#!/usr/bin/python
# -*- coding: utf-8 -*-
# ##################################################################
#
# 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; version 2.
#
# 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.
#
# See file /usr/share/common-licenses/GPL-2 for more details.
#
# ##################################################################

import logging
import optparse
import os
import shutil
import subprocess
import sys
import tempfile

from debian.changelog import Changelog

devnull = open('/dev/null', 'r+')

def error(msg, *args, **kwargs):
    logging.error(msg, *args, **kwargs)
    sys.exit(1)

def parse(args):
    usage = 'Usage: %prog <source package> <source release> <dest release> <upload target>'
    p = optparse.OptionParser(usage)

    opts, args = p.parse_args(args)
    if len(args) != 4:
        p.error('Invalid arguments')

    return opts, args

def main(args):
    logging.basicConfig(level=logging.INFO)
    os.environ['DEB_VENDOR'] = 'Ubuntu'

    _, (package, source_release, dest_release, upload) = parse(args[1:])

    tmpdir = tempfile.mkdtemp(prefix='backportpackage-')
    try:
        for pocket in ('-updates', '-security', ''):
            if 0 == subprocess.call(['pull-lp-source', package, source_release + pocket],
                                    cwd=tmpdir,
                                    stdout=devnull, stderr=devnull):
                logging.info('Found package %s in pocket %s' % (package, source_release + pocket))
                break
        else:
            error('Unable to find package %s in release %s' % (package, source_release))

        for srcdir in os.listdir(tmpdir):
            srcdir = os.path.join(tmpdir, srcdir)
            if os.path.isdir(srcdir):
                break
        else:
            error('Something went wrong unpacking package %s' % package)

        cl = Changelog(open(os.path.join(srcdir, 'debian/changelog')))
        v = cl.get_version()

        bp_version = str(v) + ('~%s1' % dest_release)
        bp_dist = dest_release
        if upload.startswith('ppa:'):
            bp_version += '~ppa1'
        elif upload == 'ubuntu':
            bp_dist += '-backports'
        if 0 != subprocess.call(['dch',
                                 '--force-bad-version',
                                 '--preserve',
                                 '--newversion', bp_version,
                                 '--distribution', dest_release,
                                 'No-change backport to %s' % dest_release],
                                cwd=srcdir):
            error('Something went wrong updating the package changelog')
        if 0 != subprocess.call(['debuild', '-S', '-sa'],
                                cwd=srcdir):
            error('Something went wrong while building the source package')

        if ':' in bp_version:
            bp_version = bp_version[bp_version.find(':')+1:]

        print 'Please check the package in file://%s carefully' % tmpdir
        while True:
            answer = raw_input('Do you still want to upload this to %s? [Y/n] ' % upload).strip().lower()
            if answer in ('', 'y', 'yes'):
                break
            elif answer in ('n', 'no'):
                return 2
        
        if 0 != subprocess.call(['dput',
                                 upload,
                                 '%s_%s_source.changes' % (package, bp_version)],
                                cwd=tmpdir):
            error('Something went wrong uploading the package %s to %s' % package, upload)
    finally:
        shutil.rmtree(tmpdir)

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