# __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.

"""support for topic branches

Topic branches are lightweight branches which

disappear 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 context

from mercurial import extensions

from mercurial import namespaces

from mercurial import obsolete

from mercurial import phases

from mercurial import util

from . import constants

from . import revset as topicrevset

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(constants.extrakey, '')

    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()[constants.extrakey] = 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(constants.extrakey, ''))

            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 [TOPIC]', [

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

    ('', 'change', '', 'revset of existing revisions to change topic'),

])

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

    """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 change:

        if topic is None and not clear:

            raise util.Abort('changing topic requires a topic name or --clear')

        if any(not c.mutable() for c in repo.set('%r and public()', change)):

            raise util.Abort("can't change topic of a public change")

        rewrote = 0

        needevolve = False

        for c in repo.set('%r', change):

            def filectxfn(repo, ctx, path):

                try:

                    return c[path]

                except error.ManifestLookupError:

                    return None

            fixedextra = dict(c.extra())

            newtopic = None if clear else topic

            if fixedextra.get(constants.extrakey, None) == topic:

                continue

            if clear and constants.extrakey in fixedextra:

                del fixedextra[constants.extrakey]

            else:

                fixedextra[constants.extrakey] = topic

            c.parents()

            mc = context.memctx(

                repo, (c.p1().node(), c.p2().node()), c.description(),

                c.files(), filectxfn,

                user=c.user(), date=c.date(), extra=fixedextra)

            newnode = repo.commitctx(mc)

            needevolve = needevolve or (len(c.children()) > 0)

            obsolete.createmarkers(repo, [(c, (repo[newnode],))])

            rewrote += 1

        ui.status('changed topic on %d changes\n' % rewrote)

        if needevolve:

            evolvetarget = 'topic(%s)' % topic if topic else 'not topic()'

            ui.status('please run hg evolve --rev "%s" now\n' % evolvetarget)

    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(constants.extrakey, '')

        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)

topicrevset.modsetup()