#!/usr/bin/python
#
# (C) 2006 Guido Guenther <agx@sigxcpu.org>
#    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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# Import a new upstream version

import sys
import os
import subprocess
import tempfile
import re
import glob
from optparse import OptionParser

class CommandExecFailed:
    pass

class Command(object):
    def __init__(self, cmd, args=[]):
        self.cmd=cmd
        self.args=args

    def run(self):
        try:
            retcode = subprocess.call([self.cmd]+self.args)
            if retcode < 0:
                print >>sys.stderr, "%s was terminated by signal %d" % (self.cmd,  -retcode)
            elif retcode > 0:
                print >>sys.stderr, "%s returned %d" % (self.cmd,  retcode)
        except OSError, e:
            print >>sys.stderr, "Execution failed:", e
            retcode=1
        return retcode

    def __call__(self):
        if self.run():
            raise CommandExecFailed


class UnpackTGZ(Command):
    def __init__(self, tgz, dir):
        self.tgz=tgz
        self.dir=dir
        Command.__init__(self, 'tar', [ '-C', dir, '-zxf', tgz ])
        self.run_error="Couldn't unpack", self.tgz

class RemoveTree(Command):
    "Remove a whole directory tree"
    def __init__(self, tree):
        self.tree=tree
        Command.__init__(self, 'rm', [ '-rf', tree ])
        self.run_error="Couldn't remove ", self.tree

class Dch(Command):
    def __init__(self, version, msg):
        args=['-v', version]
        if msg:
            args.append(msg)
        Command.__init__(self, 'dch', args)
        self.run_error="Dch failed."

class GitLoadDirs(Command):
    def __init__(self, upstream_dir):
        self.upstream_dir=upstream_dir
        Command.__init__(self, 'git_load_dirs', [ self.upstream_dir ])
        self.run_error="Couldn't import %s", self.upstream_dir

class GitCommand(Command):
    "Mother/Father of all git commands"
    def __init__(self, cmd, args=[]):
        Command.__init__(self, 'git-'+cmd, args)

class GitShowBranch(GitCommand):
    def __init__(self):
        GitCommand.__init__(self,'branch')
        self.run_error="Couldn't list branches"

class GitCheckoutBranch(GitCommand):
    def __init__(self, branch):
        GitCommand.__init__(self,'checkout', [branch])
        self.branch=branch
        self.run_error="Couldn't switch to %s branch" % self.branch

class GitPull(GitCommand):
    def __init__(self, repo, branch):
        GitCommand.__init__(self,'pull', [repo, branch]) 
        self.run_error="Couldn't pull %s to %s" % (branch, repo)

class GitTag(GitCommand):
    def __init__(self, version):
        GitCommand.__init__(self,'tag', [version]) 
        self.run_error="Couldn't tag %s" % (version,)

# Used GIT Commands
gitCheckoutUpstream=GitCheckoutBranch('upstream')
gitCheckoutMaster=GitCheckoutBranch('master')
gitShowBranch=GitShowBranch()
gitPullUpstream=GitPull('.', 'upstream')

def cleanupTmpTree(tree):
    RemoveTree(tree)()


def unpackOrig(tgz):
    try:
        unpackTGZ=UnpackTGZ(tgz, tempfile.mkdtemp(dir='../'))
        unpackTGZ()
    except CommandExecFailed:
        print "Unpacking of %s failed" % (tgz,)
        cleanupTmpTree(unpackTGZ.dir)
        return
    return unpackTGZ.dir


def get_version(tgz):
    origre=re.compile('^[a-z\d-]+_(?P<version>[a-z\d\.\~\-]+)\.orig\.tar\.gz')
    m=origre.match(os.path.basename(tgz))
    if m:
        return m.group('version')    

def main():
    parser = OptionParser('%prog [-u version] /path/to/upstream-version.tar.gz')

    parser.add_option("-u", "--upstreamversion", dest="version",
                      help="Upstream Version")
    (options, args) = parser.parse_args()

    if len(args) != 1:
        parser.print_help()
        return 1
    else:
        tgz=args[0]

    try:
        os.stat('.git')
    except:
        print >>sys.stderr,"%s not a git repository" % (os.path.abspath('.'),)
        return 1

    if options.version:
        version = options.version
    else:
        version=get_version(tgz)
    if version:
        print "Upstream version is %s" % (version,)
    else:
        print >>sys.stderr,"Cannot determine upstream version from %s - use -u" % (tgz,)
        parser.print_help()
        return 1

    tmpdir=unpackOrig(tgz)
    if not tmpdir:
        return 1
    else: 
        print "Unpacked orig to %s" % (tmpdir, )
        origdir=glob.glob(tmpdir+'/*')[0]
  
    try:
        print "Importing %s to upstream branch..." % (tgz,)
        gitCheckoutUpstream()
        gitShowBranch()
        GitLoadDirs(origdir)()
        GitTag(version)()

        print "Merging to master..."
        gitCheckoutMaster()
        gitShowBranch()
        gitPullUpstream()
        Dch("%s-1" % (version,), 'New Upstream Version')()
    except CommandExecFailed:
        print >>sys.stderr, "Import of %s failed" % (tgz,)
        cleanupTmpTree(tmpdir)
        return 1
    cleanupTmpTree(tmpdir)

    print "Merged version %s of %s into ." % (version, tgz)
    return 0

if __name__ == "__main__":
    sys.exit(main())

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