#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright 2006-2007 (C) Pete Savage <petesavage@ubuntu.com>
# Copyright 2007 (C) Siegfried-A. Gevatter <siggi.gevatter@gmail.com>
# License: GPLv2 or later
#
# This script is used to check if a package and all its build
# dependencies are in main or not.

import subprocess
import sys

def process_deps(deps):
	"""Takes a list of (build) dependencies and processes it."""
	
	for package in [ package.split('|')[0] for package in deps ]:
		
		# Cut package name (from something like "name ( >= version)")
		name = package.split(' ')[0]
		
		if not packages.has_key(name) and name != '':
			# Check the (build) dependencies recursively
			find_main(name)


def find_main(pack):
	"""Searches the dependencies and build dependencies of a package recursively
	to determine if they are all in the 'main' component or not."""
	
	global packages
	
	# Retrieve information about the package
	out = subprocess.Popen('apt-cache madison ' + pack, shell=True, stdout=subprocess.PIPE).stdout.read()
	
	if out.find("/main") != -1:
		packages[pack] = True
		return 1
	else:
		if not packages.has_key(pack):
			packages[pack] = False
		
		# Retrive package dependencies
		deps = subprocess.Popen("apt-cache show " + pack + " | grep Depends", shell=True, stdout=subprocess.PIPE).stdout.read().split('\n')[0].replace('Depends: ', '').split(', ')
		
		process_deps(deps)
		
		# Retrieve package build dependencies
		deps1 = subprocess.Popen("apt-cache showsrc " + pack + " | grep Build-Depends", shell=True, stdout=subprocess.PIPE).stdout.readlines()
		deps = []
		
		for builddep in deps1:
			if builddep.startswith('Build-Depends'):
				deps += builddep.strip('\n').replace('Build-Depends: ', '').replace('Build-Depends-Indep: ',  '').split(', ')
		
		process_deps(deps)


if __name__ == '__main__':
	
	# Check if the amount of arguments is correct
	if len(sys.argv) != 2 or sys.argv[1] in ('help', '-h', '--help'):
		print "Usage: %s <package name>" % sys.argv[0]
		sys.exit(1)

	# Global variable to hold the status of all packages
	packages = {}
	
	if subprocess.Popen("apt-cache show " + sys.argv[1] + " 2>/dev/null", shell=True, stdout=subprocess.PIPE).stdout.read() == '':
		print "Package «%s» doesn't exist." % sys.argv[1]
		sys.exit(1)
	
	try:
		find_main(sys.argv[1])
	except KeyboardInterrupt:
		print 'Aborted.'
		sys.exit(1)
	
	# True if everything checked until the point is in main
	all_in_main = True
	
	for package in packages:
		if not packages[package]:
			if all_in_main:
				print "Following packages aren't in main:"
				all_in_main = False
			print '  ', package
	
	if all_in_main:
		print package, "and all its dependencies are in main."