"""reduce the changesets evolution feature scope for early and noob friendly ui

the full scale changeset evolution have some massive bleeding edge and it is

very easy for people not very intimate with the concept to end up in intricate

situation. in order to get some of the benefit sooner, this extension is

disabling some of the less polished aspect of evolution. it should gradually

get thinner and thinner as changeset evolution will get more polished. this

extension is only recommended for large scale organisations. individual user

should probably stick on using evolution in its current state, understand its

concept and provide feedback

This extension provides the ability to "inhibit" obsolescence markers. obsolete 

revision can be cheaply brought back to life that way. 

However as the inhibitor are not fitting in an append only model, this is 

incompatible with sharing mutable history.

"""

from mercurial import localrepo

from mercurial import obsolete

from mercurial import extensions

from mercurial import cmdutil

from mercurial import error

from mercurial import scmutil

from mercurial import commands

from mercurial import lock as lockmod

from mercurial import bookmarks

from mercurial.i18n import _

cmdtable = {}

command = cmdutil.command(cmdtable)

def reposetup(ui, repo):

    class obsinhibitedrepo(repo.__class__):

        @localrepo.storecache('obsinhibit')

        def _obsinhibit(self):

            # XXX we should make sure it is invalidated by transaction failure

            obsinhibit = set()

            raw = self.sopener.tryread('obsinhibit')

            for i in xrange(0, len(raw), 20):

                obsinhibit.add(raw[i:i+20])

            return obsinhibit

        def commit(self, *args, **kwargs):

            newnode = super(obsinhibitedrepo, self).commit(*args, **kwargs)

            if newnode is not None:

                _inhibitmarkers(repo, [newnode])

            return newnode

    repo.__class__ = obsinhibitedrepo

    # Wrapping this to inhibit obsolete revs resulting from a transaction

    extensions.wrapfunction(localrepo.localrepository,

                            'transaction', transactioncallback)

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

    """

    When moving to a commit we want to inhibit any obsolete commit affecting

    the changeset we are updating to. In other words we don't want any visible

    commit to be obsolete.

    """

    wlock = None

    try:

        # Evolve is running a hook on lock release to display a warning message 

        # if the workind dir's parent is obsolete.

        # We take the lock here to make sure that we inhibit the parent before

        # that hook get a chance to run.

        wlock = repo.wlock()

        res = orig(ui, repo, *args, **kwargs)

        newhead = repo['.'].node()

        _inhibitmarkers(repo, [newhead])

        return res

    finally:

        lockmod.release(wlock)

def _bookmarkchanged(orig, bkmstoreinst, *args, **kwargs):

    """ Add inhibition markers to every obsolete bookmarks """

    repo = bkmstoreinst._repo

    bkmstorenodes = [repo[v].node() for v in bkmstoreinst.values()]

    _inhibitmarkers(repo, bkmstorenodes)

    return orig(bkmstoreinst, *args, **kwargs)

def _bookmark(orig, ui, repo, *bookmarks, **opts):

    """ Add a -D option to the bookmark command, map it to prune -B """

    haspruneopt = opts.get('prune', False)

    if not haspruneopt:

        return orig(ui, repo, *bookmarks, **opts)

    # Call prune -B

    evolve = extensions.find('evolve')

    optsdict = {

        'new': [],

        'succ': [],

        'rev': [],

        'bookmark': bookmarks[0],

        'keep': None,

        'biject': False,

    }

    evolve.cmdprune(ui, repo, **optsdict)

# obsolescence inhibitor

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

def _schedulewrite(tr, obsinhibit):

    """Make sure on disk content will be updated on transaction commit"""

    def writer(fp):

        """Serialize the inhibited list to disk.

        """

        raw = ''.join(obsinhibit)

        fp.write(raw)

    tr.addfilegenerator('obsinhibit', ('obsinhibit',), writer)

    tr.hookargs['obs_inbihited'] = '1'

def _filterpublic(repo, nodes):

    """filter out inhibitor on public changeset

    Public changesets are already immune to obsolescence"""

    getrev = repo.changelog.nodemap.get

    getphase = repo._phasecache.phase

    return (n for n in repo._obsinhibit

            if getrev(n) is not None and getphase(repo, getrev(n)))

def _inhibitmarkers(repo, nodes):

    """add marker inhibitor for all obsolete revision under <nodes>

    Content of <nodes> and all mutable ancestors are considered. Marker for

    obsolete revision only are created.

    """

    newinhibit = repo.set('::%ln and obsolete()', nodes)

    if newinhibit:

        lock = tr = None

        try:

            lock = repo.lock()

            tr = repo.transaction('obsinhibit')

            repo._obsinhibit.update(c.node() for c in newinhibit)

            _schedulewrite(tr, _filterpublic(repo, repo._obsinhibit))

            repo.invalidatevolatilesets()

            tr.close()

        finally:

            lockmod.release(tr, lock)

def _deinhibitmarkers(repo, nodes):

    """lift obsolescence inhibition on a set of nodes

    This will be triggered when inhibited nodes received new obsolescence

    markers. Otherwise the new obsolescence markers would also be inhibited.

    """

    deinhibited = repo._obsinhibit & set(nodes)

    if deinhibited:

        tr = repo.transaction('obsinhibit')

        try:

            repo._obsinhibit -= deinhibited

            _schedulewrite(tr, _filterpublic(repo, repo._obsinhibit))

            repo.invalidatevolatilesets()

            tr.close()

        finally:

            tr.release()

def _createmarkers(orig, repo, relations, flag=0, date=None, metadata=None):

    """wrap markers create to make sure we de-inhibit target nodes"""

    # wrapping transactio to unify the one in each function

    tr = repo.transaction('add-obsolescence-marker')

    try:

        orig(repo, relations, flag, date, metadata)

        precs = (r[0].node() for r in relations)

        _deinhibitmarkers(repo, precs)

        tr.close()

    finally:

        tr.release()

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

    """ Wrap localrepo.transaction to inhibit new obsolete changes """

    def inhibitposttransaction(transaction):

        # At the end of the transaction we catch all the new visible and

        # obsolete commit to inhibit them

        ignoreset = set(getattr(repo, '_rebaseset', []))

        visibleobsolete = list(r for r in visibleobsolete if r not in ignoreset)

        if visibleobsolete:

            _inhibitmarkers(repo, [repo[r].node() for r in visibleobsolete])

    transaction = orig(repo, *args, **kwargs)

    transaction.addpostclose('inhibitposttransaction', inhibitposttransaction)

    return transaction

def extsetup(ui):

    # lets wrap the computation of the obsolete set

    # We apply inhibition there

    obsfunc = obsolete.cachefuncs['obsolete']

    def _computeobsoleteset(repo):

        """remove any inhibited nodes from the obsolete set

        This will trickle down to other part of mercurial (hidden, log, etc)"""

        obs = obsfunc(repo)

        getrev = repo.changelog.nodemap.get

        for n in repo._obsinhibit:

            obs.discard(getrev(n))

        return obs

    try:

        extensions.find('directaccess')

    except KeyError:

        errormsg = _('Cannot use inhibit without the direct access extension')

        raise error.Abort(errormsg)

    obsolete.cachefuncs['obsolete'] = _computeobsoleteset

    # wrap create marker to make it able to lift the inhibition

    extensions.wrapfunction(obsolete, 'createmarkers', _createmarkers)

    # drop divergence computation since it is incompatible with "light revive"

    obsolete.cachefuncs['divergent'] = lambda repo: set()

    # drop bumped computation since it is incompatible with "light revive"

    obsolete.cachefuncs['bumped'] = lambda repo: set()

    # wrap update to make sure that no obsolete commit is visible after an

    # update

    extensions.wrapcommand(commands.table, 'update', _update)

    # There are two ways to save bookmark changes during a transation, we

    # wrap both to add inhibition markers.

    extensions.wrapfunction(bookmarks.bmstore, 'recordchange', _bookmarkchanged)

    extensions.wrapfunction(bookmarks.bmstore, 'write', _bookmarkchanged)

    # Add bookmark -D option

    entry = extensions.wrapcommand(commands.table, 'bookmark', _bookmark)

    entry[1].append(('D','prune',None,

                    _('delete the bookmark and prune the commits underneath')))

@command('debugobsinhibit', [], '')

def cmddebugobsinhibit(ui, repo, *revs):

    """inhibit obsolescence markers effect on a set of revs"""

    nodes = (repo[r].node() for r in scmutil.revrange(repo, revs))

    _inhibitmarkers(repo, nodes)