#!/usr/bin/python

# Copyright 2012 Paul Wise
# Released under the MIT/Expat license, see doc/COPYING

# Creates a configuration file for Planet Debian derivatives based on the config
# snippets of all the derivatives.
#
# Usage:
# aggregate-planet-config <list of derivatives> <planet config>

import os
import sys
from tempfile import NamedTemporaryFile as tempfile

derivatives = sys.argv[1:-1]
config = sys.argv[-1]

try:
	f = open(config)
	old_config = f.read()
	f.close()
except IOError:
	old_config = None

new_config = []

for d in derivatives:
	try:
		f = open(os.path.join(d,'status'))
		status = f.read().strip()
		f.close()
		if status and status != 'active':
			continue
	except IOError:
		pass

	try:
		f = open(os.path.join(d,'planet-config'))
		new_config.append(f.read())
		f.close()
	except IOError:
		pass

new_config = '\n'.join(new_config)

if new_config and new_config != old_config:
	tmp = tempfile(prefix=config+'.tmp.', dir='', delete=False)
	tmp.write(new_config)
	tmp.close()
	dummy = open(tmp.name+'.dummy','w')
	dummy.close()
	os.chmod(tmp.name, os.stat(dummy.name).st_mode)
	os.remove(dummy.name)
	os.rename(tmp.name, config)