# 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 __future__ import absolute_import

import errno

from .i18n import _

from .node import (

    bin,

    hex,

)

from . import (

    encoding,

    error,

    lock as lockmod,

    obsolete,

    txnutil,

    util,

)

def _getbkfile(repo):

    """Hook so that extensions that mess with the store can hook bm storage.

    For core, this just handles wether we should see pending

    bookmarks or the committed ones. Other extensions (like share)

    may need to tweak this behavior further.

    """

    fp, pending = txnutil.trypending(repo.root, repo.vfs, 'bookmarks')

    return fp

class bmstore(dict):

    """Storage for bookmarks.

    This object should do all bookmark-related reads and writes, so

    that it's fairly simple to replace the storage underlying

    bookmarks without having to clone the logic surrounding

    bookmarks. This type also should manage the active bookmark, if

    any.

    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}.

    """

    def __init__(self, repo):

        dict.__init__(self)

        self._repo = repo

        try:

            bkfile = _getbkfile(repo)

            for line in bkfile:

                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)

                try:

        except IOError as inst:

            if inst.errno != errno.ENOENT:

                raise

        self._clean = True

        self._active = _readactive(repo, self)

        self._aclean = True

    @property

    def active(self):

        return self._active

    @active.setter

    def active(self, mark):

        if mark is not None and mark not in self:

            raise AssertionError('bookmark %s does not exist!' % mark)

        self._active = mark

        self._aclean = False

    def __setitem__(self, *args, **kwargs):

        self._clean = False

        return dict.__setitem__(self, *args, **kwargs)

    def __delitem__(self, key):

        self._clean = False

        return dict.__delitem__(self, key)

    def recordchange(self, tr):

        """record that bookmarks have been changed in a transaction

        The transaction is then responsible for updating the file content."""

        tr.addfilegenerator('bookmarks', ('bookmarks',), self._write,

                            location='plain')

        tr.hookargs['bookmark_moved'] = '1'

    def _writerepo(self, repo):

        """Factored out for extensibility"""

        rbm = repo._bookmarks

        if rbm.active not in self:

            rbm.active = None

            rbm._writeactive()

        with repo.wlock():

            file_ = repo.vfs('bookmarks', 'w', atomictemp=True,

                             checkambig=True)

            try:

                self._write(file_)

            except: # re-raises

                file_.discard()

                raise

            finally:

                file_.close()

    def _writeactive(self):

        if self._aclean:

            return

        with self._repo.wlock():

            if self._active is not None:

                f = self._repo.vfs('bookmarks.current', 'w', atomictemp=True,

                                   checkambig=True)

                try:

                    f.write(encoding.fromlocal(self._active))

                finally:

                    f.close()

            else:

                self._repo.vfs.tryunlink('bookmarks.current')

        self._aclean = True

    def _write(self, fp):

        for name, node in self.iteritems():

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

        self._clean = True

        self._repo.invalidatevolatilesets()

    def expandname(self, bname):

        if bname == '.':

            if self.active:

                return self.active

            else:

                raise error.Abort(_("no active bookmark"))

        return bname

def _readactive(repo, marks):

    """

    Get the active bookmark. We can have an active bookmark that updates

    itself as we commit. This function returns the name of that bookmark.

    It is stored in .hg/bookmarks.current

    """

    mark = None

    try:

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

    except IOError as inst:

        if inst.errno != errno.ENOENT:

            raise

        return None

    try:

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

        # cheap.

        # Note that it's possible for readlines() here to raise

        # IOError, since we might be reading the active mark over

        # static-http which only tries to load the file when we try

        # to read from it.

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

        if mark == '' or mark not in marks:

            mark = None

    except IOError as inst:

        if inst.errno != errno.ENOENT:

            raise

        return None

    finally:

        file.close()

    return mark

def activate(repo, mark):

    """

    Set the given bookmark to be 'active', meaning that this bookmark will

    follow new commits that are made.

    The name is recorded in .hg/bookmarks.current

    """

    repo._bookmarks.active = mark

    repo._bookmarks._writeactive()

def deactivate(repo):

    """

    Unset the active bookmark in this repository.

    """

    repo._bookmarks.active = None

    repo._bookmarks._writeactive()

def isactivewdirparent(repo):

    """

    Tell whether the 'active' bookmark (the one that follows new commits)

    points to one of the parents of the current working directory (wdir).

    While this is normally the case, it can on occasion be false; for example,

    immediately after a pull, the active bookmark can be moved to point

    to a place different than the wdir. This is solved by running `hg update`.

    """

    mark = repo._activebookmark

    marks = repo._bookmarks

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

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

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 == '@' or '@' not in mark:

            # can't be divergent by definition

            continue

        if mark and marks[mark] in deletefrom:

            if mark != bm:

                del marks[mark]

                deleted = True

    return deleted

def headsforactive(repo):

    """Given a repo with an active bookmark, return divergent bookmark nodes.

    Args:

      repo: A repository with an active bookmark.

    Returns:

      A list of binary node ids that is the full list of other

      revisions with bookmarks divergent from the active bookmark. If

      there were no divergent bookmarks, then this list will contain

      only one entry.

    """

    if not repo._activebookmark:

        raise ValueError(

            'headsforactive() only makes sense with an active bookmark')

    name = repo._activebookmark.split('@', 1)[0]

    heads = []

    for mark, n in repo._bookmarks.iteritems():

        if mark.split('@', 1)[0] == name:

            heads.append(n)

    return heads

def calculateupdate(ui, repo, checkout):

    '''Return a tuple (targetrev, movemarkfrom) indicating the rev to

    check out and where to move the active bookmark from, if needed.'''

    movemarkfrom = None

    if checkout is None:

        activemark = repo._activebookmark

        if isactivewdirparent(repo):

            movemarkfrom = repo['.'].node()

        elif activemark:

            ui.status(_("updating to active bookmark %s\n") % activemark)

            checkout = activemark

    return (checkout, movemarkfrom)

def update(repo, parents, node):

    deletefrom = parents

    marks = repo._bookmarks

    update = False

    active = marks.active

    if not active:

        return False

    if marks[active] in parents:

        new = repo[node]

        divs = [repo[b] for b in marks

                if b.split('@', 1)[0] == active.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 validdest(repo, repo[marks[active]], new):

            marks[active] = new.node()

            update = True

    if deletedivergent(repo, deletefrom, active):

        update = True

    if update:

        lock = tr = None

        try:

            lock = repo.lock()

            tr = repo.transaction('bookmark')

            marks.recordchange(tr)

            tr.close()

        finally:

            lockmod.release(tr, lock)

    return update

def listbinbookmarks(repo):

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

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

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

    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('@')):

            yield k, v

def listbookmarks(repo):

    d = {}

    for book, node in listbinbookmarks(repo):

        d[book] = hex(node)

    return d

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

    w = l = tr = None

    try:

        w = repo.wlock()

        l = repo.lock()

        tr = repo.transaction('bookmarks')

        marks = repo._bookmarks

        existing = hex(marks.get(key, ''))

        if existing != old and existing != new:

            return False

        if new == '':

            del marks[key]

        else:

            if new not in repo:

                return False

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

        marks.recordchange(tr)

        tr.close()

        return True

    finally:

        lockmod.release(tr, l, w)

def comparebookmarks(repo, srcmarks, dstmarks, targets=None):

    '''Compare bookmarks between srcmarks and dstmarks

    This returns tuple "(addsrc, adddst, advsrc, advdst, diverge,

    differ, invalid)", each are list of bookmarks below:

    :addsrc:  added on src side (removed on dst side, perhaps)

    :adddst:  added on dst side (removed on src side, perhaps)

    :advsrc:  advanced on src side

    :advdst:  advanced on dst side

    :diverge: diverge

    :differ:  changed, but changeset referred on src is unknown on dst

    :invalid: unknown on both side

    :same:    same on both side

    Each elements of lists in result tuple is tuple "(bookmark name,

    changeset ID on source side, changeset ID on destination

    side)". Each changeset IDs are 40 hexadecimal digit string or

    None.

    Changeset IDs of tuples in "addsrc", "adddst", "differ" or

     "invalid" list may be unknown for repo.

    If "targets" is specified, only bookmarks listed in it are

    examined.

    '''

    if targets:

        bset = set(targets)

    else:

        srcmarkset = set(srcmarks)

        dstmarkset = set(dstmarks)

        bset = srcmarkset | dstmarkset

    results = ([], [], [], [], [], [], [], [])

    addsrc = results[0].append

    adddst = results[1].append

    advsrc = results[2].append

    advdst = results[3].append

    diverge = results[4].append

    differ = results[5].append

    invalid = results[6].append

    same = results[7].append

    for b in sorted(bset):

        if b not in srcmarks: