# Copyright 2011 Peter Arrenbrecht <peter.arrenbrecht@gmail.com>

#                Logilab SA        <contact@logilab.fr>

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

#                Patrick Mezard <patrick@mezard.eu>

#

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

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

"""evolve templates

"""

from . import (

    exthelper,

    obshistory

)

from mercurial import (

    templatekw,

    node,

)

eh = exthelper.exthelper()

### template keywords

# XXX it does not handle troubles well :-/

@eh.templatekw('obsolete')

def obsoletekw(repo, ctx, templ, **args):

    """:obsolete: String. Whether the changeset is ``obsolete``.

    """

    if ctx.obsolete():

        return 'obsolete'

    return ''

@eh.templatekw('troubles')

def showtroubles(**args):

    """:troubles: List of strings. Evolution troubles affecting the changeset

    (zero or more of "unstable", "divergent" or "bumped")."""

    ctx = args['ctx']

    try:

        # specify plural= explicitly to trigger TypeError on hg < 4.2

        return templatekw.showlist('trouble', ctx.troubles(), args,

                                   plural='troubles')

    except TypeError:

        return templatekw.showlist('trouble', ctx.troubles(), plural='troubles',

                                   **args)

def closestprecursors(repo, nodeid):

    """ Yield the list of next precursors pointing on visible changectx nodes

    """

    precursors = repo.obsstore.precursors

    stack = [nodeid]

    while stack:

        current = stack.pop()

        currentpreccs = precursors.get(current, ())

        for prec in currentpreccs:

            precnodeid = prec[0]

            if precnodeid in repo:

                yield precnodeid

            else:

                stack.append(precnodeid)

@eh.templatekw("precursors")

    """Returns a string containing the list if the closest successors

    displayed

    """

def closestsuccessors(repo, nodeid):

    """ returns the closest visible successors sets instead.

    """

    return directsuccessorssets(repo, nodeid)

@eh.templatekw("successors")

def shownextvisiblesuccessors(repo, ctx, templ, **args):

    """Returns a string of sets of successors for a changectx in this format:

    [ctx1, ctx2], [ctx3] if ctx has been splitted into ctx1 and ctx2 while

    also diverged into ctx3"""

    if not ctx.obsolete():

        return ''

    ssets = closestsuccessors(repo, ctx.node())

    final = []

    for ss in ssets:

        final.append('[%s]' % ', '.join(map(node.short, ss)))

    return ', '.join(final)

@eh.templatekw("obsfate_quiet")

def showobsfate_quiet(repo, ctx, templ, **args):

    if not ctx.obsolete():

        return ''

    successorssets = closestsuccessors(repo, ctx.node())

    return obshistory._humanizedobsfate(*obshistory._getobsfateandsuccs(repo, ctx, successorssets))

# copy from mercurial.obsolete with a small change to stop at first known changeset.

def directsuccessorssets(repo, initialnode, cache=None):

    """return set of all direct successors of initial nodes

    """

    succmarkers = repo.obsstore.successors

    # Stack of nodes we search successors sets for

    toproceed = [initialnode]

    # set version of above list for fast loop detection

    # element added to "toproceed" must be added here

    stackedset = set(toproceed)

    if cache is None:

        cache = {}

    while toproceed:

        current = toproceed[-1]

        if current in cache:

            stackedset.remove(toproceed.pop())

        elif current != initialnode and current in repo:

            # We have a valid direct successors.

            cache[current] = [(current,)]

        elif current not in succmarkers:

            if current in repo:

                # We have a valid last successors.

                cache[current] = [(current,)]

            else:

                # Final obsolete version is unknown locally.

                # Do not count that as a valid successors

                cache[current] = []

        else:

            for mark in sorted(succmarkers[current]):

                for suc in mark[1]:

                    if suc not in cache:

                        if suc in stackedset:

                            # cycle breaking

                            cache[suc] = []

                        else:

                            # case (3) If we have not computed successors sets

                            # of one of those successors we add it to the

                            # `toproceed` stack and stop all work for this

                            # iteration.

                            toproceed.append(suc)

                            stackedset.add(suc)

                            break

                else:

                    continue

                break

            else:

                succssets = []

                for mark in sorted(succmarkers[current]):

                    # successors sets contributed by this marker

                    markss = [[]]

                    for suc in mark[1]:

                        # cardinal product with previous successors

                        productresult = []

                        for prefix in markss:

                            for suffix in cache[suc]:

                                newss = list(prefix)

                                for part in suffix:

                                    # do not duplicated entry in successors set

                                    # first entry wins.

                                    if part not in newss:

                                        newss.append(part)

                                productresult.append(newss)

                        markss = productresult

                    succssets.extend(markss)

                # remove duplicated and subset

                seen = []

                final = []

                candidate = sorted(((set(s), s) for s in succssets if s),

                                   key=lambda x: len(x[1]), reverse=True)

                for setversion, listversion in candidate:

                    for seenset in seen:

                        if setversion.issubset(seenset):

                            break

                    else:

                        final.append(listversion)

                        seen.append(setversion)

                final.reverse() # put small successors set first

                cache[current] = final

    return cache[initialnode]