# merge.py - directory-level update/merge handling for Mercurial

#

# Copyright 2006, 2007 Matt Mackall <mpm@selenic.com>

#

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

# of the GNU General Public License, incorporated herein by reference.

from node import nullid, nullrev

from i18n import _

import errno, util, os, filemerge, copies

def _checkunknown(wctx, mctx):

    "check for collisions between unknown files and files in mctx"

    for f in wctx.unknown():

        if f in mctx and mctx[f].cmp(wctx[f].data()):

            raise util.Abort(_("untracked file in working directory differs"

                               " from file in requested revision: '%s'") % f)

def _checkcollision(mctx):

    "check for case folding collisions in the destination context"

    folded = {}

    for fn in mctx:

        fold = fn.lower()

        if fold in folded:

            raise util.Abort(_("case-folding collision between %s and %s")

                             % (fn, folded[fold]))

        folded[fold] = fn

def _forgetremoved(wctx, mctx, branchmerge):

    """

    Forget removed files

    If we're jumping between revisions (as opposed to merging), and if

    neither the working directory nor the target rev has the file,

    then we need to remove it from the dirstate, to prevent the

    dirstate from listing the file when it is no longer in the

    manifest.

    If we're merging, and the other revision has removed a file

    that is not present in the working directory, we need to mark it

    as removed.

    """

    action = []

    state = branchmerge and 'r' or 'f'

    for f in wctx.deleted():

        if f not in mctx:

            action.append((f, state))

    if not branchmerge:

        for f in wctx.removed():

            if f not in mctx:

                action.append((f, "f"))

    return action

def manifestmerge(repo, p1, p2, pa, overwrite, partial):

    """

    Merge p1 and p2 with ancestor ma and generate merge action list

    overwrite = whether we clobber working files

    partial = function to filter file lists

    """

    repo.ui.note(_("resolving manifests\n"))

    repo.ui.debug(_(" overwrite %s partial %s\n") % (overwrite, bool(partial)))

    repo.ui.debug(_(" ancestor %s local %s remote %s\n") % (pa, p1, p2))

    m1 = p1.manifest()

    m2 = p2.manifest()

    ma = pa.manifest()

    backwards = (pa == p2)

    action = []

    copy, copied, diverge = {}, {}, {}

    def fmerge(f, f2=None, fa=None):

        """merge flags"""

        if not f2:

            f2 = f

            fa = f

        a, m, n = ma.flags(fa), m1.flags(f), m2.flags(f2)

        if m == n: # flags agree

            return m # unchanged

        if m and n: # flags are set but don't agree

            if not a: # both differ from parent

                r = repo.ui.prompt(

                    _(" conflicting flags for %s\n"

                      "(n)one, e(x)ec or sym(l)ink?") % f, "[nxl]", "n")

                return r != "n" and r or ''

            if m == a:

                return n # changed from m to n

            return m # changed from n to m

        if m and m != a: # changed from a to m

            return m

        if n and n != a: # changed from a to n

            return n

        return '' # flag was cleared

    def act(msg, m, f, *args):

        repo.ui.debug(" %s: %s -> %s\n" % (f, msg, m))

        action.append((f, m) + args)

    if pa and not (backwards or overwrite):

        copy, diverge = copies.copies(repo, p1, p2, pa)

        copied = dict.fromkeys(copy.values())

        for of, fl in diverge.items():

            act("divergent renames", "dr", of, fl)

    # Compare manifests

    for f, n in m1.iteritems():

        if partial and not partial(f):

            continue

        if f in m2:

            if overwrite or backwards:

                rflags = m2.flags(f)

            else:

                rflags = fmerge(f)

            # are files different?

            if n != m2[f]:

                a = ma.get(f, nullid)

                # are we clobbering?

                if overwrite:

                    act("clobbering", "g", f, rflags)

                # or are we going back in time and clean?

                elif backwards and not n[20:]:

                    act("reverting", "g", f, rflags)

                # are both different from the ancestor?

                elif n != a and m2[f] != a:

                    act("versions differ", "m", f, f, f, rflags, False)

                # is remote's version newer?

                elif m2[f] != a:

                    act("remote is newer", "g", f, rflags)

                # local is newer, not overwrite, check mode bits

                elif m1.flags(f) != rflags:

                    act("update permissions", "e", f, rflags)

            # contents same, check mode bits

            elif m1.flags(f) != rflags:

                act("update permissions", "e", f, rflags)

        elif f in copied:

            continue

        elif f in copy:

            f2 = copy[f]

            if f2 not in m2: # directory rename

                act("remote renamed directory to " + f2, "d",

                    f, None, f2, m1.flags(f))

            elif f2 in m1: # case 2 A,B/B/B

                act("local copied to " + f2, "m",

                    f, f2, f, fmerge(f, f2, f2), False)

            else: # case 4,21 A/B/B

                act("local moved to " + f2, "m",

                    f, f2, f, fmerge(f, f2, f2), False)

        elif f in ma:

            if n != ma[f] and not overwrite:

                if repo.ui.prompt(

                    _(" local changed %s which remote deleted\n"

                      "use (c)hanged version or (d)elete?") % f,

                    _("[cd]"), _("c")) == _("d"):

                    act("prompt delete", "r", f)

            else:

                act("other deleted", "r", f)

        else:

            # file is created on branch or in working directory

            if (overwrite and n[20:] != "u") or (backwards and not n[20:]):

                act("remote deleted", "r", f)

    for f, n in m2.iteritems():

        if partial and not partial(f):

            continue

        if f in m1:

            continue

        if f in copied:

            continue

        if f in copy:

            f2 = copy[f]

            if f2 not in m1: # directory rename

                act("local renamed directory to " + f2, "d",

                    None, f, f2, m2.flags(f))

            elif f2 in m2: # rename case 1, A/A,B/A

                act("remote copied to " + f, "m",

                    f2, f, f, fmerge(f2, f, f2), False)

            else: # case 3,20 A/B/A

                act("remote moved to " + f, "m",

                    f2, f, f, fmerge(f2, f, f2), True)

        elif f in ma:

            if overwrite or backwards:

                act("recreating", "g", f, m2.flags(f))

            elif n != ma[f]:

                if repo.ui.prompt(

                    _("remote changed %s which local deleted\n"

                      "use (c)hanged version or leave (d)eleted?") % f,

                    _("[cd]"), _("c")) == _("c"):

                    act("prompt recreating", "g", f, m2.flags(f))

        else:

            act("remote created", "g", f, m2.flags(f))

    return action

def applyupdates(repo, action, wctx, mctx):

    "apply the merge action list to the working directory"

    updated, merged, removed, unresolved = 0, 0, 0, 0

    action.sort()

    # prescan for copy/renames

    for a in action:

        f, m = a[:2]

        if m == 'm': # merge

            f2, fd, flags, move = a[2:]

            if f != fd:

                repo.ui.debug(_("copying %s to %s\n") % (f, fd))

                repo.wwrite(fd, repo.wread(f), flags)

    audit_path = util.path_auditor(repo.root)

    for a in action:

        f, m = a[:2]

        if f and f[0] == "/":

            continue

        if m == "r": # remove

            repo.ui.note(_("removing %s\n") % f)

            audit_path(f)

            try:

                util.unlink(repo.wjoin(f))

            except OSError, inst:

                if inst.errno != errno.ENOENT:

                    repo.ui.warn(_("update failed to remove %s: %s!\n") %

                                 (f, inst.strerror))

            removed += 1

        elif m == "m": # merge

            f2, fd, flags, move = a[2:]

            r = filemerge.filemerge(repo, f, fd, f2, wctx, mctx)

            if r > 0:

                unresolved += 1

            else:

                if r is None:

                    updated += 1

                else:

                    merged += 1

            util.set_flags(repo.wjoin(fd), flags)

            if f != fd and move and util.lexists(repo.wjoin(f)):

                repo.ui.debug(_("removing %s\n") % f)

                os.unlink(repo.wjoin(f))

        elif m == "g": # get

            flags = a[2]

            repo.ui.note(_("getting %s\n") % f)

            t = mctx.filectx(f).data()

            repo.wwrite(f, t, flags)

            updated += 1

        elif m == "d": # directory rename

            f2, fd, flags = a[2:]

            if f:

                repo.ui.note(_("moving %s to %s\n") % (f, fd))

                t = wctx.filectx(f).data()

                repo.wwrite(fd, t, flags)

                util.unlink(repo.wjoin(f))

            if f2:

                repo.ui.note(_("getting %s to %s\n") % (f2, fd))

                t = mctx.filectx(f2).data()

                repo.wwrite(fd, t, flags)

            updated += 1

        elif m == "dr": # divergent renames

            fl = a[2]

            repo.ui.warn("warning: detected divergent renames of %s to:\n" % f)

            for nf in fl:

                repo.ui.warn(" %s\n" % nf)

        elif m == "e": # exec

            flags = a[2]

            util.set_flags(repo.wjoin(f), flags)

    return updated, merged, removed, unresolved

def recordupdates(repo, action, branchmerge):

    "record merge actions to the dirstate"

    for a in action:

        f, m = a[:2]

        if m == "r": # remove

            if branchmerge:

                repo.dirstate.remove(f)

            else:

                repo.dirstate.forget(f)

        elif m == "f": # forget

            repo.dirstate.forget(f)

        elif m in "ge": # get or exec change

            if branchmerge:

                repo.dirstate.normaldirty(f)

            else:

                repo.dirstate.normal(f)

        elif m == "m": # merge

            f2, fd, flag, move = a[2:]

            if branchmerge:

                # We've done a branch merge, mark this file as merged

                # so that we properly record the merger later

                repo.dirstate.merge(fd)

                if f != f2: # copy/rename

                    if move:

                        repo.dirstate.remove(f)

                    if f != fd:

                        repo.dirstate.copy(f, fd)

                    else:

                        repo.dirstate.copy(f2, fd)

            else:

                # We've update-merged a locally modified file, so

                # we set the dirstate to emulate a normal checkout

                # of that file some time in the past. Thus our

                # merge will appear as a normal local file

                # modification.

                repo.dirstate.normallookup(fd)

                if move:

                    repo.dirstate.forget(f)

        elif m == "d": # directory rename

            f2, fd, flag = a[2:]

            if not f2 and f not in repo.dirstate:

                # untracked file moved

                continue

            if branchmerge:

                repo.dirstate.add(fd)

                if f:

                    repo.dirstate.remove(f)

                    repo.dirstate.copy(f, fd)

                if f2:

                    repo.dirstate.copy(f2, fd)

            else:

                repo.dirstate.normal(fd)

                if f:

                    repo.dirstate.forget(f)

def update(repo, node, branchmerge, force, partial):

    """

    Perform a merge between the working directory and the given node

    branchmerge = whether to merge between branches

    force = whether to force branch merging or file overwriting

    partial = a function to filter file lists (dirstate not updated)

    """

    wlock = repo.wlock()

    try:

        wc = repo.workingctx()

        if node is None:

            # tip of current branch

            try:

                node = repo.branchtags()[wc.branch()]

            except KeyError:

                if wc.branch() == "default": # no default branch!

                    node = repo.lookup("tip") # update to tip

                else:

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

        overwrite = force and not branchmerge

        pl = wc.parents()

        p1, p2 = pl[0], repo.changectx(node)

        pa = p1.ancestor(p2)