#!/usr/bin/python
#
# Check components of build dependencies and warn about universe/multiverse
# ones, for a package destined for main/restricted
#
# Copyright (C) 2011 Canonical
#
# Authors:
#  Martin Pitt
#
# 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 3.
#
# 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.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

import sys
import optparse
import os.path

import apt


def check_support(apt_cache, pkgname, alt=False):
    '''Check if pkgname is in main or restricted.

    This prints messages if a package is not in main/restricted, or only
    partially (i. e. source in main, but binary in universe).
    '''
    if alt:
        prefix = '  ... alternative ' + pkgname
    else:
        prefix = ' * ' + pkgname

    try:
        pkg = apt_cache[pkgname]
    except KeyError:
        print >> sys.stderr, prefix, 'does not exist (pure virtual?)'
        return False

    section = pkg.candidate.section
    if section.startswith('universe') or section.startswith('multiverse'):
        # check if the source package is in main and thus will only need binary
        # promotion
        source_records = apt.apt_pkg.SourceRecords()
        if not source_records.lookup(pkg.candidate.source_name):
            print >> sys.stderr, 'ERROR: Cannot lookup source package for', \
                                 pkg.name
            print prefix, 'package is in', section.split('/')[0]
            return False
        src = apt.apt_pkg.TagSection(source_records.record)
        if (src['Section'].startswith('universe') or
            src['Section'].startswith('multiverse')):
            print prefix, 'binary and source package is in', \
                  section.split('/')[0]
            return False
        else:
            print prefix, 'is in', section.split('/')[0] + ', but its source', \
                  pkg.candidate.source_name, \
                  ('is already in main; file an ubuntu-archive bug for '
                   'promoting the current preferred alternative')
            return True

    if alt:
        print prefix, 'is already in main; consider preferring it'

    return True

def check_build_dependencies(apt_cache, control):
    print 'Checking support status of build dependencies...'

    any_unsupported = False

    for field in ('Build-Depends', 'Build-Depends-Indep'):
        if field not in control.section:
            continue
        for or_group in apt.apt_pkg.parse_src_depends(control.section[field]):
            pkgname = or_group[0][0]
            if not check_support(apt_cache, pkgname):
                # check non-preferred alternatives
                for altpkg in or_group[1:]:
                    if check_support(apt_cache, altpkg[0], alt=True):
                        break
                else:
                    any_unsupported = True

    return any_unsupported

def check_binary_dependencies(apt_cache, control):
    any_unsupported = False

    print '\nChecking support status of binary dependencies...'
    while True:
        try:
            control.next()
        except StopIteration:
            break

        for field in ('Depends', 'Pre-Depends', 'Recommends'):
            if field not in control.section:
                continue
            for or_group in apt.apt_pkg.parse_depends(control.section[field]):
                pkgname = or_group[0][0]
                if pkgname.startswith('$'):
                    continue
                if not check_support(apt_cache, pkgname):
                    # check non-preferred alternatives
                    for altpkg in or_group[1:]:
                        if check_support(apt_cache, altpkg[0], alt=True):
                            break
                    else:
                        any_unsupported = True

    return any_unsupported

def main():
    description = "Check if any of a package's build or binary " + \
                  "dependencies are in universe or multiverse. " + \
                  "Run this inside an unpacked source package"
    parser = optparse.OptionParser(description=description)
    parser.parse_args()
    apt_cache = apt.Cache()

    if not os.path.exists('debian/control'):
        print >> sys.stderr, ('debian/control not found. You need to run '
                              'this tool in a source package directory')
        sys.exit(1)

    # get build dependencies from debian/control
    control = apt.apt_pkg.TagFile(open('debian/control'))
    control.next()

    unsupported_build_deps = check_build_dependencies(apt_cache, control)
    unsupported_binary_deps = check_binary_dependencies(apt_cache, control)

    if unsupported_build_deps or unsupported_binary_deps:
        print ('\nPlease check https://wiki.ubuntu.com/MainInclusionProcess if '
               'this source package needs to get into in main/restricted, or '
               'reconsider if the package really needs above dependencies.')
    else:
        print 'All dependencies are supported in main or restricted.'

if __name__ == '__main__':
    main()