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

#

# Copyright 2006 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 *

from i18n import gettext as _

from demandload import *

demandload(globals(), "util os tempfile")

def merge3(repo, fn, my, other, p1, p2):

    """perform a 3-way merge in the working directory"""

    def temp(prefix, node):

        pre = "%s~%s." % (os.path.basename(fn), prefix)

        (fd, name) = tempfile.mkstemp(prefix=pre)

        f = os.fdopen(fd, "wb")

        repo.wwrite(fn, fl.read(node), f)

        f.close()

        return name

    fl = repo.file(fn)

    base = fl.ancestor(my, other)

    a = repo.wjoin(fn)

    b = temp("base", base)

    c = temp("other", other)

    repo.ui.note(_("resolving %s\n") % fn)

    repo.ui.debug(_("file %s: my %s other %s ancestor %s\n") %

                          (fn, short(my), short(other), short(base)))

    cmd = (os.environ.get("HGMERGE") or repo.ui.config("ui", "merge")

           or "hgmerge")

    r = util.system('%s "%s" "%s" "%s"' % (cmd, a, b, c), cwd=repo.root,

                    environ={'HG_FILE': fn,

                             'HG_MY_NODE': p1,

                             'HG_OTHER_NODE': p2,

                             'HG_FILE_MY_NODE': hex(my),

                             'HG_FILE_OTHER_NODE': hex(other),

                             'HG_FILE_BASE_NODE': hex(base)})

    if r:

        repo.ui.warn(_("merging %s failed!\n") % fn)

    os.unlink(b)

    os.unlink(c)

    return r

def update(repo, node, branchmerge=False, force=False, partial=None,

           wlock=None, show_stats=True, remind=True):

    overwrite = force and not branchmerge

    forcemerge = force and branchmerge

    if not wlock:

        wlock = repo.wlock()

    ### check phase

    pl = repo.dirstate.parents()

    if not overwrite and pl[1] != nullid:

        raise util.Abort(_("outstanding uncommitted merges"))

    p1, p2 = pl[0], node

    pa = repo.changelog.ancestor(p1, p2)

    # is there a linear path from p1 to p2?

    linear_path = (pa == p1 or pa == p2)

    if branchmerge and linear_path:

        raise util.Abort(_("there is nothing to merge, just use "

                           "'hg update' or look at 'hg heads'"))

    if not overwrite and not linear_path and not branchmerge:

        raise util.Abort(_("update spans branches, use 'hg merge' "

                           "or 'hg update -C' to lose changes"))

    modified, added, removed, deleted, unknown = repo.status()[:5]

    if branchmerge and not forcemerge:

        if modified or added or removed:

            raise util.Abort(_("outstanding uncommitted changes"))

    m1n = repo.changelog.read(p1)[0]

    m2n = repo.changelog.read(p2)[0]

    man = repo.manifest.ancestor(m1n, m2n)

    m1 = repo.manifest.read(m1n)

    m2 = repo.manifest.read(m2n).copy()

    ma = repo.manifest.read(man)

    if not force:

        for f in unknown:

            if f in m2:

                t1 = repo.wread(f)

                t2 = repo.file(f).read(m2[f])

                if cmp(t1, t2) != 0:

                    raise util.Abort(_("'%s' already exists in the working"

                                       " dir and differs from remote") % f)

    # resolve the manifest to determine which files

    # we care about merging

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

    repo.ui.debug(_(" overwrite %s branchmerge %s partial %s linear %s\n") %

                  (overwrite, branchmerge, partial and True or False, linear_path))

    repo.ui.debug(_(" ancestor %s local %s remote %s\n") %

                  (short(man), short(m1n), short(m2n)))

    merge = {}

    get = {}

    remove = []

    # construct a working dir manifest

    mw = m1.copy()

    umap = dict.fromkeys(unknown)

    for f in added + modified + unknown:

        mw[f] = ""

        mw.set(f, util.is_exec(repo.wjoin(f), mw.execf(f)))

    for f in deleted + removed:

        if f in mw:

            del mw[f]

        # 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 not partial and linear_path and f not in m2:

            repo.dirstate.forget((f,))

    # Compare manifests

    for f, n in mw.iteritems():

        if partial and not partial(f):

            continue

        if f in m2:

            s = 0

            # is the wfile new since m1, and match m2?

            if f not in m1:

                t1 = repo.wread(f)

                t2 = repo.file(f).read(m2[f])

                if cmp(t1, t2) == 0:

                    n = m2[f]

                del t1, t2

            # are files different?

            if n != m2[f]:

                a = ma.get(f, nullid)

                # are both different from the ancestor?

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

                    repo.ui.debug(_(" %s versions differ, resolve\n") % f)

                    # merge executable bits

                    # "if we changed or they changed, change in merge"

                    a, b, c = ma.execf(f), mw.execf(f), m2.execf(f)

                    mode = ((a^b) | (a^c)) ^ a

                    merge[f] = (mode, m1.get(f, nullid), m2[f])

                    s = 1

                # are we clobbering?

                # is remote's version newer?

                # or are we going back in time?

                elif overwrite or m2[f] != a or (p2 == pa and mw[f] == m1[f]):

                    repo.ui.debug(_(" remote %s is newer, get\n") % f)

                    get[f] = (m2.execf(f), m2[f])

                    s = 1

            elif f in umap or f in added:

                # this unknown file is the same as the checkout

                # we need to reset the dirstate if the file was added

                get[f] = (m2.execf(f), m2[f])

            if not s and mw.execf(f) != m2.execf(f):

                if overwrite:

                    repo.ui.debug(_(" updating permissions for %s\n") % f)

                    util.set_exec(repo.wjoin(f), m2.execf(f))

                else:

                    a, b, c = ma.execf(f), mw.execf(f), m2.execf(f)

                    mode = ((a^b) | (a^c)) ^ a

                    if mode != b:

                        repo.ui.debug(_(" updating permissions for %s\n")

                                      % f)

                        util.set_exec(repo.wjoin(f), mode)

            del m2[f]

        elif f in ma:

            if n != ma[f]:

                r = _("d")

                if not overwrite and (linear_path or branchmerge):

                    r = repo.ui.prompt(

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

                         _("(k)eep or (d)elete?"), _("[kd]"), _("k"))

                if r == _("d"):

                    remove.append(f)

            else:

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

                remove.append(f) # other deleted it

        else:

            # file is created on branch or in working directory

            if overwrite and f not in umap:

                repo.ui.debug(_("remote deleted %s, clobbering\n") % f)

                remove.append(f)

            elif n == m1.get(f, nullid): # same as parent

                if p2 == pa: # going backwards?

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

                    remove.append(f)

                else:

                    repo.ui.debug(_("local modified %s, keeping\n") % f)

            else:

                repo.ui.debug(_("working dir created %s, keeping\n") % f)

    for f, n in m2.iteritems():

        if partial and not partial(f):

            continue

        if f[0] == "/":

            continue

        if f in ma and n != ma[f]:

            r = _("k")

            if not overwrite and (linear_path or branchmerge):

                r = repo.ui.prompt(

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

                     _("(k)eep or (d)elete?"), _("[kd]"), _("k"))

            if r == _("k"):

                get[f] = (m2.execf(f), n)

        elif f not in ma:

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

            get[f] = (m2.execf(f), n)

        else:

            if overwrite or p2 == pa: # going backwards?

                repo.ui.debug(_("local deleted %s, recreating\n") % f)

                get[f] = (m2.execf(f), n)

            else:

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

    del mw, m1, m2, ma

    if overwrite:

        for f in merge:

            get[f] = merge[f][:2]

        merge = {}

    if linear_path or overwrite:

        # we don't need to do any magic, just jump to the new rev

        p1, p2 = p2, nullid

    xp1 = hex(p1)

    xp2 = hex(p2)

    if p2 == nullid: xxp2 = ''

    else: xxp2 = xp2

    repo.hook('preupdate', throw=True, parent1=xp1, parent2=xxp2)

    # get the files we don't need to change

    files = get.keys()

    files.sort()

    for f in files:

        flag, node = get[f]

        if f[0] == "/":

            continue

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

        t = repo.file(f).read(node)

        repo.wwrite(f, t)

        util.set_exec(repo.wjoin(f), flag)

        if not partial:

            if branchmerge:

                repo.dirstate.update([f], 'n', st_mtime=-1)

            else:

                repo.dirstate.update([f], 'n')

    # merge the tricky bits

    unresolved = []

    files = merge.keys()

    files.sort()

    for f in files:

        repo.ui.status(_("merging %s\n") % f)

        flag, my, other = merge[f]

        ret = merge3(repo, f, my, other, xp1, xp2)

        if ret:

            unresolved.append(f)

        util.set_exec(repo.wjoin(f), flag)

        if not partial:

            if branchmerge:

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

                # so that we properly record the merger later

                repo.dirstate.update([f], 'm')

            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.

                f_len = len(repo.file(f).read(other))

                repo.dirstate.update([f], 'n', st_size=f_len, st_mtime=-1)

    remove.sort()

    for f in remove:

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

        util.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))

    if not partial:

        if branchmerge:

            repo.dirstate.update(remove, 'r')

        else:

            repo.dirstate.forget(remove)

    if not partial:

        repo.dirstate.setparents(p1, p2)

    if show_stats:

        stats = ((len(get), _("updated")),

                 (len(merge) - len(unresolved), _("merged")),

                 (len(remove), _("removed")),

                 (len(unresolved), _("unresolved")))

        note = ", ".join([_("%d files %s") % s for s in stats])

        repo.ui.status("%s\n" % note)

    if not partial:

        if branchmerge:

            if unresolved:

                repo.ui.status(_("There are unresolved merges,"

                                " you can redo the full merge using:\n"

                                "  hg update -C %s\n"

                                "  hg merge %s\n"

                                % (repo.changelog.rev(p1),

                                    repo.changelog.rev(p2))))

            elif remind:

                repo.ui.status(_("(branch merge, don't forget to commit)\n"))

        elif unresolved:

            repo.ui.status(_("There are unresolved merges with"

                             " locally modified files.\n"))

    repo.hook('update', parent1=xp1, parent2=xxp2, error=len(unresolved))

    return len(unresolved)