# Mercurial extension to provide the 'hg bookmark' command

#

# 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.

'''track a line of development with movable markers

Bookmarks are local movable markers to changesets. Every bookmark

points to a changeset identified by its hash. If you commit a

changeset that is based on a changeset that has a bookmark on it, the

bookmark shifts to the new changeset.

It is possible to use bookmark names in every revision lookup (e.g. hg

merge, hg update).

By default, when several bookmarks point to the same changeset, they

will all move forward together. It is possible to obtain a more

git-like experience by adding the following configuration option to

your .hgrc::

  [bookmarks]

  track.current = True

This will cause Mercurial to track the bookmark that you are currently

using, and only update it. This is similar to git's approach to

branching.

'''

from mercurial.i18n import _

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

from mercurial import util, commands, localrepo, repair, extensions

import os

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

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

        util.copyfile(repo.join('bookmarks'), repo.join('undo.bookmarks'))

    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), refspec))

        file.rename()

    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 bookmark(ui, repo, mark=None, rev=None, force=False, delete=False, rename=None):

    '''track a line of development with movable markers

    Bookmarks are pointers to certain commits that move when

    committing. Bookmarks are local. They can be renamed, copied and

    deleted. It is possible to use bookmark names in 'hg merge' and

    'hg update' to merge and update respectively to a given bookmark.

    You can use 'hg bookmark NAME' to set a bookmark on the working

    directory's parent revision with the given name. If you specify

    a revision using -r REV (where REV may be an existing bookmark),

    the bookmark is assigned to that revision.

    '''

    hexfn = ui.debugflag and hex or short

    marks = repo._bookmarks

    cur   = repo.changectx('.').node()

    if rename:

        if rename not in marks:

            raise util.Abort(_("a bookmark of this name does not exist"))

        if mark in marks and not force:

            raise util.Abort(_("a bookmark of the same name already exists"))

        if mark is None:

            raise util.Abort(_("new bookmark name required"))

        marks[mark] = marks[rename]

        del marks[rename]

        if repo._bookmarkcurrent == rename:

            setcurrent(repo, mark)

        write(repo)

        return

    if delete:

        if mark is None:

            raise util.Abort(_("bookmark name required"))

        if mark not in marks:

            raise util.Abort(_("a bookmark of this name does not exist"))

        if mark == repo._bookmarkcurrent:

            setcurrent(repo, None)

        del marks[mark]

        write(repo)

        return

    if mark != None:

        if "\n" in mark:

            raise util.Abort(_("bookmark name cannot contain newlines"))

        mark = mark.strip()

        if mark in marks and not force:

            raise util.Abort(_("a bookmark of the same name already exists"))

        if ((mark in repo.branchtags() or mark == repo.dirstate.branch())

            and not force):

            raise util.Abort(

                _("a bookmark cannot have the name of an existing branch"))

        if rev:

            marks[mark] = repo.lookup(rev)

        else:

            marks[mark] = repo.changectx('.').node()

            setcurrent(repo, mark)

        write(repo)

        return

    if mark is None:

        if rev:

            raise util.Abort(_("bookmark name required"))

        if len(marks) == 0:

            ui.status("no bookmarks set\n")

        else:

            for bmark, n in marks.iteritems():

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

                    current = repo._bookmarkcurrent

                    prefix = (bmark == current and n == cur) and '*' or ' '

                else:

                    prefix = (n == cur) and '*' or ' '

                if ui.quiet:

                    ui.write("%s\n" % bmark)

                else:

                    ui.write(" %s %-25s %d:%s\n" % (

                        prefix, bmark, repo.changelog.rev(n), hexfn(n)))

        return

def _revstostrip(changelog, node):

    srev = changelog.rev(node)

    tostrip = [srev]

    saveheads = []

    for r in xrange(srev, len(changelog)):

        parents = changelog.parentrevs(r)

        if parents[0] in tostrip or parents[1] in tostrip:

            tostrip.append(r)

            if parents[1] != nullrev:

                for p in parents:

                    if p not in tostrip and p > srev:

                        saveheads.append(p)

    return [r for r in tostrip if r not in saveheads]

def strip(oldstrip, ui, repo, node, backup="all"):

    """Strip bookmarks if revisions are stripped using

    the mercurial.strip method. This usually happens during

    qpush and qpop"""

    revisions = _revstostrip(repo.changelog, node)

    marks = repo._bookmarks

    update = []

    for mark, n in marks.iteritems():

        if repo.changelog.rev(n) in revisions:

            update.append(mark)

    oldstrip(ui, repo, node, backup)

    if len(update) > 0:

        for m in update:

            marks[m] = repo.changectx('.').node()

        write(repo)

def reposetup(ui, repo):

    if not repo.local():

        return

    class bookmark_repo(repo.__class__):

        @util.propertycache

        def _bookmarks(self):

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

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

            in the .hg/bookmarks file. They are read returned as a dictionary

            with name => hash values.

            '''

            try:

                bookmarks = {}

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

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

                    bookmarks[refspec] = super(bookmark_repo, self).lookup(sha)

            except:

                pass

            return bookmarks

        @util.propertycache

        def _bookmarkcurrent(self):

            '''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(self.join('bookmarks.current')):

                file = self.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 rollback(self):

            if os.path.exists(self.join('undo.bookmarks')):

                util.rename(self.join('undo.bookmarks'), self.join('bookmarks'))

            return super(bookmark_repo, self).rollback()

        def lookup(self, key):

            if key in self._bookmarks:

                key = self._bookmarks[key]

            return super(bookmark_repo, self).lookup(key)

        def _bookmarksupdate(self, parents, node):

            marks = self._bookmarks

            update = False

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

                mark = self._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(self)

        def commitctx(self, ctx, error=False):

            """Add a revision to the repository and

            move the bookmark"""

            wlock = self.wlock() # do both commit and bookmark with lock held

            try:

                node  = super(bookmark_repo, self).commitctx(ctx, error)

                if node is None:

                    return None

                parents = self.changelog.parents(node)

                if parents[1] == nullid:

                    parents = (parents[0],)

                self._bookmarksupdate(parents, node)

                return node

            finally:

                wlock.release()

        def addchangegroup(self, source, srctype, url, emptyok=False):

            parents = self.dirstate.parents()

            result = super(bookmark_repo, self).addchangegroup(

                source, srctype, url, emptyok)

            if result > 1:

                # We have more heads than before

                return result

            node = self.changelog.tip()

            self._bookmarksupdate(parents, node)

            return result

        def _findtags(self):

            """Merge bookmarks with normal tags"""

            (tags, tagtypes) = super(bookmark_repo, self)._findtags()

            tags.update(self._bookmarks)

            return (tags, tagtypes)

    repo.__class__ = bookmark_repo

def uisetup(ui):

    extensions.wrapfunction(repair, "strip", strip)

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

        extensions.wrapcommand(commands.table, 'update', updatecurbookmark)

def updatecurbookmark(orig, ui, repo, *args, **opts):

    '''Set the current bookmark

    If the user updates to a bookmark we update the .hg/bookmarks.current

    file.

    '''

    res = orig(ui, repo, *args, **opts)

    rev = opts['rev']

    if not rev and len(args) > 0:

        rev = args[0]

    setcurrent(repo, rev)

    return res

cmdtable = {

    "bookmarks":

        (bookmark,

         [('f', 'force', False, _('force')),

          ('r', 'rev', '', _('revision')),

          ('d', 'delete', False, _('delete a given bookmark')),

          ('m', 'rename', '', _('rename a given bookmark'))],

         _('hg bookmarks [-f] [-d] [-m NAME] [-r REV] [NAME]')),

}