# states.py - introduce the state concept for mercurial changeset

#

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

#                Logilab SA        <contact@logilab.fr>

#                Augie Fackler     <durin42@gmail.com>

#

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

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

'''introduce the state concept for mercurial changeset

Change can be in the following state:

0 immutable

1 mutable

2 private

name are not fixed yet.

'''

from functools import partial

from mercurial.i18n import _

from mercurial import cmdutil

from mercurial import scmutil

from mercurial import context

from mercurial import revset

from mercurial import templatekw

from mercurial import util

from mercurial import node

from mercurial.node import nullid, hex, short

from mercurial import discovery

from mercurial import extensions

from mercurial import wireproto

_NOSHARE=2

_MUTABLE=1

class state(object):

    def __init__(self, name, order=0, next=None):

        self.name = name

        self.order = order

        assert next is None or self < next

        self.next = next

    def __repr__(self):

        return 'state(%s)' % self.name

    def __str__(self):

        return self.name

    @util.propertycache

    def trackheads(self):

        """Do we need to track heads of changeset in this state ?

        We don't need to track heads for the last state as this is repos heads"""

        return self.next is not None

    def __cmp__(self, other):

        return cmp(self.order, other.order)

    @util.propertycache

    def _revsetheads(self):

        """function to be used by revset to finds heads of this states"""

        assert self.trackheads

        def revsetheads(repo, subset, x):

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

            heads = map(repo.changelog.rev, repo._statesheads[self])

            heads.sort()

            return heads

        return revsetheads

    @util.propertycache

    def headssymbol(self):

        """name of the revset symbols"""

        if self.trackheads:

            return "%sheads" % self.name

        else:

            return 'heads'

ST2 = state('draft', _NOSHARE | _MUTABLE)

ST1 = state('ready', _MUTABLE, next=ST2)

ST0 = state('published', next=ST1)

STATES = (ST0, ST1, ST2)

# util function

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

def noderange(repo, revsets):

    return map(repo.changelog.node,

               scmutil.revrange(repo, revsets))

# Patch changectx

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

def state(ctx):

    return ctx._repo.nodestate(ctx.node())

context.changectx.state = state

# improve template

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

def showstate(ctx, **args):

    return ctx.state()

# New revset predicate

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

# New commands

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

def cmdsetstate(ui, repo, statename, *changesets):

    """change changeset state"""

    for state in STATES: # few states

        if state.name == statename:

            break

    else:

        raise util.Abort(_('unknown state: %s') % statename)

    revs = scmutil.revrange(repo, changesets)

    repo.setstate(state, [repo.changelog.node(rev) for rev in revs])

    return 0

cmdtable = {

    'setstate':  (cmdsetstate,   [], _('<state> <revset>')),

    }

templatekw.keywords['state'] = showstate

def uisetup(ui):

    def filterprivateout(orig, repo, *args,**kwargs):

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

        return common, repo._reducehead(heads)

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

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

        heads = remote._reducehead(heads)

        return common, anyinc, heads

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

    extensions.wrapfunction(discovery, 'findcommonincoming', filterprivatein)

    # Write protocols

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

    def heads(repo, proto):

        h = repo.stateheads(ST1)

        return wireproto.encodelist(h) + "\n"

    def _reducehead(wirerepo, heads):

        """heads filtering is done repo side"""

        return heads

    wireproto.wirerepository._reducehead = _reducehead

    wireproto.commands['heads'] = (heads, '')

def reposetup(ui, repo):

    if not repo.local():

        return

    o_cancopy =repo.cancopy

    class statefulrepo(repo.__class__):

        def nodestate(self, node):

            rev = self.changelog.rev(node)

            for state in STATES[::-1]:

                # XXX avoid for untracked heads

                if state.next is not None:

                    for head in self.stateheads(state):

                        revhead = self.changelog.rev(head)

                        if self.changelog.descendant(revhead, rev):

                            return state.next

            return state

        def stateheads(self, state):

            if state.trackheads:

                if self.ui.configbool('states', state.next.name, False):

                    return self._statesheads[state]

            return self.heads()

        @util.propertycache

        def _statesheads(self):

            return self._readstatesheads()

        def _readheadsfile(self, filename):

            heads = [nullid]

            try:

                f = self.opener(filename)

                try:

                    heads = sorted([node.bin(n) for n in f.read().split() if n])

                finally:

                    f.close()

            except IOError:

                pass

            return heads

        def _readstatesheads(self):

            statesheads = {}

            for state in STATES:

                if state.trackheads:

                    filename = 'states/%s-heads' % state.name

                    statesheads[state] = self._readheadsfile(filename)

            return statesheads

        def _writeheadsfile(self, filename, heads):

            f = self.opener(filename, 'w', atomictemp=True)

            try:

                for h in heads:

                    f.write(hex(h) + '\n')

                f.rename()

            finally:

                f.close()

        def _writestateshead(self):

            # transaction!

            for state in STATES:

                if state.trackheads:

                    filename = 'states/%s-heads' % state.name

                    self._writeheadsfile(filename, self._statesheads[state])

        def setstate(self, state, nodes):

            """freeze targets changeset and it's ancestors.

            Simplify the list of head."""

            heads = self._statesheads[state]

            olds = heads[:]

            heads.extend(nodes)

            heads[:] = set(heads)

            heads.sort()

            if olds != heads:

                heads[:] = noderange(repo, ["heads(::%s())" % state.headssymbol])

                heads.sort()

            if olds != heads:

                self._writestateshead()

            if state.next is not None and state.next.trackheads:

                self.setstate(state.next, nodes) # cascading

        def _reducehead(self, candidates):

            selected = set()

            for candidate in candidates:

                rev = self.changelog.rev(candidate)

                ok = True

                for h in self.stateheads(ST1):

                    revh = self.changelog.rev(h)

                    if self.changelog.descendant(revh, rev):

                        ok = False

                        selected.add(h)

                if ok:

                    selected.add(candidate)

            return sorted(selected)

        def cancopy(self):

            return o_cancopy() and (self.stateheads(ST1) == self.heads())

    repo.__class__ = statefulrepo