# Code dedicated to the exchange of obsolescence markers

#

# Copyright 2017 Pierre-Yves David <pierre-yves.david@ens-lyon.org>

#

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

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

from __future__ import absolute_import

try:

    import StringIO as io

    StringIO = io.StringIO

except ImportError:

    import io

    StringIO = io.StringIO

from mercurial import (

    bundle2,

    error,

    exchange,

    extensions,

    lock as lockmod,

    node,

    obsolete,

    pushkey,

    util,

    wireproto,

)

from mercurial.hgweb import common as hgwebcommon

from . import (

    exthelper,

    utility,

    obsdiscovery,

)

eh = exthelper.exthelper()

eh.merge(obsdiscovery.eh)

obsexcmsg = utility.obsexcmsg

obsexcprg = utility.obsexcprg

eh.configitem('experimental', 'verbose-obsolescence-exchange')

_bestformat = max(obsolete.formats.keys())

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

### Support for subset specification in getbundle ###

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

# Adds support for the 'evo_obscommon' argument to getbundle This argument use

# the data recovered from the discovery to request only a subpart of the

# obsolete subtree.

@eh.uisetup

def addgetbundleargs(self):

    wireproto.gboptsmap['evo_obscommon'] = 'nodes'

    wireproto.gboptsmap['evo_missing_nodes'] = 'nodes'

@eh.wrapfunction(exchange, '_pullbundle2extraprepare')

def _addobscommontob2pull(orig, pullop, kwargs):

    ret = orig(pullop, kwargs)

    ui = pullop.repo.ui

    if ('obsmarkers' in kwargs and

        pullop.remote.capable('_evoext_getbundle_obscommon')):

        boundaries = obsdiscovery.buildpullobsmarkersboundaries(pullop)

        if 'common' in boundaries:

            common = boundaries['common']

            if common != pullop.common:

                obsexcmsg(ui, 'request obsmarkers for some common nodes\n')

            if common != [node.nullid]:

                kwargs['evo_obscommon'] = common

        elif 'missing' in boundaries:

            missing = boundaries['missing']

            if missing:

                obsexcmsg(ui, 'request obsmarkers for %d common nodes\n'

                          % len(missing))

            kwargs['evo_missing_nodes'] = missing

    return ret

def _getbundleobsmarkerpart(orig, bundler, repo, source, **kwargs):

    if not (set(['evo_obscommon', 'evo_missing_nodes']) & set(kwargs)):

        return orig(bundler, repo, source, **kwargs)

    if kwargs.get('obsmarkers', False):

        heads = kwargs.get('heads')

        if 'evo_obscommon' in kwargs:

            if heads is None:

                heads = repo.heads()

            obscommon = kwargs.get('evo_obscommon', ())

            assert obscommon

            obsset = repo.unfiltered().set('::%ln - ::%ln', heads, obscommon)

            subset = [c.node() for c in obsset]

        else:

            common = kwargs.get('common')

            subset = [c.node() for c in repo.unfiltered().set('only(%ln, %ln)', heads, common)]

            subset += kwargs['evo_missing_nodes']

        markers = repo.obsstore.relevantmarkers(subset)

        if util.safehasattr(bundle2, 'buildobsmarkerspart'):

            bundle2.buildobsmarkerspart(bundler, markers)

        else:

            exchange.buildobsmarkerspart(bundler, markers)

# manual wrap up in extsetup because of the wireproto.commands mapping

def _obscommon_capabilities(orig, repo, proto):

    """wrapper to advertise new capability"""

    caps = orig(repo, proto)

    if obsolete.isenabled(repo, obsolete.exchangeopt):

        caps = caps.split()

        caps.append('_evoext_getbundle_obscommon')

        caps.sort()

        caps = ' '.join(caps)

    return caps

@eh.extsetup

def extsetup_obscommon(ui):

    wireproto.gboptsmap['evo_obscommon'] = 'nodes'

    # wrap module content

    origfunc = exchange.getbundle2partsmapping['obsmarkers']

    def newfunc(*args, **kwargs):

        return _getbundleobsmarkerpart(origfunc, *args, **kwargs)

    exchange.getbundle2partsmapping['obsmarkers'] = newfunc

    extensions.wrapfunction(wireproto, 'capabilities', _obscommon_capabilities)

    # wrap command content

    oldcap, args = wireproto.commands['capabilities']

    def newcap(repo, proto):

        return _obscommon_capabilities(oldcap, repo, proto)

    wireproto.commands['capabilities'] = (newcap, args)

def _pushobsmarkers(repo, data):

    tr = lock = None

    try:

        lock = repo.lock()

        tr = repo.transaction('pushkey: obsolete markers')

        new = repo.obsstore.mergemarkers(tr, data)

        if new is not None:

            obsexcmsg(repo.ui, "%i obsolescence markers added\n" % new, True)

        tr.close()

    finally:

        lockmod.release(tr, lock)

    repo.hook('evolve_pushobsmarkers')

def srv_pushobsmarkers(repo, proto):

    """wireprotocol command"""

    fp = StringIO()

    proto.redirect()

    proto.getfile(fp)

    data = fp.getvalue()

    fp.close()

    _pushobsmarkers(repo, data)

    return wireproto.pushres(0)

def _getobsmarkersstream(repo, heads=None, common=None):

    """Get a binary stream for all markers relevant to `::<heads> - ::<common>`

    """

    revset = ''

    args = []

    repo = repo.unfiltered()

    if heads is None:

        revset = 'all()'

    elif heads:

        revset += "(::%ln)"

        args.append(heads)

    else:

        assert False, 'pulling no heads?'

    if common:

        revset += ' - (::%ln)'

        args.append(common)

    nodes = [c.node() for c in repo.set(revset, *args)]

    markers = repo.obsstore.relevantmarkers(nodes)

    obsdata = StringIO()

    for chunk in obsolete.encodemarkers(markers, True):

        obsdata.write(chunk)

    obsdata.seek(0)

    return obsdata

def srv_pullobsmarkers(repo, proto, others):

    """serves a binary stream of markers.

    Serves relevant to changeset between heads and common. The stream is prefix

    by a -string- representation of an integer. This integer is the size of the

    stream."""

    opts = wireproto.options('', ['heads', 'common'], others)

    for k, v in opts.iteritems():

        if k in ('heads', 'common'):

            opts[k] = wireproto.decodelist(v)

    obsdata = _getobsmarkersstream(repo, **opts)

    finaldata = StringIO()

    obsdata = obsdata.getvalue()

    finaldata.write('%20i' % len(obsdata))

    finaldata.write(obsdata)

    finaldata.seek(0)

    return wireproto.streamres(reader=finaldata, v1compressible=True)

abortmsg = "won't exchange obsmarkers through pushkey"

hint = "upgrade your client or server to use the bundle2 protocol"

class HTTPCompatibleAbort(hgwebcommon.ErrorResponse, error.Abort):

    def __init__(self, message, code, hint=None):

        # initialisation of each class is a bit messy.

        # We explicitly do the dispatch

        hgwebcommon.ErrorResponse.__init__(self, 410, message)

        error.Abort.__init__(self, message, hint=hint)

def forbidpushkey(repo=None, key=None, old=None, new=None):

    """prevent exchange through pushkey"""

    err = HTTPCompatibleAbort(abortmsg, 410, hint=hint)

    raise err

def forbidlistkey(repo=None, key=None, old=None, new=None):

    """prevent exchange through pushkey"""

    if obsolete.isenabled(repo, obsolete.exchangeopt):

        err = HTTPCompatibleAbort(abortmsg, 410, hint=hint)

        raise err

    return {}

@eh.uisetup

def setuppushkeyforbidding(ui):

    pushkey._namespaces['obsolete'] = (forbidpushkey, forbidlistkey)