# 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

import struct

from .i18n import _

from .node import (

    bin,

    hex,

    short,

    wdirid,

)

from . import (

    encoding,

    error,

    obsutil,

    pycompat,

    scmutil,

    txnutil,

    util,

)

# label constants

# until 3.5, bookmarks.current was the advertised name, not

# bookmarks.active, so we must use both to avoid breaking old

# custom styles

activebookmarklabel = 'bookmarks.active bookmarks.current'

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

        self._clean = True

        self._aclean = True

        nm = repo.changelog.nodemap

        tonode = bin # force local lookup

        setitem = dict.__setitem__

        try:

            with _getbkfile(repo) as bkfile:

                for line in bkfile:

                    line = line.strip()

                    if not line:

                        continue

                    try:

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

                        node = tonode(sha)

                        if node in nm:

                            refspec = encoding.tolocal(refspec)

                            setitem(self, refspec, node)

                    except (TypeError, ValueError):

                        # TypeError:

                        # - bin(...)

                        # ValueError:

                        # - node in nm, for non-20-bytes entry

                        # - split(...), for string without ' '

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

                                     % pycompat.bytestr(line))

        except IOError as inst:

            if inst.errno != errno.ENOENT:

                raise

        self._active = _readactive(repo, self)

    @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):

        raise error.ProgrammingError("use 'bookmarks.applychanges' instead")

    def _set(self, key, value):

        self._clean = False

        return dict.__setitem__(self, key, value)

    def __delitem__(self, key):

        raise error.ProgrammingError("use 'bookmarks.applychanges' instead")

    def _del(self, key):

        self._clean = False

        return dict.__delitem__(self, key)

    def update(self, *others):

        raise error.ProgrammingError("use 'bookmarks.applychanges' instead")

    def applychanges(self, repo, tr, changes):

        """Apply a list of changes to bookmarks

        """

        bmchanges = tr.changes.get('bookmarks')

        for name, node in changes:

            old = self.get(name)

            if node is None:

                self._del(name)

            else:

                self._set(name, node)

            if bmchanges is not None:

                # if a previous value exist preserve the "initial" value

                previous = bmchanges.get(name)

                if previous is not None:

                    old = previous[0]

                bmchanges[name] = (old, node)

        self._recordchange(tr)

    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 sorted(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 checkconflict(self, mark, force=False, target=None):

        """check repo for a potential clash of mark with an existing bookmark,

        branch, or hash

        If target is supplied, then check that we are moving the bookmark

        forward.

        If force is supplied, then forcibly move the bookmark to a new commit

        regardless if it is a move forward.

        If divergent bookmark are to be deleted, they will be returned as list.

        """

        cur = self._repo.changectx('.').node()

        if mark in self and not force:

            if target:

                if self[mark] == target and target == cur:

                    # re-activating a bookmark

                    return []

                rev = self._repo[target].rev()

                anc = self._repo.changelog.ancestors([rev])

                bmctx = self._repo[self[mark]]

                divs = [self._repo[b].node() for b in self

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

                # allow resolving a single divergent bookmark even if moving

                # the bookmark across branches when a revision is specified

                # that contains a divergent bookmark

                if bmctx.rev() not in anc and target in divs:

                    return divergent2delete(self._repo, [target], mark)

                deletefrom = [b for b in divs

                              if self._repo[b].rev() in anc or b == target]

                delbms = divergent2delete(self._repo, deletefrom, mark)

                if validdest(self._repo, bmctx, self._repo[target]):

                    self._repo.ui.status(

                        _("moving bookmark '%s' forward from %s\n") %

                        (mark, short(bmctx.node())))

                    return delbms

            raise error.Abort(_("bookmark '%s' already exists "

                                "(use -f to force)") % mark)

        if ((mark in self._repo.branchmap() or

             mark == self._repo.dirstate.branch()) and not force):

            raise error.Abort(

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

        if len(mark) > 3 and not force:

            try:

                shadowhash = (mark in self._repo)

            except error.LookupError:  # ambiguous identifier

                shadowhash = False

            if shadowhash:

                self._repo.ui.warn(

                    _("bookmark %s matches a changeset hash\n"

                      "(did you leave a -r out of an 'hg bookmark' "

                      "command?)\n")

                    % mark)

        return []

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 divergent2delete(repo, deletefrom, bm):

    """find divergent versions of bm on nodes in deletefrom.

    the list of bookmark to delete."""

    todelete = []

    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:

                todelete.append(mark)

    return todelete

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

    active = marks.active

    if not active:

        return False

    bmchanges = []

    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):

            bmchanges.append((active, new.node()))