#!/usr/bin/python
# vim: set fileencoding=utf-8 :
#
# (C) 2007 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
#
"""Generate Debian changelog entries from git changelogs"""

import sys
import os
import re
import subprocess
import gbp.command_wrappers as gbpc
from gbp.git_utils import (GitRepositoryError, GitRepository, build_tag)
from gbp.config import GbpOptionParser
from gbp.errors import GbpError
from gbp.deb_utils import parse_changelog


def get_log(start, end):
    """Get the shortlog from commit start to commit end"""
    try:
        p1 = subprocess.Popen(["git-log", "--no-merges", "%s...%s" % (start, end)], 
                              stdout=subprocess.PIPE)
        p2 = subprocess.Popen(["git-shortlog"], stdin=p1.stdout, stdout=subprocess.PIPE)
        changes = p2.communicate()[0].split('\n')
    except OSError, err:
        raise GbpError, "Cannot get changes: %s" % err
    except ValueError, err:
        raise GbpError, "Cannot get changes: %s" % err
    if p1.wait() or p2.wait():
        raise GbpError, "Cannot get changes, pipe failed."
    return changes


def shortlog_to_dch(changes, verbose):
    """convert the changes in git shortlog format to debian changelog format"""    
    commit_re = re.compile('\s+(?P<msg>.*)')
    author_re = re.compile('(?P<author>.*) \([0-9]+\)')
    author = 'Unknown'
    ret = 0

    # FIXME: this isn't flexible enough
    ret = os.system("dch --distribution=UNRELEASED -i UNRELEASED")
    if ret:
        raise GbpError, "Error executing %s: %d" % (cmd, ret)

    for line in changes:
        r = commit_re.match(line)
        msg = ''
        if r:
            msg = r.group('msg')
        else:
            r = author_re.match(line)
            if r:
                author = r.group('author')
            elif line:
                print >>sys.stderr, "Unknown changelog line: %s" % line
        if msg:
            cmd = 'DEBFULLNAME="%s" dch "%s"' % (author, msg.replace('"','\"'))
            if verbose:
                print cmd
            ret = os.system(cmd)
            if ret:
                raise GbpError, "Error executing %s: %d" % (cmd, ret)


def main(argv):
    ret = 0

    parser = GbpOptionParser(command=os.path.basename(argv[0]), prefix='')

    parser.add_option("-v", "--verbose", action="store_true", dest="verbose", default=False,
                      help="verbose command execution")
    parser.add_config_file_option(option_name="debian-branch", dest='debian',
                      help="branch the debian patch is being developed on, default is '%(debian-branch)s'")
    parser.add_option("-s", "--since", dest="from_commit", help="commit to start from")
    parser.add_config_file_option(option_name="debian-tag", dest="debian_tag",
                      help="Format string for debian tags, default is '%(debian-tag)s'")
    (options, args) = parser.parse_args(argv[1:])

    try:
        if options.verbose:
            gbpc.Command.verbose = True

        if args:
            parser.print_help()
            raise GbpError

        try:
            GitRepository('.')
        except GitRepositoryError:
            raise GbpError, "%s is not a git repository" % (os.path.abspath('.'))

        if options.from_commit:
            start = options.from_commit	 
        else:
            cp = parse_changelog('debian/changelog')	
            start = build_tag(options.debian_tag, cp['Version'])

        changes = get_log(start, options.debian)
	if changes:
            shortlog_to_dch(changes, options.verbose)
	else:
	    print "No changes detected from %s to %s." % (start, options.debian)

    except GbpError, err:
        if len(err.__str__()):
            print >>sys.stderr, err
        ret = 1
    return ret

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

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