# Copyright 2017 Facebook, Inc.

#

# 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

from mercurial.i18n import _

from mercurial import (

    bundle2,

    changegroup,

    error,

    extensions,

    revsetlang,

    util,

)

from . import common

isremotebooksenabled = common.isremotebooksenabled

scratchbranchparttype = 'b2x:infinitepush'

def getscratchbranchparts(repo, peer, outgoing, ui, bookmark):

    if not outgoing.missing:

        raise error.Abort(_('no commits to push'))

    if scratchbranchparttype not in bundle2.bundle2caps(peer):

        raise error.Abort(_('no server support for %r') % scratchbranchparttype)

    _validaterevset(repo, revsetlang.formatspec('%ln', outgoing.missing),

                    bookmark)

    supportedversions = changegroup.supportedoutgoingversions(repo)

    # Explicitly avoid using '01' changegroup version in infinitepush to

    # support general delta

    supportedversions.discard('01')

    cgversion = min(supportedversions)

    _handlelfs(repo, outgoing.missing)

    cg = changegroup.makestream(repo, outgoing, cgversion, 'push')

    params = {}

    params['cgversion'] = cgversion

    if bookmark:

        params['bookmark'] = bookmark

        # 'prevbooknode' is necessary for pushkey reply part

        params['bookprevnode'] = ''

        bookmarks = repo._bookmarks

        if bookmark in bookmarks:

            params['bookprevnode'] = bookmarks.changectx(bookmark).hex()

    # Do not send pushback bundle2 part with bookmarks if remotenames extension

    # is enabled. It will be handled manually in `_push()`

    if not isremotebooksenabled(ui):

        params['pushbackbookmarks'] = '1'

    parts = []

    # .upper() marks this as a mandatory part: server will abort if there's no

    #  handler

    parts.append(bundle2.bundlepart(

        scratchbranchparttype.upper(),

        advisoryparams=params.iteritems(),

        data=cg))

    return parts

def _validaterevset(repo, revset, bookmark):

    """Abort if the revs to be pushed aren't valid for a scratch branch."""

    if not repo.revs(revset):

        raise error.Abort(_('nothing to push'))

    if bookmark:

        # Allow bundle with many heads only if no bookmark is specified

        heads = repo.revs('heads(%r)', revset)

        if len(heads) > 1:

            raise error.Abort(

                _('cannot push more than one head to a scratch branch'))

def _handlelfs(repo, missing):

    '''Special case if lfs is enabled

    If lfs is enabled then we need to call prepush hook

    to make sure large files are uploaded to lfs

    '''

    try:

        lfsmod = extensions.find('lfs')

        lfsmod.wrapper.uploadblobsfromrevs(repo, missing)

    except KeyError:

        # Ignore if lfs extension is not enabled

        return

class copiedpart(object):

    """a copy of unbundlepart content that can be consumed later"""

    def __init__(self, part):

        # copy "public properties"

        self.type = part.type

        self.id = part.id

        self.mandatory = part.mandatory

        self.mandatoryparams = part.mandatoryparams

        self.advisoryparams = part.advisoryparams

        self.params = part.params

        self.mandatorykeys = part.mandatorykeys

        # copy the buffer

        self._io = util.stringio(part.read())

    def consume(self):

        return

    def read(self, size=None):

        if size is None:

            return self._io.read()

        else:

            return self._io.read(size)