# __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 (move to the public phase).

Compared to bookmark, topic is reference carried by each changesets of the

series instead of just the single head revision.  Topic are quite similar to

the way named branch work, except they eventualy fade away when the changeset

becomes part of the immutable history. Changeset can belong to both a topic and

a named branch, but as long as it is mutable, its topic identity will prevail.

As a result, default destination for 'update', 'merge', etc...  will take topic

into account. When a topic is active these operations will only consider other

changesets on that topic (and, in some occurence, bare changeset on same

branch).  When no topic is active, changeset with topic will be ignored and

only bare one on the same branch will be taken in account.

There is currently two commands to be used with that extension: 'topics' and

'stack'.

The 'hg topics' command is used to set the current topic, change and list

existing one. 'hg topics --verbose' will list various information related to

each topic.

The 'stack' will show you information about the stack of commit belonging to

your current topic.

Topic is offering you aliases reference to changeset in your current topic

stack as 't#'. For example, 't1' refers to the root of your stack, 't2' to the

second commits, etc. The 'hg stack' command show these number.

Push behavior will change a bit with topic. When pushing to a publishing

repository the changesets will turn public and the topic data on them will fade

away. The logic regarding pushing new heads will behave has before, ignore any

topic related data. When pushing to a non-publishing repository (supporting

topic), the head checking will be done taking topic data into account.

Push will complain about multiple heads on a branch if you push multiple heads

with no topic information on them (or multiple public heads). But pushing a new

topic will not requires any specific flag. However, pushing multiple heads on a

topic will be met with the usual warning.

The 'evolve' extension takes 'topic' into account. 'hg evolve --all'

will evolve all changesets in the active topic. In addition, by default. 'hg

next' and 'hg prev' will stick to the current topic.

Be aware that this extension is still an experiment, commands and other features

are likely to be change/adjusted/dropped over time as we refine the concept.

"""

from __future__ import absolute_import

import re

from mercurial.i18n import _

from mercurial import (

    branchmap,

    cmdutil,

    commands,

    context,

    error,

    extensions,

    localrepo,

    lock,

    merge,

    namespaces,

    node,

    obsolete,

    patch,

    phases,

    registrar,

    util,

)

from . import (

    constants,

    revset as topicrevset,

    destination,

    stack,

    topicmap,

    discovery,

)

if util.safehasattr(registrar, 'command'):

    commandfunc = registrar.command

else: # compat with hg < 4.3

    commandfunc = cmdutil.command

cmdtable = {}

command = commandfunc(cmdtable)

colortable = {'topic.active': 'green',

              'topic.list.troubledcount': 'red',

              'topic.list.headcount.multiple': 'yellow',

              'topic.list.behindcount': 'cyan',

              'topic.list.behinderror': 'red',

              'topic.stack.index': 'yellow',

              'topic.stack.index.base': 'none dim',

              'topic.stack.desc.base': 'none dim',

              'topic.stack.state.base': 'dim',

              'topic.stack.state.clean': 'green',

              'topic.stack.index.current': 'cyan',       # random pick

              'topic.stack.state.current': 'cyan bold',  # random pick

              'topic.stack.desc.current': 'cyan',        # random pick

              'topic.stack.state.unstable': 'red',

              'topic.stack.summary.behindcount': 'cyan',

              'topic.stack.summary.behinderror': 'red',

              'topic.stack.summary.headcount.multiple': 'yellow',

              # default color to help log output and thg

              # (first pick I could think off, update as needed

              'log.topic': 'green_background',

              'topic.active': 'green',

             }

testedwith = '4.0.2 4.1.3 4.2'

def _contexttopic(self):

    return self.extra().get(constants.extrakey, '')

context.basectx.topic = _contexttopic

topicrev = re.compile(r'^t\d+$')

def _namemap(repo, name):

    if topicrev.match(name):

        idx = int(name[1:])

        topic = repo.currenttopic

        if not topic:

            raise error.Abort(_('cannot resolve "%s": no active topic') % name)

        revs = list(stack.getstack(repo, topic))

        try:

            r = revs[idx - 1]

        except IndexError:

            msg = _('cannot resolve "%s": topic "%s" has only %d changesets')

            raise error.Abort(msg % (name, topic, len(revs)))

        return [repo[r].node()]

    if name not in repo.topics:

        return []

    return [ctx.node() for ctx in

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

def _nodemap(repo, node):

    ctx = repo[node]

    t = ctx.topic()

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

        return [t]

    return []

def uisetup(ui):

    destination.modsetup(ui)

    topicrevset.modsetup(ui)

    discovery.modsetup(ui)

    topicmap.modsetup(ui)

    setupimportexport(ui)

    extensions.afterloaded('rebase', _fixrebase)

    entry = extensions.wrapcommand(commands.table, 'commit', commitwrap)

    entry[1].append(('t', 'topic', '',

                     _("use specified topic"), _('TOPIC')))

    extensions.wrapfunction(cmdutil, 'buildcommittext', committextwrap)

    extensions.wrapfunction(merge, 'update', mergeupdatewrap)

    cmdutil.summaryhooks.add('topic', summaryhook)

def reposetup(ui, repo):

    if not isinstance(repo, localrepo.localrepository):

        return # this can be a peer in the ssh case (puzzling)

    if repo.ui.config('experimental', 'thg.displaynames', None) is None:

        repo.ui.setconfig('experimental', 'thg.displaynames', 'topics',

                          source='topic-extension')

    class topicrepo(repo.__class__):

        def _restrictcapabilities(self, caps):

            caps = super(topicrepo, self)._restrictcapabilities(caps)

            caps.add('topics')

            return caps

        def commit(self, *args, **kwargs):

            backup = self.ui.backupconfig('ui', 'allowemptycommit')

            try:

                if repo.currenttopic != repo['.'].topic():

                    # bypass the core "nothing changed" logic

                    self.ui.setconfig('ui', 'allowemptycommit', True)

                return super(topicrepo, self).commit(*args, **kwargs)

            finally:

                self.ui.restoreconfig(backup)

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

            if isinstance(ctx, context.workingcommitctx):

                current = self.currenttopic

                if current:

                    ctx.extra()[constants.extrakey] = current

            if (isinstance(ctx, context.memctx) and

                ctx.extra().get('amend_source') and

                ctx.topic() and

                not self.currenttopic):

                # we are amending and need to remove a topic

                del ctx.extra()[constants.extrakey]

            with topicmap.usetopicmap(self):

                return super(topicrepo, self).commitctx(ctx, error=error)

        @property

        def topics(self):

            if self._topics is not None:

                return self._topics

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

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

                topics.add(c.topic())

            topics.remove('')

            self._topics = topics

            return topics

        @property

        def currenttopic(self):

            return self.vfs.tryread('topic')

        def branchmap(self, topic=True):

            if not topic:

                super(topicrepo, self).branchmap()

            with topicmap.usetopicmap(self):

                branchmap.updatecache(self)

            return self._topiccaches[self.filtername]

        def destroyed(self, *args, **kwargs):

            with topicmap.usetopicmap(self):

                return super(topicrepo, self).destroyed(*args, **kwargs)

        def invalidatevolatilesets(self):

            # XXX we might be able to move this to something invalidated less often

            super(topicrepo, self).invalidatevolatilesets()

            self._topics = None

            if '_topiccaches' in vars(self.unfiltered()):

                self.unfiltered()._topiccaches.clear()

        def peer(self):

            peer = super(topicrepo, self).peer()

            if getattr(peer, '_repo', None) is not None: # localpeer

                class topicpeer(peer.__class__):

                    def branchmap(self):

                        usetopic = not self._repo.publishing()

                        return self._repo.branchmap(topic=usetopic)

                peer.__class__ = topicpeer

            return peer

    repo.__class__ = topicrepo

    repo._topics = None

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

        repo.names.addnamespace(namespaces.namespace(

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

            listnames=lambda repo: repo.topics))

@command('topics [TOPIC]', [

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

        ('r', 'rev', '', 'revset of existing revisions', _('REV')),

        ('l', 'list', False, 'show the stack of changeset in the topic'),

    ] + commands.formatteropts)

def topics(ui, repo, topic='', clear=False, rev=None, list=False, **opts):

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

    The --verbose version of this command display various information on the state of each topic."""

    if list:

        if clear or rev:

            raise error.Abort(_("cannot use --clear or --rev with --list"))

        if not topic:

            topic = repo.currenttopic

        if not topic:

            raise error.Abort(_('no active topic to list'))

        return stack.showstack(ui, repo, topic, opts)

    if rev:

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

            raise error.Abort(_('must have obsolete enabled to change topics'))

        if clear:

            topic = None

        elif not topic:

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

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

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

        _changetopics(ui, repo, rev, topic)

    if clear:

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

            repo.vfs.unlink('topic')

        return

    if topic:

        with repo.wlock():

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

                f.write(topic)

        return

    _listtopics(ui, repo, opts)

@command('stack [TOPIC]', [] + commands.formatteropts)

def cmdstack(ui, repo, topic='', **opts):

    """list all changesets in a topic and other information

    List the current topic by default."""

    if not topic:

        topic = repo.currenttopic

    if not topic:

        raise error.Abort(_('no active topic to list'))

    return stack.showstack(ui, repo, topic, opts)

def _changetopics(ui, repo, revset, newtopic):

    rewrote = 0

    needevolve = False

    try:

        p1 = None

        p2 = None

        successors = {}

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

            def filectxfn(repo, ctx, path):

                try:

                    return c[path]

                except error.ManifestLookupError:

                    return None

            fixedextra = dict(c.extra())

            ui.debug('old node id is %s\n' % node.hex(c.node()))

            ui.debug('origextra: %r\n' % fixedextra)

            oldtopic = fixedextra.get(constants.extrakey, None)

            if oldtopic == newtopic:

                continue

            if newtopic is None:

                del fixedextra[constants.extrakey]

            else:

                fixedextra[constants.extrakey] = newtopic

            if 'amend_source' in fixedextra:

                # TODO: right now the commitctx wrapper in

                # topicrepo overwrites the topic in extra if

                # amend_source is set to support 'hg commit

                # --amend'. Support for amend should be adjusted

                # to not be so invasive.

                del fixedextra['amend_source']

            ui.debug('changing topic of %s from %s to %s\n' % (

                c, oldtopic, newtopic))

            ui.debug('fixedextra: %r\n' % fixedextra)

            # While changing topic of set of linear commits, make sure that

            # we base our commits on new parent rather than old parent which

            # was obsoleted while changing the topic

            p1 = c.p1().node()

            p2 = c.p2().node()

            if p1 in successors:

                p1 = successors[p1]

            if p2 in successors:

                p2 = successors[p2]

            mc = context.memctx(

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

                c.files(), filectxfn,

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

            newnode = repo.commitctx(mc)

            successors[c.node()] = newnode

            ui.debug('new node id is %s\n' % node.hex(newnode))

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

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

            rewrote += 1

        txn.close()

    finally:

        lock.release(txn, l)

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

    if needevolve:

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

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

def _listtopics(ui, repo, opts):

    fm = ui.formatter('bookmarks', opts)

    activetopic = repo.currenttopic