath(__file__))

# @requires('lsex')
import lsex
# TODO:
# - package lsex.py
# - solve the probem where one (python) resource is wanted in one manner
#   (for lsex.py, in `python/` in http://k0s.org/hg/config )
#   but is also needed as a setup.py dependency
#   (in this case, for this script once it is packaged and which, in fact,
#   blocks this admittedly incomplete script from being packaged)
# - or define a workflow whereby this problem does not happen
# - [META] talk about this in a forum for (python) packaging workflow patterns
# - [META] keywords:
#   - META
#   - TODO
#   - IDEA
#   - SEE ALSO
#   the big idea being that you have a state (memory, a graph), a new
#   association occurs (time moves forward), what responses are possible?
#   keywords classify these.
#   - of course, a number of these are possible for any association
#     (transition), including those of the same type
# SEE ALSO: hmtl2flux
def compare_executables(callback, path=None):
    """
    compare executables before and after firing a callback.
    returns 2-tuple of (added_executables, removed_executables)

    - callbacK: a callable taking no arguments
    - path: list or PATH-style string of directories to search.
            if not specified, use system PATH
    """
    before = set(lsex.lsex(path))
    callback()
    after = set(lsex.lsex(path))

    new = after.difference(before)
    removed = before.difference(after)
    return (new, removed)


def main(args=sys.argv[1:]):

    usage = '%prog [options]'
    parser = optparse.OptionParser(usage=usage, description=__doc__)
    options, args = options.parse_args(args)

if __name__ == '__main__':
    main()