# 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

import errno

import socket

from mercurial import (

    error,

    exchange,

    extensions,

    httppeer,

    localrepo,

    lock as lockmod,

    node,

    obsolete,

    util,

    wireproto,

)

from mercurial.hgweb import hgweb_mod

from mercurial.i18n import _

from . import (

    exthelper,

    utility,

    obsdiscovery,

)

eh = exthelper.exthelper()

eh.merge(obsdiscovery.eh)

obsexcmsg = utility.obsexcmsg

obsexcprg = utility.obsexcprg

_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)

# 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

# The wireproto.streamres API changed, handling chunking and compression

# directly. Handle either case.

if util.safehasattr(wireproto.abstractserverproto, 'groupchunks'):

    # We need to handle chunking and compression directly

    def streamres(d, proto):

        return wireproto.streamres(proto.groupchunks(d))

else:

    # Leave chunking and compression to streamres

    def streamres(d, proto):

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

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 streamres(finaldata, proto)

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

### Support for old legacy exchange methods ###

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

class pushobsmarkerStringIO(StringIO):

    """hacky string io for progress"""

    @util.propertycache

    def length(self):

        return len(self.getvalue())

    def read(self, size=None):

        obsexcprg(self.ui, self.tell(), unit=_("bytes"), total=self.length)

        return StringIO.read(self, size)

    def __iter__(self):

        d = self.read(4096)

        while d:

            yield d

            d = self.read(4096)

# compat-code: _pushobsolete

#

# the _pushobsolete function is a core function used to exchange

# obsmarker with repository that does not support bundle2

@eh.wrapfunction(exchange, '_pushobsolete')

def _pushobsolete(orig, pushop):

    """utility function to push obsolete markers to a remote"""

    if not obsolete.isenabled(pushop.repo, obsolete.exchangeopt):

        return

    if 'obsmarkers' in pushop.stepsdone:

        return

    pushop.stepsdone.add('obsmarkers')

    if pushop.cgresult == 0:

        return

    pushop.ui.debug('try to push obsolete markers to remote\n')

    repo = pushop.repo

    remote = pushop.remote

    if (repo.obsstore and 'obsolete' in remote.listkeys('namespaces')):

        markers = pushop.outobsmarkers

        if not markers:

            obsexcmsg(repo.ui, "no marker to push\n")

        elif remote.capable('_evoext_pushobsmarkers_0'):

            msg = ('the remote repository use years old versions of Mercurial'

                   ' and evolve\npushing obsmarker using legacy method\n')

            repo.ui.warn(msg)

            repo.ui.warn('(please upgrade your server)\n')

            obsdata = pushobsmarkerStringIO()

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

                obsdata.write(chunk)

            obsdata.seek(0)

            obsdata.ui = repo.ui

            obsexcmsg(repo.ui, "pushing %i obsolescence markers (%i bytes)\n"

                               % (len(markers), len(obsdata.getvalue())),

                      True)

            remote.evoext_pushobsmarkers_0(obsdata)

            obsexcprg(repo.ui, None)

        else:

            # XXX core could be able do the same things but without the debug

            # and progress output.

            msg = ('the remote repository usea years old version of Mercurial'

                   ' and not evolve extension\n')

            repo.ui.warn(msg)

            msg = 'pushing obsmarker using and extremely slow legacy method\n'

            repo.ui.warn(msg)

            repo.ui.warn('(please upgrade your server and enable evolve.serveronly on it)\n')

            rslts = []

            remotedata = obsolete._pushkeyescape(markers).items()

            totalbytes = sum(len(d) for k, d in remotedata)

            sentbytes = 0

            obsexcmsg(repo.ui, "pushing %i obsolescence markers in %i "

                               "pushkey payload (%i bytes)\n"

                               % (len(markers), len(remotedata), totalbytes),

                      True)

            for key, data in remotedata:

                obsexcprg(repo.ui, sentbytes, item=key, unit=_("bytes"),

                          total=totalbytes)

                rslts.append(remote.pushkey('obsolete', key, '', data))

                sentbytes += len(data)

                obsexcprg(repo.ui, sentbytes, item=key, unit=_("bytes"),

                          total=totalbytes)

            obsexcprg(repo.ui, None)

            if [r for r in rslts if not r]:

                msg = _('failed to push some obsolete markers!\n')

                repo.ui.warn(msg)

        obsexcmsg(repo.ui, "DONE\n")

# Supporting legacy way to push obsmarker so that old client can still push

# them somewhat efficiently

@eh.addattr(wireproto.wirepeer, 'evoext_pushobsmarkers_0')

def client_pushobsmarkers(self, obsfile):

    """wireprotocol peer method"""

    self.requirecap('_evoext_pushobsmarkers_0',

                    _('push obsolete markers faster'))

    ret, output = self._callpush('evoext_pushobsmarkers_0', obsfile)

    for l in output.splitlines(True):

        self.ui.status(_('remote: '), l)

    return ret

@eh.addattr(httppeer.httppeer, 'evoext_pushobsmarkers_0')

def httpclient_pushobsmarkers(self, obsfile):

    """httpprotocol peer method

    (Cannot simply use _callpush as http is doing some special handling)"""

    self.requirecap('_evoext_pushobsmarkers_0',

                    _('push obsolete markers faster'))

    try:

        r = self._call('evoext_pushobsmarkers_0', data=obsfile)

        vals = r.split('\n', 1)

        if len(vals) < 2:

            raise error.ResponseError(_("unexpected response:"), r)

        for l in vals[1].splitlines(True):

            if l.strip():

                self.ui.status(_('remote: '), l)

        return vals[0]

    except socket.error as err:

        if err.args[0] in (errno.ECONNRESET, errno.EPIPE):

            raise error.Abort(_('push failed: %s') % err.args[1])

        raise error.Abort(err.args[1])

@eh.wrapfunction(localrepo.localrepository, '_restrictcapabilities')

def local_pushobsmarker_capabilities(orig, repo, caps):

    caps = orig(repo, caps)

    caps.add('_evoext_pushobsmarkers_0')

    return caps

@eh.addattr(localrepo.localpeer, 'evoext_pushobsmarkers_0')

def local_pushobsmarkers(peer, obsfile):

    data = obsfile.read()

    _pushobsmarkers(peer._repo, data)

# compat-code: _pullobsolete

#

# the _pullobsolete function is a core function used to exchange

# obsmarker with repository that does not support bundle2

@eh.wrapfunction(exchange, '_pullobsolete')

def _pullobsolete(orig, pullop):

    if not obsolete.isenabled(pullop.repo, obsolete.exchangeopt):

        return None

    if 'obsmarkers' in pullop.stepsdone:

        return None

    wirepull = pullop.remote.capable('_evoext_pullobsmarkers_0')

    if 'obsolete' not in pullop.remote.listkeys('namespaces'):

        return None # remote opted out of obsolescence marker exchange

    if not wirepull:

        return orig(pullop)

    tr = None

    ui = pullop.repo.ui

    boundaries = obsdiscovery.buildpullobsmarkersboundaries(pullop, bundle2=False)