#!/usr/bin/python
#
#    checkupdates.py -- Compares Red Hat tree to updates directory and lists 
#       availible updates.
#    Copyright (C) 2002 Jack Neely
#
#    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, write to the Free Software
#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#

import os
import os.path
import rpm
import sys
import getopt

verbose = 0

def usage():
	print "Usage:" + sys.argv[0] + "-v ver -r arch [listofrpms]"
	print " Required arguments:"
	print "    -v, --ver [version of distro]"
	print "    -r, --arch [architecture of distro]"
	print "    -e, --tree [where the top of the tree is]"
	print "    -u, --updates [path to update directory]"
	print
	print " Optional arguments:"
	print "    -V, --verbose\tVerbose mode"
	print "    -h, --help\t\tPrint this message"
	print
	sys.exit(1)
	
def log(mess):
	global verbose
	if verbose:
		print mess

def getHeader(filename):
	fd = os.open(filename, os.O_RDONLY)
	header, isSource = rpm.headerFromPackage(fd)
	os.close(fd)
	return (header, isSource)

# sanity checks on the list list.  Can preppend root to aid in
# absolute path resolving.
# Make damn sure this looks like an RPM....

def checkFiles(filelist, rt=""):
	files = []
	for file in filelist:
		path = os.path.abspath(os.path.join(rt,file))
		log(path)
		if not os.access(path, os.R_OK):
			print "Could not access %s" % file
			sys.exit(1)
		root, ext = os.path.splitext(path)
		if ext == ".rpm":
			files.append(path)
	return files

# Returns a dict indexed by filename as given in the rpmlist list
def getDictByFile(rpmlist):
	headers = {}
	for file in rpmlist:
		header, isSource = getHeader(file)
		if isSource:
			print "What are you thinking?  %s is a source RPM!" % file
			sys.exit(1)
		headers[file] = header
	return headers

# Returns a dict indexed by package name.
# The dict contains a tuple of (header, filename)
def getDictByName(rpmlist):
	headers = {}
	for file in rpmlist:
		header, isSource = getHeader(file)
		name = header[rpm.RPMTAG_NAME]
		arch = header[rpm.RPMTAG_ARCH]
		if isSource:
			print "What are you thinking?  %s is a source RPM!" % file
			sys.exit(1)
		headers[(name,arch)] = (header, file)

	return headers
	
	
# Do the header compares.  Return a tuple of (newer_package_dict, missing_package_dict)
def compareUpdates(headers, updateheaders):
	"""We do the compares here and return a dict key'd on package name of
	   packages that are newer then what is in the tree"""
	   
	missing = {}
	newer = {}
	for k in updateheaders.keys():
		package, arch = k
		log("Working on package " + package)
		h = updateheaders[k]
		if headers.has_key(k):
			ret = rpm.versionCompare(headers[k][0], h[0])
			if ret == 1:
				print "Warning: Update for %s is older than package in install tree" % package
				log("Updated package %s is older.  Not doing anyhting" % package)
			elif ret == 0:
				log("%s is the same as package in install tree." % package)
			elif ret == -1:
				log("%s in updates directory is newer.  Will return in dict." % package)
				newer[k] = h
		else:
			log("%s is not present in install tree." % package)
			missing[k] = h
		
	log("Done comparing packages.")
	return (newer, missing)
			 
			 
def main():
	"""This program will scan a directory of updates, such as the Red Hat updates 
	   directory on a Red Hat FTP mirror and print out all RPMS that have not been
	   applied to the specified tree."""
	
	args = sys.argv[1:]
	global verbose

	try:
		optlist, rpmlist = getopt.getopt(args, 'hVv:r:u:e:', ['help', 'verbose', 'ver=', 'arch=', 'updates=', 'tree='])
	except getopt.error:
		usage()

	archarg=0
	verarg=0
	treearg=0
	updatesarg=0
	trees="/tmp/dumb"
	updates="/other/path"
	
	for o, a in optlist:
		if o in ("--help", "-h"):
			usage()
		if o in ("--verbose", "-V"):
			verbose = 1
		if o in ("--ver", "-v"):
			version = a
			verarg = 1
		if o in ("--arch", "-r"):
			arch = a
			archarg = 1
		if o in ("--tree", "-e"):
			trees = a
			treearg = 1
		if o in ("--updates", "-u"):
			updates = a
			updatesarg = 1
            
	if archarg+verarg+treearg+updatesarg != 4:
		print "Not enough or bad arguments."
		usage()
	
	installtree = os.path.abspath(os.path.join(trees, version, arch, "RedHat/RPMS"))
	log("installtree = " + installtree)
	updates = os.path.abspath(updates)
	log("updates directory = " + updates)
	
	if not os.path.exists(installtree):
		print "ERROR: Where's your install tree again?"
		print "%s does not exist." % installtree
		sys.exit(1)
	if not os.path.exists(updates):
		print "ERROR: Where's your updates directory?"
		print "%s does not exist." % updates
		sys.exit(1)
	
	log("Checking Files...")
	installrpms = checkFiles(os.listdir(installtree), installtree)
	updaterpms = checkFiles(os.listdir(updates), updates)
	log("Getting RPM Headers...")
	installheaders = getDictByName(installrpms)
	updateheaders = getDictByName(updaterpms)
		
	new, missing = compareUpdates(installheaders, updateheaders)
	
	print "New Packages: " + str(new.keys())
	print
	print "Missing Packages: " + str(missing.keys())
	
	print "Done!"
	
if __name__ == "__main__":
	main()