# 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 hex

from mercurial import encoding, error, util, obsolete

import errno, os

class bmstore(dict):

    """Storage for bookmarks.

    This object should do all bookmark reads and writes, so that it's

    fairly simple to replace the storage underlying bookmarks without

    having to clone the logic surrounding bookmarks.

    This particular bmstore implementation stores bookmarks as

    {hash}\s{name}\n (the same format as localtags) in

    .hg/bookmarks. The mapping is stored as {name: nodeid}.

    This class does NOT handle the "current" bookmark state at this

    time.

    """

    def __init__(self, repo):

        dict.__init__(self)

        self._repo = repo

        try:

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

                line = line.strip()

                if not line:

                    continue

                if ' ' not in line:

                    repo.ui.warn(_('malformed line in .hg/bookmarks: %r\n')

                                 % line)

                    continue

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

                refspec = encoding.tolocal(refspec)

                try:

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

                except LookupError:

                    pass

        except IOError, inst:

            if inst.errno != errno.ENOENT:

                raise

    def write(self):

        '''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.

        '''

        repo = self._repo

        if repo._bookmarkcurrent not in self:

            setcurrent(repo, None)

        wlock = repo.wlock()

        try:

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

            for name, node in self.iteritems():

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

            file.close()

            # 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 readcurrent(repo):

    '''Get the current bookmark

    If we use gittish 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

    try:

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

    except IOError, inst:

        if inst.errno != errno.ENOENT:

            raise

        return None

    try:

        # No readline() in osutil.posixfile, reading everything is cheap

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

        if mark == '' or mark not in repo._bookmarks:

            mark = None

    finally:

        file.close()

    return mark

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

    if mark not in repo._bookmarks:

        mark = ''

    wlock = repo.wlock()

    try:

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

        file.write(encoding.fromlocal(mark))

        file.close()

    finally:

        wlock.release()

    repo._bookmarkcurrent = mark

def unsetcurrent(repo):

    wlock = repo.wlock()

    try:

        try:

            util.unlink(repo.join('bookmarks.current'))

            repo._bookmarkcurrent = None

        except OSError, inst:

            if inst.errno != errno.ENOENT:

                raise

    finally:

        wlock.release()

def iscurrent(repo, mark=None, parents=None):

    '''Tell whether the current bookmark is also active

    I.e., the bookmark listed in .hg/bookmarks.current also points to a

    parent of the working directory.

    '''

    if not mark:

        mark = repo._bookmarkcurrent

    if not parents:

        parents = [p.node() for p in repo[None].parents()]

    marks = repo._bookmarks

    return (mark in marks and marks[mark] in parents)

def updatecurrentbookmark(repo, oldnode, curbranch):

    try:

        return update(repo, oldnode, repo.branchtip(curbranch))

    except error.RepoLookupError:

        if curbranch == "default": # no default branch!

            return update(repo, oldnode, repo.lookup("tip"))

        else:

            raise util.Abort(_("branch %s not found") % curbranch)

def deletedivergent(repo, deletefrom, bm):

    '''Delete divergent versions of bm on nodes in deletefrom.

    Return True if at least one bookmark was deleted, False otherwise.'''

    deleted = False

    marks = repo._bookmarks

    divergent = [b for b in marks if b.split('@', 1)[0] == bm.split('@', 1)[0]]

    for mark in divergent:

        if mark and marks[mark] in deletefrom:

            if mark != bm:

                del marks[mark]

                deleted = True

    return deleted

def update(repo, parents, node):

    deletefrom = parents

    marks = repo._bookmarks

    update = False

    cur = repo._bookmarkcurrent

    if not cur:

        return False

    if marks[cur] in parents:

        old = repo[marks[cur]]

        new = repo[node]

        divs = [repo[b] for b in marks

                if b.split('@', 1)[0] == cur.split('@', 1)[0]]

        anc = repo.changelog.ancestors([new.rev()])

        deletefrom = [b.node() for b in divs if b.rev() in anc or b == new]

        if old.descendant(new):

            marks[cur] = new.node()

            update = True

    if deletedivergent(repo, deletefrom, cur):

        update = True

    if update:

        marks.write()

    return update

def listbookmarks(repo):

    # We may try to list bookmarks on a repo type that does not

    # support it (e.g., statichttprepository).

    marks = getattr(repo, '_bookmarks', {})

    d = {}

    hasnode = repo.changelog.hasnode

    for k, v in marks.iteritems():

        # don't expose local divergent bookmarks

        if hasnode(v) and ('@' not in k or k.endswith('@')):

            d[k] = hex(v)

    return d

def pushbookmark(repo, key, old, new):

    w = repo.wlock()

    try:

        marks = repo._bookmarks

        if hex(marks.get(key, '')) != old:

            return False

        if new == '':

            del marks[key]

        else:

            if new not in repo:

                return False

            marks[key] = repo[new].node()

        marks.write()

        return True

    finally:

        w.release()

def updatefromremote(ui, repo, remotemarks, path):

    ui.debug("checking for updated bookmarks\n")

    changed = False

    localmarks = repo._bookmarks

    for k in sorted(remotemarks):

        if k in localmarks:

            nr, nl = remotemarks[k], localmarks[k]

            if nr in repo:

                cr = repo[nr]

                cl = repo[nl]

                if cl.rev() >= cr.rev():

                    continue

                if validdest(repo, cl, cr):

                    localmarks[k] = cr.node()

                    changed = True

                    ui.status(_("updating bookmark %s\n") % k)

                else:

                    if k == '@':

                        kd = ''

                    else:

                        kd = k

                    # find a unique @ suffix

                    for x in range(1, 100):

                        n = '%s@%d' % (kd, x)

                        if n not in localmarks:

                            break

                    # try to use an @pathalias suffix

                    # if an @pathalias already exists, we overwrite (update) it

                    for p, u in ui.configitems("paths"):

                        if path == u:

                            n = '%s@%s' % (kd, p)

                    localmarks[n] = cr.node()

                    changed = True

                    ui.warn(_("divergent bookmark %s stored as %s\n") % (k, n))

        elif remotemarks[k] in repo:

            # add remote bookmarks for changes we already have

            localmarks[k] = repo[remotemarks[k]].node()

            changed = True

            ui.status(_("adding remote bookmark %s\n") % k)

    if changed:

        localmarks.write()

def diff(ui, dst, src):

    ui.status(_("searching for changed bookmarks\n"))

    smarks = src.listkeys('bookmarks')

    dmarks = dst.listkeys('bookmarks')

    diff = sorted(set(smarks) - set(dmarks))

    for k in diff:

        mark = ui.debugflag and smarks[k] or smarks[k][:12]

        ui.write("   %-25s %s\n" % (k, mark))

    if len(diff) <= 0:

        ui.status(_("no changed bookmarks found\n"))

        return 1

    return 0

def validdest(repo, old, new):

    """Is the new bookmark destination a valid update from the old one"""

    repo = repo.unfiltered()

    if old == new:

        # Old == new -> nothing to update.

        return False

    elif not old:

        # old is nullrev, anything is valid.

        # (new != nullrev has been excluded by the previous check)

        return True

    elif repo.obsstore:

        return new.node() in obsolete.foreground(repo, [old.node()])

    else:

        # still an independant clause as it is lazyer (and therefore faster)

        return old.descendant(new)