#!/usr/bin/env python

import os
import sys

import rpm
import struct

def readHeader(filename):
    fd = os.open(filename, os.O_RDONLY)
    h = ts.hdrFromFdno(fd)
    os.close(fd)
    return h

def writeLead(filename, type, name, version, release):
    fd = os.open(filename, os.O_RDWR)

    # rpmlead.type
    buf = struct.pack("!H", type)
    assert(len(buf) == 2)
    os.lseek(fd, 6, 0)
    os.write(fd, buf)

    # rpmlead.name
    buf = "%s-%s-%s" % (name, version, release)
    if len(buf) > 64: buf = buf[0:64]
    os.lseek(fd, 10, 0)
    os.write(fd, buf)

    os.close(fd)

RPMLEAD_BINARY = 0
RPMLEAD_SOURCE = 1

ts = rpm.TransactionSet()

for arg in sys.argv[1:]:
    statinfo = os.stat(arg)

    hdr = readHeader(arg)
    if hdr[rpm.RPMTAG_SOURCEPACKAGE]:
        leadtype = RPMLEAD_SOURCE
    else:
        if (hdr[rpm.RPMTAG_SOURCERPM] and
            hdr[rpm.RPMTAG_SOURCERPM] != '(none)'):
            leadtype = RPMLEAD_BINARY
        else:
            leadtype = RPMLEAD_SOURCE
    writeLead(arg, leadtype,
              hdr['name'], hdr['version'], hdr['release'])

    os.utime(arg, (statinfo[7], statinfo[8]))