# 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.

'''Extends Mercurial feature related to Changeset Evolution

This extension provides several commands to mutate history and deal with

issues it may raise.

It also:

    - enables the "Changeset Obsolescence" feature of mercurial,

    - alters core commands and extensions that rewrite history to use

      this feature,

    - improves some aspect of the early implementation in 2.3

'''

buglink = 'https://bitbucket.org/marmoute/mutable-history/issues'

import random

from mercurial import util

try:

    from mercurial import obsolete

    if not obsolete._enabled:

        obsolete._enabled = True

    from mercurial import bookmarks

    bookmarks.bmstore

except (ImportError, AttributeError):

from mercurial import bookmarks

from mercurial import cmdutil

from mercurial import commands

from mercurial import context

from mercurial import copies

from mercurial import discovery

from mercurial import error

from mercurial import extensions

from mercurial import hg

from mercurial import localrepo

from mercurial import lock as lockmod

from mercurial import merge

from mercurial import node

from mercurial import phases

from mercurial import revset

from mercurial import scmutil

from mercurial import templatekw

from mercurial.i18n import _

from mercurial.commands import walkopts, commitopts, commitopts2

from mercurial.node import nullid

import mercurial.hgweb.hgweb_mod

# This extension contains the following code

#

# - Extension Helper code

# - Obsolescence cache

# - ...

# - Older format compat

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

### Extension helper                                              ###

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

class exthelper(object):

    """Helper for modular extension setup

    A single helper should be instanciated for each extension. Helper

    methods are then used as decorator for various purpose.

    All decorators return the original function and may be chained.

    """

    def __init__(self):

        self._uicallables = []

        self._extcallables = []

        self._repocallables = []

        self._revsetsymbols = []

        self._templatekws = []

        self._commandwrappers = []

        self._extcommandwrappers = []

        self._functionwrappers = []

        self._duckpunchers = []

    def final_uisetup(self, ui):

        """Method to be used as the extension uisetup

        The following operations belong here:

        - Changes to ui.__class__ . The ui object that will be used to run the

          command has not yet been created. Changes made here will affect ui

          objects created after this, and in particular the ui that will be

          passed to runcommand

        - Command wraps (extensions.wrapcommand)

        - Changes that need to be visible to other extensions: because

          initialization occurs in phases (all extensions run uisetup, then all

          run extsetup), a change made here will be visible to other extensions

          during extsetup

        - Monkeypatch or wrap function (extensions.wrapfunction) of dispatch

          module members

        - Setup of pre-* and post-* hooks

        - pushkey setup

        """

        for cont, funcname, func in self._duckpunchers:

            setattr(cont, funcname, func)

        for command, wrapper in self._commandwrappers:

            extensions.wrapcommand(commands.table, command, wrapper)

        for cont, funcname, wrapper in self._functionwrappers:

            extensions.wrapfunction(cont, funcname, wrapper)

        for c in self._uicallables:

            c(ui)

    def final_extsetup(self, ui):

        """Method to be used as a the extension extsetup

        The following operations belong here:

        - Changes depending on the status of other extensions. (if

          extensions.find('mq'))

        - Add a global option to all commands

        - Register revset functions

        """

        knownexts = {}

        for name, symbol in self._revsetsymbols:

            revset.symbols[name] = symbol

        for name, kw in self._templatekws:

            templatekw.keywords[name] = kw

        for ext, command, wrapper in self._extcommandwrappers:

            if ext not in knownexts:

                e = extensions.find(ext)

                if e is None:

                    raise util.Abort('extension %s not found' % ext)

                knownexts[ext] = e.cmdtable

            extensions.wrapcommand(knownexts[ext], commands, wrapper)

        for c in self._extcallables:

            c(ui)

    def final_reposetup(self, ui, repo):

        """Method to be used as a the extension reposetup

        The following operations belong here:

        - All hooks but pre-* and post-*

        - Modify configuration variables

        - Changes to repo.__class__, repo.dirstate.__class__

        """

        for c in self._repocallables:

            c(ui, repo)

    def uisetup(self, call):

        """Decorated function will be executed during uisetup

        example::

            @eh.uisetup

            def setupbabar(ui):

                print 'this is uisetup!'

        """

        self._uicallables.append(call)

        return call

    def extsetup(self, call):

        """Decorated function will be executed during extsetup

        example::

            @eh.extsetup

            def setupcelestine(ui):

                print 'this is extsetup!'

        """

        self._uicallables.append(call)

        return call

    def reposetup(self, call):

        """Decorated function will be executed during reposetup

        example::

            @eh.reposetup

            def setupzephir(ui, repo):

                print 'this is reposetup!'

        """

        self._repocallables.append(call)

        return call

    def revset(self, symbolname):

        """Decorated function is a revset symbol

        The name of the symbol must be given as the decorator argument.

        The symbol is added during `extsetup`.

        example::

            @eh.revset('hidden')

            def revsetbabar(repo, subset, x):

                args = revset.getargs(x, 0, 0, 'babar accept no argument')

                return [r for r in subset if 'babar' in repo[r].description()]

        """

        def dec(symbol):

            self._revsetsymbols.append((symbolname, symbol))

            return symbol

        return dec

    def templatekw(self, keywordname):

        """Decorated function is a revset keyword

        The name of the keyword must be given as the decorator argument.

        The symbol is added during `extsetup`.

        example::

            @eh.templatekw('babar')

            def kwbabar(ctx):

                return 'babar'

        """

        def dec(keyword):

            self._templatekws.append((keywordname, keyword))

            return keyword

        return dec

    def wrapcommand(self, command, extension=None):

        """Decorated function is a command wrapper

        The name of the command must be given as the decorator argument.

        The wrapping is installed during `uisetup`.

        If the second option `extension` argument is provided, the wrapping

        will be applied in the extension commandtable. This argument must be a

        string that will be searched using `extension.find` if not found and

        Abort error is raised. If the wrapping applies to an extension, it is

        installed during `extsetup`

        example::

            @eh.wrapcommand('summary')

            def wrapsummary(orig, ui, repo, *args, **kwargs):

                ui.note('Barry!')

                return orig(ui, repo, *args, **kwargs)

        """

        def dec(wrapper):

            if extension is None:

                self._commandwrappers.append((command, wrapper))

            else:

                self._extcommandwrappers.append((extension, command, wrapper))

            return wrapper

        return dec

    def wrapfunction(self, container, funcname):

        """Decorated function is a function wrapper

        This function takes two arguments, the container and the name of the

        function to wrap. The wrapping is performed during `uisetup`.

        (there is no extension support)

        example::

            @eh.function(discovery, 'checkheads')

            def wrapfunction(orig, *args, **kwargs):

                ui.note('His head smashed in and his heart cut out')

                return orig(*args, **kwargs)

        """

        def dec(wrapper):

            self._functionwrappers.append((container, funcname, wrapper))

            return wrapper

        return dec

    def addattr(self, container, funcname):

        """Decorated function is to be added to the container

        This function takes two arguments, the container and the name of the

        function to wrap. The wrapping is performed during `uisetup`.

        example::

            @eh.function(context.changectx, 'babar')

            def babar(ctx):

                return 'babar' in ctx.description

        """

        def dec(func):

            self._duckpunchers.append((container, funcname, func))

            return func

        return dec

eh = exthelper()

uisetup = eh.final_uisetup

extsetup = eh.final_extsetup

reposetup = eh.final_reposetup

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

### Critical fix                                                  ###

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

@eh.wrapfunction(mercurial.obsolete, '_readmarkers')

def safereadmarkers(orig, data):

    """safe maker wrapper to remove nullid succesors

    Nullid successors was created by older version of evolve.

    """

    for marker in orig(data):

        if nullid in marker[1]:

            marker = (marker[0],

                      tuple(s for s in marker[1] if s != nullid),

                      marker[2],

                      marker[3])

        yield marker

cachefuncs = obsolete.cachefuncs

cachefor = obsolete.cachefor

getrevs = obsolete.getrevs

clearobscaches = obsolete.clearobscaches

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

### Complete troubles computation logic                           ###

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

# there is one kind of trouble not handled by core right now:

# - divergent: (two changeset try to succeed to the same precursors)

#

# This section add support for those two addition trouble

#

# - Cache computation

# - revset and ctx method

# - push warning

### Cache computation

latediff = 1  # flag to prevent taking late comer fix into account

@cachefor('divergent')

def _computedivergentset(repo):

    """the set of rev trying to obsolete public revision"""

    divergent = set()

    obsstore = repo.obsstore

    newermap = {}

    for ctx in repo.set('(not public()) - obsolete()'):

        mark = obsstore.precursors.get(ctx.node(), ())

        toprocess = set(mark)

        while toprocess:

            prec = toprocess.pop()[0]

            if prec not in newermap:

                successorssets(repo, prec, newermap)

            newer = [n for n in newermap[prec] if n]

            if len(newer) > 1:

                divergent.add(ctx.rev())

                break

            toprocess.update(obsstore.precursors.get(prec, ()))

    return divergent

### changectx method

@eh.addattr(context.changectx, 'latecomer')

def latecomer(ctx):

    """is the changeset bumped (Try to succeed to public change)"""

    return ctx.bumped()

@eh.addattr(context.changectx, 'conflicting')

@eh.addattr(context.changectx, 'divergent')

def divergent(ctx):

    """is the changeset divergent (Try to succeed to public change)"""

    if ctx.node() is None:

        return False

    return ctx.rev() in getrevs(ctx._repo, 'divergent')

### revset symbol

eh.revset('latecomer')(revset.symbols['bumped'])

@eh.revset('conflicting')

@eh.revset('divergent')

def revsetdivergent(repo, subset, x):

    """``divergent()``

    Changesets marked as successors of a same changeset.

    """

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

    conf = getrevs(repo, 'divergent')

    return [r for r in subset if r in conf]

### Discovery wrapping

@eh.wrapfunction(discovery, 'checkheads')

def wrapcheckheads(orig, repo, remote, outgoing, *args, **kwargs):

    """wrap mercurial.discovery.checkheads

    * prevent divergent to be pushed

    """

    # do not push instability

    for h in outgoing.missingheads:

        # Checking heads is enough, obsolete descendants are either

        # obsolete or unstable.

        ctx = repo[h]

        if ctx.divergent():

            raise util.Abort(_("push includes a divergent changeset: %s!")

                             % ctx)

    return orig(repo, remote, outgoing, *args, **kwargs)