import weakref
from mercurial import branchmap
from mercurial import error
from mercurial import exchange
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)
    oldgetitem = repo.__getitem__
    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