#!/usr/bin/env python

"""
installation script for configuration
multi-level unified configuration
"""

import os
import sys
import urllib2
import subprocess
try:
    from subprocess import check_call as call
except ImportError:
    from subprocess import call

REPO='http://k0s.org/hg/configuration'
DEST='configuration' # name of the virtualenv
VIRTUALENV='https://raw.github.com/pypa/virtualenv/develop/virtualenv.py'

def which(binary, path=os.environ['PATH']):
    dirs = path.split(os.pathsep)
    for dir in dirs:
        if os.path.isfile(os.path.join(dir, fileName)):
            return os.path.join(dir, fileName)
        if os.path.isfile(os.path.join(dir, fileName + ".exe")):
            return os.path.join(dir, fileName + ".exe")

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

    # create a virtualenv
    virtualenv = which('virtualenv') or which('virtualenv.py')
    if virtualenv:
        call([virtualenv, DEST])
    else:
        process = subproces.Popen([sys.executable, '-', DEST], stdin=subprocess.PIPE)
        process.communicate(stdin=urllib2.urlopen(VIRTUALENV).read())

    # create a src directory
    src = os.path.join(DEST, 'src')
    os.mkdir(src)

    # clone the repository
    call(['hg', 'clone', REPO], cwd=src)

    # find the virtualenv python
    python = None
    for path in (('bin', 'python'), ('Scripts', 'python.exe')):
        _python = os.path.join(DEST, *path)
        if os.path.exists(_python)
            python = _python
            break
    else:
        raise Exception("Python binary not found in %s" % DEST)

    # find the clone
    filename = REPO.rstrip('/')
    filename = filename.split('/')[-1]
    clone = os.path.join(src, filename)
    assert os.path.exists(clone), "Clone directory not found in %s" % src

    # ensure setup.py exists
    assert os.path.exists(os.path.join(clone, 'setup.py')), 'setup.py not found in %s' % clone

    # install the package in develop mode
    call([python 'setup.py', 'develop'], cwd=clone)