# __init__.py - topic extension

#

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

# GNU General Public License version 2 or any later version.

"""Adds topic branches. Topic branches are lightweight branches which

dissappear when changes are finalized.

This is sort of similar to a bookmark, but it applies to a whole

series instead of a single revision.

"""

import functools

from mercurial import cmdutil

from mercurial import commands

from mercurial import extensions

from mercurial import namespaces

from mercurial import obsolete

from mercurial import phases

from mercurial import util

cmdtable = {}

command = cmdutil.command(cmdtable)

def _namemap(repo, name):

    return [ctx.node() for ctx in

            repo.set('not public() and extra(topic, %s)', name)]

def _nodemap(repo, node):

    ctx = repo[node]

    t = ctx.extra().get('topic', '')

    if t and ctx.phase() > phases.public:

        return [t]

    return []

def reposetup(ui, repo):

    orig = repo.__class__

    class topicrepo(repo.__class__):

        def commitctx(self, ctx, error=None):

            current = self.currenttopic

            if current:

                ctx.extra()['topic'] = current

            return orig.commitctx(self, ctx, error=error)

        @property

        def topics(self):

            topics = set(['', self.currenttopic])

            for c in self.set('not public()'):

                topics.add(c.extra().get('topic', ''))

            topics.remove('')

            return topics

        @property

        def currenttopic(self):

            return self.vfs.tryread('topic')

    if util.safehasattr(repo, 'names'):

        repo.names.addnamespace(namespaces.namespace(

            'topics', 'topic', namemap=_namemap, nodemap=_nodemap))

    repo.__class__ = topicrepo

@command('topics', [

    ('', 'clear', False, 'clear active topic if any'),

])

def topics(ui, repo, topic=None, clear=False):

    """View current topic, set current topic, or see all topics."""

    if not obsolete.isenabled(repo, obsolete.createmarkersopt):

        raise util.Abort('current reality means you should only '

                         'use topic with obsolete enabled')

    if clear:

        if repo.vfs.exists('topic'):

            repo.vfs.unlink('topic')

        return

    if topic is not None:

        with repo.vfs.open('topic', 'w') as f:

            f.write(topic)

        return

    current = repo.currenttopic

    for t in sorted(repo.topics):

        marker = '*' if t == current else ' '

        ui.write(' %s %s\n' % (marker, t))

def updatewrap(orig, ui, repo, *args, **kwargs):

    ret = orig(ui, repo, *args, **kwargs)

    pctx = repo['.']

    if pctx.phase() == phases.public and repo.vfs.exists('topic'):

        repo.vfs.unlink('topic')

    else:

        # inherit the topic of the parent revision

        t = pctx.extra().get('topic', '')

        if t and pctx.phase() > phases.public:

            with repo.vfs.open('topic', 'w') as f:

                f.write(t)

    return ret

extensions.wrapcommand(commands.table, 'update', updatewrap)