import weakref

from mercurial.i18n import _

from . import topicmap

def _headssummary(orig, repo, remote, outgoing):

    publishing = ('phases' not in remote.listkeys('namespaces')

                  or bool(remote.listkeys('phases').get('publishing', False)))

    if publishing or not remote.capable('topics'):

        return orig(repo, remote, outgoing)

    oldrepo = repo.__class__

    oldbranchcache = branchmap.branchcache

    oldfilename = branchmap._filename

    try:

        class repocls(repo.__class__):

            def __getitem__(self, key):

                ctx = super(repocls, self).__getitem__(key)

                oldbranch = ctx.branch

                def branch():

                    branch = oldbranch()

                    topic = ctx.topic()

                    if topic:

                        branch = "%s:%s" % (branch, topic)

                    return branch

                ctx.branch = branch

                return ctx

        repo.__class__ = repocls

        branchmap.branchcache = topicmap.topiccache

        branchmap._filename = topicmap._filename

        summary = orig(repo, remote, outgoing)

        for key, value in summary.iteritems():

            if ':' in key: # This is a topic

                if value[0] is None and value[1]:

                    summary[key] = ([value[1].pop(0)], ) + value[1:]

        return summary

    finally:

        repo.__class__ = oldrepo

        branchmap.branchcache = oldbranchcache

        branchmap._filename = oldfilename

def wireprotobranchmap(orig, repo, proto):

    oldrepo = repo.__class__

    try:

        class repocls(repo.__class__):

            def branchmap(self):

                usetopic = not self.publishing()

                return super(repocls, self).branchmap(topic=usetopic)

        repo.__class__ = repocls

        return orig(repo, proto)

    finally:

        repo.__class__ = oldrepo

# Discovery have deficiency around phases, branch can get new heads with pure

# phases change. This happened with a changeset was allowed to be pushed

# because it had a topic, but it later become public and create a new branch

# head.

#

# Handle this by doing an extra check for new head creation server side

def _nbheads(repo):

    data = {}

    for b in repo.branchmap().iterbranches():

        if ':' in b[0]:

            continue

        data[b[0]] = len(b[1])

    return data

def handlecheckheads(orig, op, inpart):

    orig(op, inpart)

    if op.repo.publishing():

        return

    tr = op.gettransaction()

    if tr.hookargs['source'] not in ('push', 'serve'): # not a push

        return

    tr._prepushheads = _nbheads(op.repo)

    reporef = weakref.ref(op.repo)

    oldvalidator = tr.validator

    def validator(tr):

        repo = reporef()

        if repo is not None:

            repo.invalidatecaches()

            finalheads = _nbheads(repo)

            for branch, oldnb in tr._prepushheads.iteritems():

                newnb = finalheads.pop(branch, 0)

                if oldnb < newnb:

                    msg = _('push create a new head on branch "%s"' % branch)

                    raise error.Abort(msg)

            for branch, newnb in finalheads.iteritems():

                if 1 < newnb:

                    msg = _('push create more than 1 head on new branch "%s"'

                            % branch)

                    raise error.Abort(msg)

        return oldvalidator(tr)

    tr.validator = validator

handlecheckheads.params = frozenset()

def _pushb2phases(orig, pushop, bundler):

    hascheck = any(p.type == 'check:heads' for p in bundler._parts)

    if pushop.outdatedphases and not hascheck:

        exchange._pushb2ctxcheckheads(pushop, bundler)

    return orig(pushop, bundler)

def wireprotocaps(orig, repo, proto):

    caps = orig(repo, proto)

    if repo.peer().capable('topics'):

        caps.append('topics')

    return caps