# obsolete.py - introduce the obsolete concept in mercurial.

#

# Copyright 2011 Pierre-Yves David <pierre-yves.david@ens-lyon.org>

#                Logilab SA        <contact@logilab.fr>

#

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

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

from mercurial import util

from mercurial import context

from mercurial import revset

from mercurial import scmutil

from mercurial import extensions

from mercurial import pushkey

from mercurial import discovery

from mercurial import error

from mercurial.node import hex, bin

# Patch changectx

#############################

def obsolete(ctx):

    """is the changeset obsolete by other"""

    if ctx.node()is None:

        return False

    return bool(ctx._repo.obsoletedby(ctx.node()))

context.changectx.obsolete = obsolete

ohidden = context.changectx.hidden

def hidden(ctx):

    # hack to fill hiddenrevs

    # compute hidden (XXX should move elsewhere)

    if not getattr(ctx._repo.changelog, 'hiddeninit', False):

        basicquery = 'obsolete() - (ancestors(not obsolete() or . or bookmark()))'

        for rev in scmutil.revrange(ctx._repo, [basicquery]):

            ctx._repo.changelog.hiddenrevs.add(rev)

        ctx._repo.changelog.hiddeninit = True

    return ohidden(ctx)

context.changectx.hidden = hidden

# revset

#############################

def revsetobsolete(repo, subset, x):

    args = revset.getargs(x, 0, 0, 'publicheads takes no arguments')

    return [r for r in subset if repo[r].obsolete()] # XXX slow

def extsetup(ui):

    revset.symbols["obsolete"] = revsetobsolete

    def filterobsoleteout(orig, repo, remote, *args,**kwargs):

        common, heads = orig(repo, remote, *args, **kwargs)

        # filter obsolete

        heads = set(map(repo.changelog.rev, heads))

        obsoletes = set()

        for obj in repo._obsobjrels:

            try:

                obsoletes.add(repo.changelog.rev(obj))

            except error.LookupError:

                pass # we don't have this node locally

        outgoing = set(repo.changelog.ancestors(*heads))

        outgoing.update(heads)

        selected = outgoing - obsoletes

        heads = sorted(map(repo.changelog.node, selected))

        return common, heads

    extensions.wrapfunction(discovery, 'findcommonoutgoing', filterobsoleteout)

    try:

        rebase = extensions.find('rebase')

        if rebase:

            extensions.wrapfunction(rebase, 'concludenode', concludenode)

    except KeyError:

        pass # rebase not found

# Pushkey mechanism for mutable

#########################################

def pushobsolete(repo, key, old, relations):

    assert key == "relations"

    w = repo.wlock()

    try:

        for sub, objs in relations.iteritems():

            for obj in objs:

                repo.addobsolete(sub, obj)

    finally:

        w.release()

def listobsolete(repo):

    return {'relations': repo._obssubrels}

pushkey.register('obsolete', pushobsolete, listobsolete)

# New commands

#############################

def cmddebugobsolete(ui, repo, subject, object):

    """Add an obsolete relation between a too node

    The subject is expected to be a newer version of the object"""

    sub = repo[subject]

    obj = repo[object]

    repo.addobsolete(sub.node(), obj.node())

    return 0

cmdtable = {'debugobsolete': (cmddebugobsolete, [], '<subject> <object>')}

def reposetup(ui, repo):

    if not repo.local():

        return

    opull = repo.pull

    opush = repo.push

    class obsoletingrepo(repo.__class__):

        ### Hidden revision support

        @util.propertycache

        def hiddenrevs(self):

            # It's a property because It simpler that to handle the __init__

            revs = set()

            return revs

        ### obsolete storage

        @util.propertycache

        def _obsobjrels(self):

            """{<old-node> -> set(<new-node>)}

            also compute hidden revision"""

            #reverse sub -> objs mapping

            objrels = {}

            for sub, objs in self._obssubrels.iteritems():

                for obj in objs:

                    objrels.setdefault(obj, set()).add(sub)

            return objrels

        @util.propertycache

        def _obssubrels(self):

            """{<new-node> -> set(<old-node>)}"""

            return self._readobsrels()

        ### Disk IO

        def _readobsrels(self):

            """Write obsolete relation on disk"""

            # XXX handle lock

            rels = {}

            try:

                f = self.opener('obsolete-relations')

                try:

                    for line in f:

                        subhex, objhex = line.split()

                        rels.setdefault(bin(subhex), set()).add(bin(objhex))

                finally:

                    f.close()

            except IOError:

                pass

            return rels

        def _writeobsrels(self):

            """Write obsolete relation on disk"""

            # XXX handle lock

            f = self.opener('obsolete-relations', 'w', atomictemp=True)

            try:

                for sub, objs in self._obssubrels.iteritems():

                    for obj in objs:

                        f.write('%s %s\n' % (hex(sub), hex(obj)))

                f.rename()

            finally:

                f.close()

        ### local clone support

        def cancopy(self):

            return not bool(self._obsobjrels) # you can't copy if there is obsolete

        ### pull // push support

        def pull(self, remote, *args, **kwargs):

            obskey = remote.listkeys('obsolete')

            obsrels = obskey.get('relations', {})

            result = opull(remote, *args, **kwargs)

            for sub, objs in obsrels.iteritems():

                for obj in objs:

                    self.addobsolete(sub, obj)

            return result

        def push(self, remote, *args, **opts):

            obskey = remote.listkeys('obsolete')

            obssupport = 'relations' in obskey

            result = opush(remote, *args, **opts)

            if obssupport:

                remote.pushkey('obsolete', 'relations', {}, self._obssubrels)

            return result

        ### Public method

        def obsoletedby(self, node):

            """return the set of node that make <node> obsolete (obj)"""

            return self._obsobjrels.get(node, set())

        def obsolete(self, node):

            """return the set of node that <node> make obsolete (sub)"""

            return self._obssubrels.get(node, set())

        def addobsolete(self, sub, obj):

            """Add a relation marking that node <sub> is a new version of <obj>"""

            self._obssubrels.setdefault(sub, set()).add(obj)

            self._obsobjrels.setdefault(obj, set()).add(sub)

            try:

                self.changelog.hiddenrevs.add(repo[obj].rev())

            except error.RepoLookupError:

                pass #unknow revision (but keep propagating the data

            self._writeobsrels()

    repo.__class__ = obsoletingrepo

### Other Extension compat

############################

def concludenode(orig, repo, rev, *args, **kwargs):

    newrev = orig(repo, rev, *args, **kwargs)

    oldnode = repo[rev].node()

    newnode = repo[newrev].node()

    repo.addobsolete(newnode, oldnode)

    return newrev