# logexchange.py

#

# Copyright 2017 Augie Fackler <raf@durin42.com>

# Copyright 2017 Sean Farley <sean@farley.io>

#

# 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 .node import hex

from . import (

    vfs as vfsmod,

)

# directory name in .hg/ in which remotenames files will be present

remotenamedir = 'logexchange'

def readremotenamefile(repo, filename):

    """

    reads a file from .hg/logexchange/ directory and yields it's content

    filename: the file to be read

    yield a tuple (node, remotepath, name)

    """

    vfs = vfsmod.vfs(repo.vfs.join(remotenamedir))

    if not vfs.exists(filename):

        return

    f = vfs(filename)

    lineno = 0

    for line in f:

        line = line.strip()

        if not line:

            continue

        # contains the version number

        if lineno == 0:

            lineno += 1

        try:

            node, remote, rname = line.split('\0')

            yield node, remote, rname

        except ValueError:

            pass

    f.close()

def readremotenames(repo):

    """

    read the details about the remotenames stored in .hg/logexchange/ and

    yields a tuple (node, remotepath, name). It does not yields information

    about whether an entry yielded is branch or bookmark. To get that

    information, call the respective functions.

    """

    for bmentry in readremotenamefile(repo, 'bookmarks'):

        yield bmentry

    for branchentry in readremotenamefile(repo, 'branches'):

        yield branchentry

def writeremotenamefile(repo, remotepath, names, nametype):

    vfs = vfsmod.vfs(repo.vfs.join(remotenamedir))

    f = vfs(nametype, 'w', atomictemp=True)

    # write the storage version info on top of file

    # version '0' represents the very initial version of the storage format

    f.write('0\n\n')

    olddata = set(readremotenamefile(repo, nametype))

    # re-save the data from a different remote than this one.

    for node, oldpath, rname in sorted(olddata):

        if oldpath != remotepath:

            f.write('%s\0%s\0%s\n' % (node, oldpath, rname))

    for name, node in sorted(names.iteritems()):

        if nametype == "branches":

            for n in node:

                f.write('%s\0%s\0%s\n' % (n, remotepath, name))

        elif nametype == "bookmarks":

            if node:

                f.write('%s\0%s\0%s\n' % (node, remotepath, name))

    f.close()

def saveremotenames(repo, remotepath, branches=None, bookmarks=None):

    """

    save remotenames i.e. remotebookmarks and remotebranches in their

    respective files under ".hg/logexchange/" directory.

    """

    wlock = repo.wlock()

    try:

        if bookmarks:

            writeremotenamefile(repo, remotepath, bookmarks, 'bookmarks')

        if branches:

            writeremotenamefile(repo, remotepath, branches, 'branches')

    finally:

        wlock.release()

def pullremotenames(localrepo, remoterepo):

    """

    pulls bookmarks and branches information of the remote repo during a

    pull or clone operation.

    localrepo is our local repository

    remoterepo is the peer instance

    """

    bookmarks = remoterepo.listkeys('bookmarks')

    # on a push, we don't want to keep obsolete heads since

    # they won't show up as heads on the next pull, so we

    # remove them here otherwise we would require the user

    # to issue a pull to refresh the storage

    bmap = {}

    repo = localrepo.unfiltered()

    for branch, nodes in remoterepo.branchmap().iteritems():

        bmap[branch] = []

        for node in nodes:

            if node in repo and not repo[node].obsolete():

                bmap[branch].append(hex(node))

    saveremotenames(localrepo, remotepath, bmap, bookmarks)