#!/usr/bin/env python

# http://users.sarai.net/shehjar/download/py-apt-tut.txt

import apt_pkg
import os
import sys

# init
apt_pkg.init()

# get caches
cache = apt_pkg.GetCache()
depcache = apt_pkg.GetDepCache(cache)

# read the pin files
depcache.ReadPinFile()
# read the synaptic pins too
#if os.path.exists(SYNAPTIC_PINFILE):
#    depcache.ReadPinFile(SYNAPTIC_PINFILE)

# init the depcache
depcache.Init()

if depcache.BrokenCount > 0:
    sys.stderr.write("E: BrokenCount > 0")
    sys.exit(-1)

depcache.Upgrade()

# version comparison function:
# http://mail.python.org/pipermail/python-list/2005-March/272909.html
for pkg in cache.Packages:
#    print pkg.Name
    if pkg.CurrentVer:
        print pkg.CurrentVer.VerStr

        #for depend in pkg.CurrentVer.DependsList.get("Depends", []):
        #    print "depends", depend,
    if depcache.MarkedInstall(pkg) or depcache.MarkedUpgrade(pkg):
        if depcache.GetCandidateVer(pkg) != pkg.CurrentVer:
            print "Update", pkg.Name
    #    sys.exit(0)

sys.exit(0)