#!/usr/bin/python -tt

import sys
import tempfile
import rpm
import subprocess
import os
import glob
import yum

def return_binary_pkgs_from_srpm(srpmfn):
    mydir = tempfile.mkdtemp()
    binary_pkgs = []
    rc = subprocess.Popen(['rpm2cpio', srpmfn],stdout=subprocess.PIPE)
    cs = subprocess.Popen(['cpio', '--quiet', '-i', '*.spec'], cwd=mydir,
                          stdin=rc.stdout, stdout=subprocess.PIPE, stderr=open('/dev/null', 'w'))
    output = cs.communicate()[0]
    specs = glob.glob(mydir + '/*.spec')
    if not specs:
        return binary_pkgs
    spkg = rpm.spec(specs[0])
    for p in spkg.packages:
        binary_pkgs.append(p.header['name'])
    return binary_pkgs



import yum
my = yum.YumBase()
my.preconf.init_plugins=False
my.setCacheDir()

srpms = sys.argv[1:]
build_reqs = {}
build_bin = {}
srpms_to_pkgs = {}


for i in srpms:
    # generate the list of binpkgs the srpms create 
    build_bin[i] = return_binary_pkgs_from_srpm(i)

    # generate the list of provides in the repos we know about from those binpkgs (if any)
    p_names = []
    for name in build_bin[i]:
        providers = my.pkgSack.searchNevra(name=name)
        if providers:
            p_names.extend(providers[0].provides_names)
    build_bin[i].extend(p_names)

    # setup the build_reqs
    build_reqs[i] = []

for i in srpms:
    # go through each srpm and take its buildrequires and resolve them out to one of other
    # srpms, if possible using the build_bin list we just generated
    # toss out any pkg which doesn't map back - this only does requires NAMES - not versions
    # so don't go getting picky about versioning here.
    lp = yum.packages.YumLocalPackage(filename=i)
    srpms_to_pkgs[i] = lp
    for r in lp.requires_names:
        for srpm in build_bin:
            if r in build_bin[srpm]:
                build_reqs[i].append(srpm)


# output the results in a format tsort(1) can cope with
for (pkg,reqlist) in build_reqs.items():
    for req in reqlist:
        print '%s %s' % (pkg, req)