#!/usr/bin/python2

"""
git pre-commit hook for checking for problems with patches in RPM spec files

It verifies that:
- all patches are committed to git
- all patches are applied in %prep
- no unexpanded %patch macros exist in %prep

If any of the above checks fail, the commit is aborted.
"""

# Copyright 2013 T.C. Hollingsworth <tchollingsworth@gmail.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.

import os
import re
import rpm
import subprocess
import sys

co = subprocess.check_output

# lets check everything first and abort only at the end so packagers can fix
# everything at once
abort = False

# stash any unstaged changes
subprocess.call(['git', 'stash', '-q', '--keep-index'])

# try and read the spec and abort if RPM can't parse it
root = co(['git', 'rev-parse', '--show-toplevel']).strip()
specfile = os.path.join(root, co(['fedpkg', 'gimmespec']).strip())

try:
    specobj = rpm.TransactionSet().parseSpec(specfile)
except ValueError:
    sys.stderr.write('RPM is unable to parse the spec file, aborting commit!\n')
    sys.exit(1)

spectxt = open(specfile).read()
sources = { src[1]: src[0] for src in specobj.sources if src[2] == 1 }
patches = { src[1]: src[0] for src in specobj.sources if src[2] == 2 }

# make sure all patches are applied
patchcalls = [ int(m) for m in re.findall(r'%\{?patch([0-9]+)\}?', spectxt, re.I) ]
if re.search(r'(%\{?patches\}?|%autosetup)', spectxt) is None:
    for p in patches.iterkeys():
        if p not in patchcalls:
            sys.stderr.write('Patch #{0} not applied in %prep\n'.format(p))
            abort = True

# make sure there are no unexpanded patch macros in %prep
for p in patchcalls:
    if p not in patches:
        sys.stderr.write('Unexpanded patch #{0} macro in %prep\n'.format(p))
        abort = True

# make sure all sources and patches are committed
committed_files = [ line.split('\t')[1] for line in co(
                ['git', 'ls-tree', '--full-tree', 'HEAD']).strip().split('\n') ]
staged_files = co(['git', 'diff', '--cached', '--name-only']).strip().split('\n')
source_files = [ line.split('  ')[1] for line in open(
                os.path.join(root, 'sources')).read().strip().split('\n') ]
# could have dupes but we don't care
all_files = committed_files + staged_files + source_files

for num, url in sources.iteritems():
    if os.path.basename(url) not in all_files:
        sys.stderr.write('Source #{0} not found in lookaside cache or git\n'.format(num))
        abort = True

for num, url in patches.iteritems():
    if os.path.basename(url) not in all_files:
        sys.stderr.write('Patch #{0} not found in git or lookaside cache\n'.format(num))
        abort = True

# restore unstaged changes
subprocess.call(['git', 'stash', 'pop', '-q'])

# finally, abort the commit if that's what we want
if abort:
    sys.exit(1)