#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# rpmdev-vercmp -- compare rpm versions
#
# Copyright (c) Seth Vidal, Ville Skyttä
#
# 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

import sys

import rpm


def usage():
    print ("""
rpmdev-vercmp <epoch1> <ver1> <release1> <epoch2> <ver2> <release2>
rpmdev-vercmp <EVR1> <EVR2>
rpmdev-vercmp # with no arguments, prompt

Exit status is 0 if the EVR's are equal, 11 if EVR1 is newer, and 12 if EVR2
is newer.  Other exit statuses indicate problems.
""")

def askforstuff(thingname):
    thing = raw_input('%8s: ' % thingname)
    return thing

# from yum and rpmlint, with less internal assumptions, and returning
# empty strings instead of None for missing bits
def stringToEVR(verstring):
    if verstring in (None, ''):
        return ('', '', '')
    i = verstring.find(':')
    if i == -1:
        epoch = ''
    else:
        epoch = verstring[:i]
    i += 1
    j = verstring.find('-', i)
    if j == -1:
        version = verstring[i:]
        release = ''
    else:
        version = verstring[i:j]
        release = verstring[j+1:]
    return (epoch, version, release)

def main():
    if len(sys.argv) > 1 and \
            sys.argv[1] in ('-h', '--help', '-help', '--usage'):
        usage()
        sys.exit(0)
    elif len(sys.argv) == 3:
        (e1, v1, r1) = stringToEVR(sys.argv[1])
        (e2, v2, r2) = stringToEVR(sys.argv[2])
    elif len(sys.argv) < 7:
        e1 = askforstuff('Epoch1')
        v1 = askforstuff('Version1')
        r1 = askforstuff('Release1')        
        e2 = askforstuff('Epoch2')
        v2 = askforstuff('Version2')
        r2 = askforstuff('Release2')
    else:
        (e1, v1, r1, e2, v2, r2) = sys.argv[1:]

    evr1 = '%s%s%s' % (e1 and e1 + ':' or '', v1 or '', r1 and '-' + r1 or '')
    evr2 = '%s%s%s' % (e2 and e2 + ':' or '', v2 or '', r2 and '-' + r2 or '')
    
    rc = rpm.labelCompare((e1 or None, v1 or None, r1 or None),
                          (e2 or None, v2 or None, r2 or None))
    fmt = '%s == %s'
    if rc > 0:
        fmt = '%s > %s'
        rc = 11
    elif rc < 0:
        fmt = '%s < %s'
        rc = 12
    print (fmt % (evr1, evr2))
    sys.exit(rc)

if __name__ == "__main__":
    main()