# 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, hex, bin

from i18n import _

import errno, util, os, filemerge, copies, shutil

class mergestate(object):

    '''track 3-way merge state of individual files'''

    def __init__(self, repo):

        self._repo = repo

        self._read()

    def reset(self, node):

        self._state = {}

        self._local = node

        shutil.rmtree(self._repo.join("merge"), True)

    def _read(self):

        self._state = {}

        try:

            localnode = None

            f = self._repo.opener("merge/state")

            for i, l in enumerate(f):

                if i == 0:

                    localnode = l[:-1]

                else:

                    bits = l[:-1].split("\0")

                    self._state[bits[0]] = bits[1:]

            self._local = bin(localnode)

        except IOError, err:

            if err.errno != errno.ENOENT:

                raise

    def _write(self):

        f = self._repo.opener("merge/state", "w")

        f.write(hex(self._local) + "\n")

        for d, v in self._state.items():

            f.write("\0".join([d] + v) + "\n")

    def add(self, fcl, fco, fca, fd, flags):

        hash = util.sha1(fcl.path()).hexdigest()

        self._repo.opener("merge/" + hash, "w").write(fcl.data())

        self._state[fd] = ['u', hash, fcl.path(), fca.path(),

                           hex(fca.filenode()), fco.path(), flags]

        self._write()

    def __contains__(self, dfile):

        return dfile in self._state

    def __getitem__(self, dfile):

        return self._state[dfile][0]

    def __iter__(self):

        l = self._state.keys()

        l.sort()

        for f in l:

            yield f

    def mark(self, dfile, state):

        self._state[dfile][0] = state

        self._write()

    def resolve(self, dfile, wctx, octx):

        if self[dfile] == 'r':

            return 0

        state, hash, lfile, afile, anode, ofile, flags = self._state[dfile]

        f = self._repo.opener("merge/" + hash)

        self._repo.wwrite(dfile, f.read(), flags)

        fcd = wctx[dfile]

        fco = octx[ofile]

        fca = self._repo.filectx(afile, fileid=anode)

        r = filemerge.filemerge(self._repo, self._local, lfile, fcd, fco, fca)

        if not r:

            self.mark(dfile, 'r')

        return r

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):

        if repo.ui.configbool("merge", "followcopies", True):

            dirs = repo.ui.configbool("merge", "followdirs", True)

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

        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

    ms = mergestate(repo)

    ms.reset(wctx.parents()[0].node())

    moves = []

    # prescan for merges

    for a in action:

        f, m = a[:2]

        if m == 'm': # merge

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

            repo.ui.debug(_("preserving %s for resolve of %s\n") % (f, fd))

            fcl = wctx[f]

            fco = mctx[f2]

            fca = fcl.ancestor(fco) or repo.filectx(f, fileid=nullrev)

            ms.add(fcl, fco, fca, fd, flags)

            if f != fd and move:

                moves.append(f)

    # remove renamed files after safely stored

    for f in moves:

        if util.lexists(repo.wjoin(f)):

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

            os.unlink(repo.wjoin(f))

    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 = ms.resolve(fd, wctx, mctx)

            if r > 0:

                unresolved += 1

            else:

                if r is None:

                    updated += 1

                else:

                    merged += 1

        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