# Copyright 2017 Octobus <contact@octobus.net>

#

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

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

"""

Compatibility module

"""

from mercurial import (

    hg,

    obsolete,

    util,

)

try:

    from mercurial import obsutil

    obsutil.closestpredecessors

except ImportError:

    obsutil = None

from . import (

    exthelper,

)

eh = exthelper.exthelper()

if not util.safehasattr(hg, '_copycache'):

    # exact copy of relevantmarkers as in Mercurial-176d1a0ce385

    # this fixes relevant markers computation for version < hg-4.3

    @eh.wrapfunction(obsolete.obsstore, 'relevantmarkers')

    def relevantmarkers(orig, self, nodes):

        """return a set of all obsolescence markers relevant to a set of nodes.

        "relevant" to a set of nodes mean:

        - marker that use this changeset as successor

        - prune marker of direct children on this changeset

        - recursive application of the two rules on precursors of these markers

        It is a set so you cannot rely on order.

        Backport of mercurial changeset 176d1a0ce385 for version < 4.3

        """

        pendingnodes = set(nodes)

        seenmarkers = set()

        seennodes = set(pendingnodes)

        precursorsmarkers = self.precursors

        succsmarkers = self.successors

        children = self.children

        while pendingnodes:

            direct = set()

            for current in pendingnodes:

                direct.update(precursorsmarkers.get(current, ()))

                pruned = [m for m in children.get(current, ()) if not m[1]]

                direct.update(pruned)

                pruned = [m for m in succsmarkers.get(current, ()) if not m[1]]

                direct.update(pruned)

            direct -= seenmarkers

            pendingnodes = set([m[0] for m in direct])

            seenmarkers |= direct

            pendingnodes -= seennodes

            seennodes |= pendingnodes

        return seenmarkers

# successors set move from mercurial.obsolete to mercurial.obsutil in 4.3

def successorssets(*args, **kwargs):

    func = getattr(obsutil, 'successorssets', None)

    if func is None:

        func = obsolete.successorssets

    return func(*args, **kwargs)

# allprecursors set move from mercurial.obsolete to mercurial.obsutil in 4.3

def allprecursors(*args, **kwargs):

    func = getattr(obsutil, 'allprecursors', None)

    if func is None:

        func = obsolete.allprecursors

    return func(*args, **kwargs)