#!/usr/bin/env python
#
#   bigpkg : find packages that require a lot of space on your system
#   v0.2.1 (2009-06-01)
#
#   Copyright (c) 2009 by Allan McRae <allan@archlinux.org>
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

import os, re

LOCAL_DB_PATH="/var/lib/pacman/local"

def strip_versioning(pkg):
	r = re.compile('[^=,^<,^>]+')
	m = r.match(pkg)
	return m.group()

def parse_package_info(pkg, dir):
	# depends and provides
	pkg_deps[pkg] = []
	pkg_provides[pkg] = []

	file = LOCAL_DB_PATH + "/" + dir + "/depends"
	f = open(file)

	while 1:
		line = f.readline();
		if len(line) == 0:
			break
		if line[0:9] == "%DEPENDS%":
			while 1:
				line = f.readline();
				if len(line) == 1:
					break
				pkg_deps[pkg].append(strip_versioning(line.strip()))
		if line[0:10] == "%PROVIDES%":
			while 1:
				line = f.readline();
				if len(line) == 1:
					break
				pkg_provides[pkg].append(strip_versioning(line.strip()))
	f.close()

	# size
	pkg_size[pkg] = 0

	file = LOCAL_DB_PATH + "/" + dir + "/desc"
	f = open(file)
	while 1:
		line = f.readline()
		if len(line) == 0:
			break
		if line[0:6] == "%SIZE%":
			line = f.readline();
			pkg_size[pkg] = int(line)/1024
			break
	f.close()


pkg_list = []
pkg_deps = {}
pkg_provides = {}
pkg_size = {}

for dir in os.listdir(LOCAL_DB_PATH):
	pkg = dir[0:dir.rfind("-",0,dir.rfind("-"))]
	pkg_list.append(pkg)
	parse_package_info(pkg, dir)

pkg_deptree = {}

for pkg in pkg_list:
	pkg_deptree[pkg] = pkg_deps[pkg]
	for dep in pkg_deptree[pkg]:
			if dep in pkg_deps:
				for rdep in pkg_deps[dep]:
					if not rdep in pkg_deptree[pkg]:
						pkg_deptree[pkg].append(rdep);
			else:
				for key in pkg_provides:
					if dep in pkg_provides[key]:
						pkg_deptree[pkg][pkg_deptree[pkg].index(dep)] = key
						dep = key
						break
				for rdep in pkg_deps[dep]:
					if not rdep in pkg_deptree[pkg]:
						pkg_deptree[pkg].append(rdep);				

needed_by = {}
for pkg in pkg_list:
	needed_by[pkg] = 0

for pkg in pkg_list:
	for dep in pkg_deptree[pkg]:
		needed_by[dep] += 1

pkg_usage = {}
for pkg in pkg_list:
	if needed_by[pkg] == 0:
		pkg_usage[pkg] = pkg_size[pkg]
		for dep in pkg_deps[pkg]:
			pkg_usage[pkg] += pkg_size[dep] / needed_by[dep]

pkg_usage = [ [v[1],v[0]] for v in pkg_usage.items()]
pkg_usage.sort()

for pkg in range(len(pkg_usage)):
	print ("%s: %dK" % (pkg_usage[pkg][1], round(pkg_usage[pkg][0])))