# vim: set fileencoding=utf-8 :
#
# (C) 2006, 2007, 2011, 2012, 2015-2017 Guido Günther <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, please see
#    <http://www.gnu.org/licenses/>
"""Import a Debian source package into a Git repository"""

import sys
import re
import os
import shutil
import tempfile
import glob
import pipes
import time
import gbp.command_wrappers as gbpc
from gbp.deb.dscfile import DscFile
from gbp.deb.upstreamsource import DebianUpstreamSource, unpack_component_tarball
from gbp.deb.git import (DebianGitRepository, GitRepositoryError)
from gbp.deb.changelog import ChangeLog
from gbp.git import rfc822_date_to_git
from gbp.git.modifier import GitModifier
from gbp.git.vfs import GitVfs
from gbp.config import (GbpOptionParserDebian, GbpOptionGroup,
                        no_upstream_branch_msg)
from gbp.errors import GbpError
from gbp.scripts.common import ExitCodes, debug_exc
from gbp.scripts.common import repo_setup
import gbp.log


class SkipImport(Exception):
    pass


def download_source(pkg, dirs, unauth):
    opts = ['--download-only']
    if unauth:
        opts.append('--allow-unauthenticated')

    if re.match(r'[a-z]{1,5}://', pkg):
        cmd = 'dget'
        opts += ['-q', pkg]
    else:
        cmd = 'apt-get'
        opts += ['-qq', 'source', pkg]

    dirs['download'] = os.path.abspath(tempfile.mkdtemp())
    gbp.log.info("Downloading '%s' using '%s'..." % (pkg, cmd))

    gbpc.RunAtCommand(cmd, opts, shell=False)(dir=dirs['download'])
    try:
        dsc = glob.glob(os.path.join(dirs['download'], '*.dsc'))[0]
    except IndexError:
        raise GbpError("Did not find a dsc file at %s/" % dirs['download'])
    return dsc


def apply_patch(diff):
    "Apply patch to a source tree"
    patch_opts = ['-N', '-p1', '-F0', '-u', '-t',
                  '-Vnever', '-g0', '-z.gbp.orig',
                  '--quiet']

    pipe = pipes.Template()
    pipe.prepend('gunzip -c %s' % diff, '.-')
    pipe.append('patch %s' % ' '.join(patch_opts), '-.')

    try:
        ret = pipe.copy('', '')
        if ret:
            raise GbpError("Error import %s: %d" % (diff, ret))
    except OSError as err:
        raise GbpError("Error importing %s: %s" % (diff, err[0]))


def apply_deb_tgz(deb_tgz, filters):
    """Apply .debian.tar.gz (V3 source format)"""
    # Remove any existing data in debian/ as dpkg-source -x does
    if os.path.isdir('debian'):
        shutil.rmtree('debian')
    gbpc.UnpackTarArchive(deb_tgz, ".", filters)()


def get_changes(dir, repo, debian_branch):
    if repo.empty:
        version = "0~"
    else:
        vfs = GitVfs(repo, debian_branch)
        try:
            with vfs.open('debian/changelog') as f:
                version = ChangeLog(contents=f.read()).version
        except IOError:
            version = "0~"  # Use full history if debian branch has no changelog
    cl = ChangeLog(filename=os.path.join(dir, 'debian/changelog'))
    return cl.get_changes(version)


def get_author_from_changelog(dir):
    """
    Get author from debian/changelog
    """
    dch = ChangeLog(filename=os.path.join(dir, 'debian/changelog'))
    date = rfc822_date_to_git(dch.date, fuzzy=True)
    if not (dch.author or dch.email):
        gbp.log.warn("Failed to parse maintainer")

    return GitModifier(dch.author, dch.email, date)


def get_committer_from_author(author, options):
    """
    Based on the options fill in the committer
    """
    committer = GitModifier()
    if options.author_committer:
        committer.name = author.name
        committer.email = author.email
    if options.author_committer_date:
        committer.date = author.date
    return committer


def check_parents(repo, branch, tag):
    """
    Check if the upstream tag is already merged, if not, return
    the additional parent to merge
    """
    parents = None
    rev = None

    try:
        rev = repo.rev_parse("%s^{commit}" % tag)
    except GitRepositoryError:
        pass

    if rev and not repo.branch_contains(branch, rev):
        gbp.log.debug("Tag '%s' not yet merged into '%s'"
                      % (tag, branch))
        parents = [rev]

    return parents


def apply_debian_patch(repo, source, dsc, upstream_commit, options):
    """apply the debian patch and tag appropriately"""

    try:
        os.chdir(source.unpacked)

        if dsc.diff:
            apply_patch(dsc.diff)
        elif dsc.deb_tgz:
            apply_deb_tgz(dsc.deb_tgz, options.filters)
        else:
            raise GbpError("Neither a Debian diff nor tarball found")

        if os.path.exists('debian/rules'):
            os.chmod('debian/rules', 0o755)
        os.chdir(repo.path)

        parents = check_parents(repo, options.debian_branch, upstream_commit)
        author = get_author_from_changelog(source.unpacked)
        committer = get_committer_from_author(author, options)

        changes = get_changes(source.unpacked,
                              repo,
                              options.debian_branch)
        commit_msg = "Import Debian changes %s\n%s" % (dsc.version, changes)
        commit = repo.commit_dir(source.unpacked,
                                 commit_msg,
                                 branch=options.debian_branch,
                                 other_parents=parents,
                                 author=author,
                                 committer=committer)
        if not options.skip_debian_tag:
            repo.create_tag(repo.version_to_tag(options.debian_tag, dsc.version),
                            msg="Debian release %s" % dsc.version,
                            commit=commit,
                            sign=options.sign_tags,
                            keyid=options.keyid)
    except (gbpc.CommandExecFailed, GitRepositoryError) as err:
        msg = str(err) or 'Unknown error, please report a bug'
        raise GbpError("Failed to import Debian package: %s" % msg)
    finally:
        os.chdir(repo.path)


def create_missing_branch(repo, branch, options):
    if not repo.has_branch(branch):
        if options.create_missing_branches:
            gbp.log.info("Creating missing branch '%s'" % branch)
            repo.create_branch(branch)
        else:
            raise GbpError(no_upstream_branch_msg % branch +
                           "\nAlso check the --create-missing-branches option.")


def import_native(repo, source, dsc, options):
    tag = repo.version_to_tag(options.debian_tag, dsc.upstream_version)
    msg = "Debian version %s" % dsc.upstream_version

    gbp.log.info("Tag %s not found, importing Debian tarball" % tag)
    if repo.empty:
        branch = None
    else:
        branch = options.debian_branch
        create_missing_branch(repo, branch, options)

    author = get_author_from_changelog(source.unpacked)
    committer = get_committer_from_author(author, options)
    commit_msg = "Import %s\n%s" % (msg, get_changes(source.unpacked,
                                                     repo,
                                                     options.debian_branch))
    commit = repo.commit_dir(source.unpacked,
                             commit_msg,
                             branch,
                             author=author,
                             committer=committer)
    if not options.skip_debian_tag:
        repo.create_tag(name=tag,
                        msg=msg,
                        commit=commit,
                        sign=options.sign_tags,
                        keyid=options.keyid)
    if repo.empty and not repo.has_branch(options.debian_branch):
        repo.create_branch(options.debian_branch, commit)
    return commit


def import_upstream(repo, source, dsc, options):
    tag = repo.version_to_tag(options.upstream_tag, dsc.upstream_version)
    msg = "Upstream version %s" % dsc.upstream_version

    if repo.empty:
        branch = None
    else:
        branch = options.upstream_branch
        create_missing_branch(repo, branch, options)

    author = committer = {}
    commit_msg = "Import %s" % msg

    upstream_parent = repo.vcs_tag_parent(options.vcs_tag,
                                          dsc.upstream_version)
    commit = repo.commit_dir(source.unpacked,
                             commit_msg,
                             branch,
                             other_parents=upstream_parent,
                             author=author,
                             committer=committer)

    # if the repo was just created make sure debian branch is in .git/HEAD
    # and upstream points to the first commit
    if repo.empty:
        if repo.branch != options.debian_branch:
            repo.rename_branch(repo.branch, options.debian_branch)
        repo.create_branch(options.upstream_branch, options.debian_branch)

    repo.create_tag(name=tag,
                    msg=msg,
                    commit=commit,
                    sign=options.sign_tags,
                    keyid=options.keyid)
    return commit


def print_dsc(dsc):
    if dsc.native:
        gbp.log.debug("Debian Native Package")
        gbp.log.debug("Version: %s" % dsc.upstream_version)
        gbp.log.debug("Debian tarball: %s" % dsc.tgz)
    else:
        gbp.log.debug("Upstream version: %s" % dsc.upstream_version)
        gbp.log.debug("Debian version: %s" % dsc.debian_version)
        gbp.log.debug("Upstream tarball: %s" % dsc.tgz)
        if dsc.additional_tarballs:
            gbp.log.debug("Additional tarballs: %s" % ", ".join(dsc.additional_tarballs.values()))
        if dsc.diff:
            gbp.log.debug("Debian patch: %s" % dsc.diff)
        if dsc.deb_tgz:
            gbp.log.debug("Debian patch: %s" % dsc.deb_tgz)
    if dsc.epoch:
        gbp.log.debug("Epoch: %s" % dsc.epoch)


def move_tag_stamp(repo, format, version):
    "Move tag out of the way appending the current timestamp"
    old = repo.version_to_tag(format, version)
    timestamped = "%s~%s" % (version, int(time.time()))
    new = repo.version_to_tag(format, timestamped)
    repo.move_tag(old, new)


def disable_pristine_tar(options, reason):
    """Disable pristine tar if enabled"""
    if options.pristine_tar:
        gbp.log.info("%s: setting '--no-pristine-tar' option" % reason)
        options.pristine_tar = False


def build_parser(name):
    try:
        parser = GbpOptionParserDebian(command=os.path.basename(name), prefix='',
                                       usage='%prog [options] /path/to/package.dsc [target]')
    except GbpError as err:
        gbp.log.err(err)
        return None

    import_group = GbpOptionGroup(parser, "import options",
                                  "pristine-tar and filtering")
    tag_group = GbpOptionGroup(parser, "tag options",
                               "options related to git tag creation")
    branch_group = GbpOptionGroup(parser, "version and branch naming options",
                                  "version number and branch layout options")
    for group in [import_group, branch_group, tag_group]:
        parser.add_option_group(group)

    parser.add_option("-v", "--verbose", action="store_true", dest="verbose", default=False,
                      help="verbose command execution")
    parser.add_config_file_option(option_name="color", dest="color", type='tristate')
    parser.add_config_file_option(option_name="color-scheme",
                                  dest="color_scheme")
    branch_group.add_config_file_option(option_name="debian-branch",
                                        dest="debian_branch")
    branch_group.add_config_file_option(option_name="upstream-branch",
                                        dest="upstream_branch")
    branch_group.add_boolean_config_file_option(option_name="create-missing-branches",
                                                dest="create_missing_branches")
    branch_group.add_config_file_option(option_name="upstream-vcs-tag", dest="vcs_tag")

    tag_group.add_boolean_config_file_option(option_name="sign-tags",
                                             dest="sign_tags")
    tag_group.add_config_file_option(option_name="keyid",
                                     dest="keyid")
    tag_group.add_config_file_option(option_name="debian-tag",
                                     dest="debian_tag")
    tag_group.add_config_file_option(option_name="upstream-tag",
                                     dest="upstream_tag")
    tag_group.add_option("--skip-debian-tag", dest="skip_debian_tag",
                         action="store_true", default=False,
                         help="Don't add a tag after importing the Debian patch")

    import_group.add_config_file_option(option_name="filter",
                                        dest="filters", action="append")
    import_group.add_boolean_config_file_option(option_name="pristine-tar",
                                                dest="pristine_tar")
    import_group.add_option("--allow-same-version", action="store_true",
                            dest="allow_same_version", default=False,
                            help="allow import of already imported version")
    import_group.add_boolean_config_file_option(option_name="author-is-committer",
                                                dest="author_committer")
    import_group.add_boolean_config_file_option(option_name="author-date-is-committer-date",
                                                dest="author_committer_date")
    import_group.add_boolean_config_file_option(option_name="allow-unauthenticated",
                                                dest="allow_unauthenticated")

    parser.add_config_file_option(option_name="repo-user", dest="repo_user",
                                  choices=['DEBIAN', 'GIT'])
    parser.add_config_file_option(option_name="repo-email", dest="repo_email",
                                  choices=['DEBIAN', 'GIT'])
    parser.add_option("--download", dest='download', action="store_true",
                      default=False, help="Ignored. Accepted for compatibility; see EXAMPLES in gbp-import-dsc(1).")
    return parser


def parse_args(argv):
    parser = build_parser(argv[0])
    if not parser:
        return None, None

    (options, args) = parser.parse_args(argv[1:])
    gbp.log.setup(options.color, options.verbose, options.color_scheme)

    if options.download:
        gbp.log.warn("Passing --download explicitly is deprecated.")

    return options, args


def is_download(pkg):
    """
    >>> is_download("http://foo.example.com/apackage.dsc")
    (True, 'http://foo.example.com/apackage.dsc')
    >>> is_download("apt:///apackage/sid")
    (True, 'apackage/sid')
    >>> is_download("apt://apackage/sid")
    (True, 'apackage/sid')
    >>> is_download("apt:apackage/sid")
    (True, 'apackage/sid')
    >>> is_download("apt_1.0_amd64.dsc")
    (False, 'apt_1.0_amd64.dsc')
    >>> is_download("file:///foo/apackage.dsc")
    (False, '/foo/apackage.dsc')
    """
    if pkg.startswith('file://'):
        return (False, pkg[len('file://'):])
    elif pkg.startswith('apt:'):
        return (True, re.match(r'apt:([/]{2,3})?(?P<pkg>.*)', pkg).group('pkg'))
    elif re.match("[a-z]{1,5}://", pkg):
        return (True, pkg)
    return (False, pkg)


def parse_all(argv):
    options, args = parse_args(argv)
    if not options:
        return None, None, None

    if len(args) == 1:
        pkg = args[0]
        target = None
    elif len(args) == 2:
        pkg = args[0]
        target = args[1]
    else:
        gbp.log.err("Need to give exactly one package to import. Try --help.")
        return None, None, None

    download, pkg = is_download(pkg)
    # honor options.download until removed
    options.download = download or options.download
    return options, pkg, target


def main(argv):
    dirs = dict(top=os.path.abspath(os.curdir))
    needs_repo = False
    ret = 1
    skipped = False

    options, pkg, target = parse_all(argv)
    if not options:
        return ExitCodes.parse_error

    try:
        try:
            repo = DebianGitRepository('.')
            # remember if the was repo initially empty
            repo.empty = repo.is_empty()

            (clean, out) = repo.is_clean()
            if not clean and not repo.empty:
                raise GbpError("Repository has uncommitted changes, commit these first: %s" % out)
        except GitRepositoryError:
            # no repo found, create one
            needs_repo = True

        if options.download:
            dscfile = download_source(pkg,
                                      dirs=dirs,
                                      unauth=options.allow_unauthenticated)
        else:
            dscfile = pkg

        dsc = DscFile.parse(dscfile)
        if dsc.pkgformat not in ['1.0', '3.0']:
            raise GbpError("Importing %s source format not yet supported." % dsc.pkgformat)
        if options.verbose:
            print_dsc(dsc)

        if needs_repo:
            target = target or dsc.pkg
            if os.path.exists(target):
                raise GbpError("Directory '%s' already exists. If you want to import into it, "
                               "please change into this directory otherwise move it away first."
                               % target)
            gbp.log.info("No git repository found, creating one.")
            repo = DebianGitRepository.create(target)
            repo.empty = True
            os.chdir(repo.path)
            repo_setup.set_user_name_and_email(options.repo_user, options.repo_email, repo)

        if repo.bare:
            disable_pristine_tar(options, "Bare repository")

        # unpack
        dirs['tmp'] = os.path.abspath(tempfile.mkdtemp(dir='..'))
        source = DebianUpstreamSource(dsc.tgz)
        source.unpack(dirs['tmp'], options.filters)
        for (component, tarball) in dsc.additional_tarballs.items():
            gbp.log.info("Found component tarball '%s'" % os.path.basename(tarball))
            unpack_component_tarball(source.unpacked, component, tarball, options.filters)

        if repo.find_version(options.debian_tag, dsc.version):
            gbp.log.warn("Version %s already imported." % dsc.version)
            if options.allow_same_version:
                gbp.log.info("Moving tag of version '%s' since import forced" % dsc.version)
                move_tag_stamp(repo, options.debian_tag, dsc.version)
            else:
                raise SkipImport

        # import
        if dsc.native:
            import_native(repo, source, dsc, options)
        else:
            imported = False
            commit = repo.find_version(options.upstream_tag, dsc.upstream_version)
            if not repo.find_version(options.upstream_tag, dsc.upstream_version):
                commit = import_upstream(repo, source, dsc, options)
                imported = True

            if not repo.has_branch(options.debian_branch):
                if options.create_missing_branches:
                    repo.create_branch(options.debian_branch, commit)
                else:
                    raise GbpError("Branch %s does not exist, use --create-missing-branches" %
                                   options.debian_branch)

            if dsc.diff or dsc.deb_tgz:
                apply_debian_patch(repo, source, dsc, commit, options)
            else:
                gbp.log.warn("Didn't find a diff to apply.")

            if imported and options.pristine_tar:
                repo.create_pristine_tar_commits(commit,
                                                 dsc.tgz,
                                                 dsc.additional_tarballs.items())

        if repo.get_branch() == options.debian_branch or repo.empty:
            # Update HEAD if we modified the checked out branch
            repo.force_head(options.debian_branch, hard=True)
        ret = 0
    except KeyboardInterrupt:
        gbp.log.err("Interrupted. Aborting.")
    except gbpc.CommandExecFailed:
        pass  # command itself printed an error
    except GitRepositoryError as msg:
        gbp.log.err("Git command failed: %s" % msg)
        debug_exc(options)
    except GbpError as err:
        if str(err):
            gbp.log.err(err)
        debug_exc(options)
    except SkipImport:
        skipped = True
        ret = 0
    finally:
        os.chdir(dirs['top'])
        for d in ['tmp', 'download']:
            if d in dirs:
                gbpc.RemoveTree(dirs[d])()

    if not ret and not skipped:
        gbp.log.info("Version '%s' imported under '%s'" % (dsc.version, repo.path))
    return ret


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

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