# bzr.py - bzr support for the convert extension

#

#  Copyright 2008, 2009 Marek Kubica <marek@xivilization.net> and others

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2, incorporated herein by reference.

# This module is for handling 'bzr', that was formerly known as Bazaar-NG;

# it cannot access 'bar' repositories, but they were never used very much

import os

from mercurial import demandimport

# these do not work with demandimport, blacklist

demandimport.ignore.extend([

        'bzrlib.transactions',

        'bzrlib.urlutils',

    ])

from mercurial.i18n import _

from mercurial import util

from common import NoRepo, commit, converter_source

try:

    # bazaar imports

    from bzrlib import branch, revision, errors

    from bzrlib.revisionspec import RevisionSpec

except ImportError:

    pass

supportedkinds = ('file', 'symlink')

class bzr_source(converter_source):

    """Reads Bazaar repositories by using the Bazaar Python libraries"""

    def __init__(self, ui, path, rev=None):

        super(bzr_source, self).__init__(ui, path, rev=rev)

        if not os.path.exists(os.path.join(path, '.bzr')):

            raise NoRepo('%s does not look like a Bazaar repo' % path)

        try:

            # access bzrlib stuff

            branch

        except NameError:

            raise NoRepo('Bazaar modules could not be loaded')

        path = os.path.abspath(path)

        self.branch = branch.Branch.open(path)

        self.sourcerepo = self.branch.repository

        self._parentids = {}

    def before(self):

        """Before the conversion begins, acquire a read lock

        for all the operations that might need it. Fortunately

        read locks don't block other reads or writes to the

        repository, so this shouldn't have any impact on the usage of

        the source repository.

        The alternative would be locking on every operation that

        needs locks (there are currently two: getting the file and

        getting the parent map) and releasing immediately after,

        but this approach can take even 40% longer."""

        self.sourcerepo.lock_read()

    def after(self):

        self.sourcerepo.unlock()

    def getheads(self):

        if not self.rev:

            return [self.branch.last_revision()]

        try:

            r = RevisionSpec.from_string(self.rev)

            info = r.in_history(self.branch)

        except errors.BzrError:

            raise util.Abort(_('%s is not a valid revision in current branch')

                             % self.rev)

        return [info.rev_id]

    def getfile(self, name, rev):

        revtree = self.sourcerepo.revision_tree(rev)

        fileid = revtree.path2id(name)

        if fileid is None or revtree.kind(fileid) not in supportedkinds:

            # the file is not available anymore - was deleted

            raise IOError(_('%s is not available in %s anymore') %

                    (name, rev))

        sio = revtree.get_file(fileid)

        return sio.read()

    def getmode(self, name, rev):

        return self._modecache[(name, rev)]

    def getchanges(self, version):

        # set up caches: modecache and revtree

        self._modecache = {}

        self._revtree = self.sourcerepo.revision_tree(version)

        # get the parentids from the cache

        parentids = self._parentids.pop(version)

        # only diff against first parent id

        prevtree = self.sourcerepo.revision_tree(parentids[0])

        return self._gettreechanges(self._revtree, prevtree)

    def getcommit(self, version):

        rev = self.sourcerepo.get_revision(version)

        # populate parent id cache

        if not rev.parent_ids:

            parents = []

            self._parentids[version] = (revision.NULL_REVISION,)

        else:

            parents = self._filterghosts(rev.parent_ids)

            self._parentids[version] = parents

        return commit(parents=parents,

                author=self.recode(rev.committer),

                # bzr returns bytestrings or unicode, depending on the content

                desc=self.recode(rev.message),

                rev=version)

    def gettags(self):

        if not self.branch.supports_tags():

            return {}

        tagdict = self.branch.tags.get_tag_dict()

        bytetags = {}

        for name, rev in tagdict.iteritems():

            bytetags[self.recode(name)] = rev

        return bytetags

    def getchangedfiles(self, rev, i):

        self._modecache = {}

        curtree = self.sourcerepo.revision_tree(rev)

        if i is not None:

            parentid = self._parentids[rev][i]

        else:

            # no parent id, get the empty revision

            parentid = revision.NULL_REVISION

        prevtree = self.sourcerepo.revision_tree(parentid)

        changes = [e[0] for e in self._gettreechanges(curtree, prevtree)[0]]

        return changes

    def _gettreechanges(self, current, origin):

        revid = current._revision_id;

        changes = []

        renames = {}

        for (fileid, paths, changed_content, versioned, parent, name,

            kind, executable) in current.iter_changes(origin):

            if paths[0] == u'' or paths[1] == u'':

                # ignore changes to tree root

                continue

            # bazaar tracks directories, mercurial does not, so

            # we have to rename the directory contents

            if kind[1] == 'directory':

                if kind[0] not in (None, 'directory'):

                    # Replacing 'something' with a directory, record it

                    # so it can be removed.

                    changes.append((self.recode(paths[0]), revid))

                if None not in paths and paths[0] != paths[1]:

                    # neither an add nor an delete - a move

                    # rename all directory contents manually

                    subdir = origin.inventory.path2id(paths[0])

                    # get all child-entries of the directory

                    for name, entry in origin.inventory.iter_entries(subdir):

                        # hg does not track directory renames

                        if entry.kind == 'directory':

                            continue

                        frompath = self.recode(paths[0] + '/' + name)

                        topath = self.recode(paths[1] + '/' + name)

                        # register the files as changed

                        changes.append((frompath, revid))

                        changes.append((topath, revid))

                        # add to mode cache

                        mode = ((entry.executable and 'x') or (entry.kind == 'symlink' and 's')

                                or '')

                        self._modecache[(topath, revid)] = mode

                        # register the change as move

                        renames[topath] = frompath

                # no futher changes, go to the next change

                continue

            # we got unicode paths, need to convert them

            path, topath = [self.recode(part) for part in paths]

            if topath is None:

                # file deleted

                changes.append((path, revid))

                continue

            # renamed

            if path and path != topath:

                renames[topath] = path

                changes.append((path, revid))

            # populate the mode cache

            kind, executable = [e[1] for e in (kind, executable)]

            mode = ((executable and 'x') or (kind == 'symlink' and 'l')

                    or '')

            self._modecache[(topath, revid)] = mode

            changes.append((topath, revid))

        return changes, renames

    def _filterghosts(self, ids):

        """Filters out ghost revisions which hg does not support, see

        <http://bazaar-vcs.org/GhostRevision>

        """

        parentmap = self.sourcerepo.get_parent_map(ids)

        parents = tuple([parent for parent in ids if parent in parentmap])

        return parents

    def recode(self, s, encoding=None):

        """This version of recode tries to encode unicode to bytecode,

        and preferably using the UTF-8 codec.

        Other types than Unicode are silently returned, this is by

        intention, e.g. the None-type is not going to be encoded but instead

        just passed through

        """

        if not encoding:

            encoding = self.encoding or 'utf-8'

        if isinstance(s, unicode):

            return s.encode(encoding)

        else:

            # leave it alone

            return s