# Mercurial bookmark support code

#

# Copyright 2008 David Soria Parra <dsp@php.net>

#

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

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

from mercurial.i18n import _

from mercurial.node import nullid, nullrev, bin, hex, short

from mercurial import encoding

import os

def read(repo):

    '''Parse .hg/bookmarks file and return a dictionary

    Bookmarks are stored as {HASH}\\s{NAME}\\n (localtags format) values

    in the .hg/bookmarks file.

    Read the file and return a (name=>nodeid) dictionary

    '''

    try:

        bookmarks = {}

        for line in repo.opener('bookmarks'):

            sha, refspec = line.strip().split(' ', 1)

            refspec = encoding.tolocal(refspec)

            bookmarks[refspec] = repo.changelog.lookup(sha)

    except:

        pass

    return bookmarks

def readcurrent(repo):

    '''Get the current bookmark

    If we use gittishsh branches we have a current bookmark that

    we are on. This function returns the name of the bookmark. It

    is stored in .hg/bookmarks.current

    '''

    mark = None

    if os.path.exists(repo.join('bookmarks.current')):

        file = repo.opener('bookmarks.current')

        # No readline() in posixfile_nt, reading everything is cheap

        mark = (file.readlines() or [''])[0]

        if mark == '':

            mark = None

        file.close()

    return mark

def write(repo):

    '''Write bookmarks

    Write the given bookmark => hash dictionary to the .hg/bookmarks file

    in a format equal to those of localtags.

    We also store a backup of the previous state in undo.bookmarks that

    can be copied back on rollback.

    '''

    refs = repo._bookmarks

    try:

        bms = repo.opener('bookmarks').read()

    except IOError:

        bms = ''

    repo.opener('undo.bookmarks', 'w').write(bms)

    if repo._bookmarkcurrent not in refs:

        setcurrent(repo, None)

    wlock = repo.wlock()

    try:

        file = repo.opener('bookmarks', 'w', atomictemp=True)

        for refspec, node in refs.iteritems():

            file.write("%s %s\n" % (hex(node), encoding.fromlocal(refspec)))

        file.rename()

        # touch 00changelog.i so hgweb reloads bookmarks (no lock needed)

        try:

            os.utime(repo.sjoin('00changelog.i'), None)

        except OSError:

            pass

    finally:

        wlock.release()

def setcurrent(repo, mark):

    '''Set the name of the bookmark that we are currently on

    Set the name of the bookmark that we are on (hg update <bookmark>).

    The name is recorded in .hg/bookmarks.current

    '''

    current = repo._bookmarkcurrent

    if current == mark:

        return

    refs = repo._bookmarks

    # do not update if we do update to a rev equal to the current bookmark

    if (mark and mark not in refs and

        current and refs[current] == repo.changectx('.').node()):

        return

    if mark not in refs:

        mark = ''

    wlock = repo.wlock()

    try:

        file = repo.opener('bookmarks.current', 'w', atomictemp=True)

        file.write(mark)

        file.rename()

    finally:

        wlock.release()

    repo._bookmarkcurrent = mark

def update(repo, parents, node):

    marks = repo._bookmarks

    update = False

    if repo.ui.configbool('bookmarks', 'track.current'):

        mark = repo._bookmarkcurrent

        if mark and marks[mark] in parents:

            marks[mark] = node

            update = True

    else:

        for mark, n in marks.items():

            if n in parents:

                marks[mark] = node

                update = True

    if update:

        write(repo)