#!/usr/bin/python

# Copyright (c) 2006, 2008 Canonical Ltd.
#
# 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 3 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, see <http://www.gnu.org/licenses/>.

# Originally written by Martin Pitt as 'syncpackage', and beaten up to
# cope with PPAs by Colin Watson.

import os
import sys
import urllib
import urlparse
import subprocess
import shutil
import pwd

import apt_pkg

tempdir = None

def ensure_tempdir():
    global tempdir
    if not tempdir:
        import tempfile
        import atexit
        tempdir = tempfile.mkdtemp(prefix='syncpackage-ppa')
        atexit.register(shutil.rmtree, tempdir)

def decompress_open(tagfile):
    if tagfile.startswith('http:') or tagfile.startswith('ftp:'):
        url = tagfile
        tagfile = urllib.urlretrieve(url)[0]

    if tagfile.endswith('.gz'):
        import gzip
        import tempfile
        ensure_tempdir()
        decompressed = tempfile.mktemp(dir=tempdir)
        fin = gzip.GzipFile(filename=tagfile)
        fout = open(decompressed, 'wb')
        fout.write(fin.read())
        fout.close()
        return open(decompressed, 'r')
    else:
        return open(tagfile, 'r')

def tagfiletodict(tagfile):
    suite = {}
    tagfileobj = decompress_open(tagfile)
    p = apt_pkg.ParseTagFile(tagfileobj)
    while p.Step() == 1:
        suite[p.Section["Package"]] = p.Section["Version"]
    tagfileobj.close()
    return suite

def retrieve_file(url):
    '''Download file (by URL)  to the current directory.

    If the file is already present, this function does nothing.'''

    fname = os.path.basename(url)
    if not os.path.exists(fname):
        print 'downloading', url
        urllib.urlretrieve(url, fname)

def dsc_getfiles(dsc):
    '''Return list of files in a .dsc file (excluding the .dsc file itself).'''

    f = open(dsc)
    files = []

    # skip until 'Files:'
    for l in f:
        if l.strip() == 'Files:':
            break

    for l in f:
        if not l.startswith(' '):
            break
        fname = l.split()[2]
        if not fname.endswith('.dsc'):
            files.append(fname)

    f.close()
    return files

#
# entry point
#

if len(sys.argv) != 4:
    print 'Usage: syncpackage <.dsc URL or path> <target release> <ppa>'
    sys.exit(1)

apt_pkg.InitSystem()

(dscurl, release, ppa) = sys.argv[1:]
dscname = os.path.basename(dscurl)
basepath = os.path.dirname(dscurl)
(srcpkg, new_ver) = dscname.split('_')
new_ver = new_ver[:-4] # strip off '.dsc'

versions = {}
base_url = 'http://ppa.launchpad.net/%s/ubuntu/dists/%s' % (ppa, release)
release_file = decompress_open('%s/Release' % base_url)
for line in release_file:
    if line.startswith('Components:'):
        for component in line.split()[1:]:
            versions.update(tagfiletodict('%s/%s/source/Sources.gz' % (base_url, component)))
release_file.close()

if srcpkg in versions:
    cur_ver = versions[srcpkg]
else:
    cur_ver = None

retrieve_file(dscurl)
files = dsc_getfiles(dscname)

# do we need the orig.tar.gz?
need_orig = True
if cur_ver is not None and cur_ver.find('-') > 0 and new_ver.find('-') > 0 and \
    cur_ver.split('-')[0] == new_ver.split('-')[0]:
    need_orig = False
    #files = [f for f in files if not f.endswith('orig.tar.gz')]

print 'Source %s: current version %s, new version %s' % (srcpkg, cur_ver, new_ver)
print 'needs orig.tar.gz', need_orig
print 'Files:', files
for f in files:
    retrieve_file(os.path.join(basepath, f))

if cur_ver is not None:
    uidx = cur_ver.find('ubuntu')
    if uidx > 0:
        cur_ver = cur_ver[:uidx]
        print 'WARNING! Overwriting modified Ubuntu version, setting current version to', cur_ver

    uidx = cur_ver.find('build')
    if uidx > 0:
        cur_ver = cur_ver[:uidx]

orig_arg = ''
if need_orig:
    orig_arg = '-sa'

# extract package, build Source
assert subprocess.call(['dpkg-source', '-x', dscname]) == 0
unpacked_dir = '%s-%s' % (srcpkg, new_ver.split('-')[0])
if 'DEBFULLNAME' in os.environ:
    uploader_name = os.environ['DEBFULLNAME']
else:
    uploader_name = pwd.getpwuid(os.getuid()).pw_gecos.split(',')[0]
uploader_email = os.environ['DEBEMAIL']
genchanges_cmd = ['dpkg-genchanges', '-q', '-S', orig_arg]
if subprocess.call(['dpkg-parsechangelog', '-v%s' % cur_ver],
                   cwd=unpacked_dir) == 0:
    genchanges_cmd.append('-v%s' % cur_ver)
genchanges_cmd.append('-e%s <%s>' % (uploader_name, uploader_email))
genchanges = subprocess.Popen(genchanges_cmd, stdout=subprocess.PIPE,
                              cwd=unpacked_dir)
changes_text = genchanges.communicate()[0]
changes_filename = '%s_%s_source.changes' % (srcpkg, new_ver)
changes_file = open(changes_filename, 'w')
print >>changes_file, 'Origin: %s' % urlparse.urlparse(dscurl).netloc
for line in changes_text.splitlines():
    if line.startswith('Distribution:'):
        line = 'Distribution: %s' % release
    print >>changes_file, line
changes_file.close()
shutil.rmtree(srcpkg + '-' + new_ver.split('-')[0], True)

# strip any previous .dsc signature
dsc_file = open(dscname)
dsc_lines = [line.rstrip('\n') for line in dsc_file.readlines()]
dsc_file.close()
if dsc_lines[0] == '-----BEGIN PGP SIGNED MESSAGE-----':
    while dsc_lines and dsc_lines[0] != '':
        dsc_lines.pop(0)
    dsc_lines.pop(0)
    try:
        blank = dsc_lines.index('')
        dsc_lines = dsc_lines[:blank]
    except ValueError:
        pass
dsc_file = open(dscname, 'w')
for line in dsc_lines:
    print >>dsc_file, line
dsc_file.close()

assert subprocess.call(['debsign', changes_filename]) == 0

dput_cf = '%s_%s_source.dput' % (srcpkg, new_ver)
dput_cf_file = open(dput_cf, 'w')
print >>dput_cf_file, '''\
[ppa-%s]
fqdn = ppa.launchpad.net
method = ftp
incoming = ~%s/ubuntu/
login = anonymous
allow_unsigned_uploads = 0''' % (ppa, ppa)
dput_cf_file.close()
assert subprocess.call(['dput', '-c', dput_cf, 'ppa-%s' % ppa, changes_filename]) == 0
os.unlink(dput_cf)