# Patch transplanting extension for Mercurial

#

# Copyright 2006, 2007 Brendan Cully <brendan@kublai.com>

#

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

# GNU General Public License version 2 or any later version.

'''command to transplant changesets from another branch

This extension allows you to transplant patches from another branch.

Transplanted patches are recorded in .hg/transplant/transplants, as a

map from a changeset hash to its hash in the source repository.

'''

from mercurial.i18n import _

import os, tempfile

from mercurial import bundlerepo, cmdutil, hg, merge, match

from mercurial import patch, revlog, util, error

from mercurial import revset

class transplantentry(object):

    def __init__(self, lnode, rnode):

        self.lnode = lnode

        self.rnode = rnode

class transplants(object):

    def __init__(self, path=None, transplantfile=None, opener=None):

        self.path = path

        self.transplantfile = transplantfile

        self.opener = opener

        if not opener:

            self.opener = util.opener(self.path)

        self.transplants = {}

        self.dirty = False

        self.read()

    def read(self):

        abspath = os.path.join(self.path, self.transplantfile)

        if self.transplantfile and os.path.exists(abspath):

            for line in self.opener(self.transplantfile).read().splitlines():

                lnode, rnode = map(revlog.bin, line.split(':'))

                list = self.transplants.setdefault(rnode, [])

                list.append(transplantentry(lnode, rnode))

    def write(self):

        if self.dirty and self.transplantfile:

            if not os.path.isdir(self.path):

                os.mkdir(self.path)

            fp = self.opener(self.transplantfile, 'w')

            for list in self.transplants.itervalues():

                for t in list:

                    l, r = map(revlog.hex, (t.lnode, t.rnode))

                    fp.write(l + ':' + r + '\n')

            fp.close()

        self.dirty = False

    def get(self, rnode):

        return self.transplants.get(rnode) or []

    def set(self, lnode, rnode):

        list = self.transplants.setdefault(rnode, [])

        list.append(transplantentry(lnode, rnode))

        self.dirty = True

    def remove(self, transplant):

        list = self.transplants.get(transplant.rnode)

        if list:

            del list[list.index(transplant)]

            self.dirty = True

class transplanter(object):

    def __init__(self, ui, repo):

        self.ui = ui

        self.path = repo.join('transplant')

        self.opener = util.opener(self.path)

        self.transplants = transplants(self.path, 'transplants',

                                       opener=self.opener)

    def applied(self, repo, node, parent):

        '''returns True if a node is already an ancestor of parent

        or has already been transplanted'''

        if hasnode(repo, node):

            if node in repo.changelog.reachable(parent, stop=node):

                return True

        for t in self.transplants.get(node):

            # it might have been stripped

            if not hasnode(repo, t.lnode):

                self.transplants.remove(t)

                return False

            if t.lnode in repo.changelog.reachable(parent, stop=t.lnode):

                return True

        return False

    def apply(self, repo, source, revmap, merges, opts={}):

        '''apply the revisions in revmap one by one in revision order'''

        revs = sorted(revmap)

        p1, p2 = repo.dirstate.parents()

        pulls = []

        diffopts = patch.diffopts(self.ui, opts)

        diffopts.git = True

        lock = wlock = None

        try:

            wlock = repo.wlock()

            lock = repo.lock()

            for rev in revs:

                node = revmap[rev]

                revstr = '%s:%s' % (rev, revlog.short(node))

                if self.applied(repo, node, p1):

                    self.ui.warn(_('skipping already applied revision %s\n') %

                                 revstr)

                    continue

                parents = source.changelog.parents(node)

                if not opts.get('filter'):

                    # If the changeset parent is the same as the

                    # wdir's parent, just pull it.

                    if parents[0] == p1:

                        pulls.append(node)

                        p1 = node

                        continue

                    if pulls:

                        if source != repo:

                            repo.pull(source, heads=pulls)

                        merge.update(repo, pulls[-1], False, False, None)

                        p1, p2 = repo.dirstate.parents()

                        pulls = []

                domerge = False

                if node in merges:

                    # pulling all the merge revs at once would mean we

                    # couldn't transplant after the latest even if

                    # transplants before them fail.

                    domerge = True

                    if not hasnode(repo, node):

                        repo.pull(source, heads=[node])

                if parents[1] != revlog.nullid:

                    self.ui.note(_('skipping merge changeset %s:%s\n')

                                 % (rev, revlog.short(node)))

                    patchfile = None

                else:

                    fd, patchfile = tempfile.mkstemp(prefix='hg-transplant-')

                    fp = os.fdopen(fd, 'w')

                    gen = patch.diff(source, parents[0], node, opts=diffopts)

                    for chunk in gen:

                        fp.write(chunk)

                    fp.close()

                del revmap[rev]

                if patchfile or domerge:

                    try:

                        n = self.applyone(repo, node,

                                          source.changelog.read(node),

                                          patchfile, merge=domerge,

                                          log=opts.get('log'),

                                          filter=opts.get('filter'))

                        if n and domerge:

                            self.ui.status(_('%s merged at %s\n') % (revstr,

                                      revlog.short(n)))

                        elif n:

                            self.ui.status(_('%s transplanted to %s\n')

                                           % (revlog.short(node),

                                              revlog.short(n)))

                    finally:

                        if patchfile:

                            os.unlink(patchfile)

            if pulls:

                repo.pull(source, heads=pulls)

                merge.update(repo, pulls[-1], False, False, None)

        finally:

            self.saveseries(revmap, merges)

            self.transplants.write()

            lock.release()

            wlock.release()

    def filter(self, filter, changelog, patchfile):

        '''arbitrarily rewrite changeset before applying it'''

        self.ui.status(_('filtering %s\n') % patchfile)

        user, date, msg = (changelog[1], changelog[2], changelog[4])

        fd, headerfile = tempfile.mkstemp(prefix='hg-transplant-')

        fp = os.fdopen(fd, 'w')

        fp.write("# HG changeset patch\n")

        fp.write("# User %s\n" % user)

        fp.write("# Date %d %d\n" % date)

        fp.write(msg + '\n')

        fp.close()

        try:

            util.system('%s %s %s' % (filter, util.shellquote(headerfile),

                                   util.shellquote(patchfile)),

                        environ={'HGUSER': changelog[1]},

                        onerr=util.Abort, errprefix=_('filter failed'))

            user, date, msg = self.parselog(file(headerfile))[1:4]

        finally:

            os.unlink(headerfile)

        return (user, date, msg)

    def applyone(self, repo, node, cl, patchfile, merge=False, log=False,

                 filter=None):

        '''apply the patch in patchfile to the repository as a transplant'''

        (manifest, user, (time, timezone), files, message) = cl[:5]

        date = "%d %d" % (time, timezone)

        extra = {'transplant_source': node}

        if filter:

            (user, date, message) = self.filter(filter, cl, patchfile)

        if log:

            # we don't translate messages inserted into commits

            message += '\n(transplanted from %s)' % revlog.hex(node)

        self.ui.status(_('applying %s\n') % revlog.short(node))

        self.ui.note('%s %s\n%s\n' % (user, date, message))

        if not patchfile and not merge:

            raise util.Abort(_('can only omit patchfile if merging'))

        if patchfile:

            try:

                files = {}

                try:

                    patch.patch(patchfile, self.ui, cwd=repo.root,

                                files=files, eolmode=None)

                    if not files:

                        self.ui.warn(_('%s: empty changeset')

                                     % revlog.hex(node))

                        return None

                finally:

                    files = cmdutil.updatedir(self.ui, repo, files)

            except Exception, inst:

                seriespath = os.path.join(self.path, 'series')

                if os.path.exists(seriespath):

                    os.unlink(seriespath)

                p1 = repo.dirstate.parents()[0]

                p2 = node

                self.log(user, date, message, p1, p2, merge=merge)

                self.ui.write(str(inst) + '\n')

                raise util.Abort(_('fix up the merge and run '

                                   'hg transplant --continue'))

        else:

            files = None

        if merge:

            p1, p2 = repo.dirstate.parents()

            repo.dirstate.setparents(p1, node)

            m = match.always(repo.root, '')

        else:

            m = match.exact(repo.root, '', files)

        n = repo.commit(message, user, date, extra=extra, match=m)

        if not n:

            # Crash here to prevent an unclear crash later, in

            # transplants.write().  This can happen if patch.patch()

            # does nothing but claims success or if repo.status() fails

            # to report changes done by patch.patch().  These both

            # appear to be bugs in other parts of Mercurial, but dying

            # here, as soon as we can detect the problem, is preferable

            # to silently dropping changesets on the floor.

            raise RuntimeError('nothing committed after transplant')

        if not merge:

            self.transplants.set(n, node)

        return n

    def resume(self, repo, source, opts=None):

        '''recover last transaction and apply remaining changesets'''

        if os.path.exists(os.path.join(self.path, 'journal')):

            n, node = self.recover(repo)

            self.ui.status(_('%s transplanted as %s\n') % (revlog.short(node),

                                                           revlog.short(n)))

        seriespath = os.path.join(self.path, 'series')

        if not os.path.exists(seriespath):

            self.transplants.write()

            return

        nodes, merges = self.readseries()

        revmap = {}

        for n in nodes:

            revmap[source.changelog.rev(n)] = n

        os.unlink(seriespath)

        self.apply(repo, source, revmap, merges, opts)

    def recover(self, repo):

        '''commit working directory using journal metadata'''

        node, user, date, message, parents = self.readlog()

        merge = len(parents) == 2

        if not user or not date or not message or not parents[0]:

            raise util.Abort(_('transplant log file is corrupt'))

        extra = {'transplant_source': node}

        wlock = repo.wlock()

        try:

            p1, p2 = repo.dirstate.parents()

            if p1 != parents[0]:

                raise util.Abort(

                    _('working dir not at transplant parent %s') %

                                 revlog.hex(parents[0]))

            if merge:

                repo.dirstate.setparents(p1, parents[1])

            n = repo.commit(message, user, date, extra=extra)

            if not n:

                raise util.Abort(_('commit failed'))

            if not merge:

                self.transplants.set(n, node)

            self.unlog()

            return n, node

        finally:

            wlock.release()

    def readseries(self):

        nodes = []

        merges = []

        cur = nodes

        for line in self.opener('series').read().splitlines():

            if line.startswith('# Merges'):

                cur = merges

                continue

            cur.append(revlog.bin(line))

        return (nodes, merges)

    def saveseries(self, revmap, merges):

        if not revmap:

            return

        if not os.path.isdir(self.path):

            os.mkdir(self.path)

        series = self.opener('series', 'w')

        for rev in sorted(revmap):

            series.write(revlog.hex(revmap[rev]) + '\n')

        if merges:

            series.write('# Merges\n')

            for m in merges:

                series.write(revlog.hex(m) + '\n')

        series.close()

    def parselog(self, fp):

        parents = []

        message = []

        node = revlog.nullid

        inmsg = False

        for line in fp.read().splitlines():

            if inmsg:

                message.append(line)

            elif line.startswith('# User '):

                user = line[7:]

            elif line.startswith('# Date '):

                date = line[7:]

            elif line.startswith('# Node ID '):

                node = revlog.bin(line[10:])

            elif line.startswith('# Parent '):

                parents.append(revlog.bin(line[9:]))

            elif not line.startswith('# '):

                inmsg = True

                message.append(line)

        return (node, user, date, '\n'.join(message), parents)

    def log(self, user, date, message, p1, p2, merge=False):

        '''journal changelog metadata for later recover'''

        if not os.path.isdir(self.path):

            os.mkdir(self.path)

        fp = self.opener('journal', 'w')

        fp.write('# User %s\n' % user)

        fp.write('# Date %s\n' % date)

        fp.write('# Node ID %s\n' % revlog.hex(p2))

        fp.write('# Parent ' + revlog.hex(p1) + '\n')

        if merge:

            fp.write('# Parent ' + revlog.hex(p2) + '\n')

        fp.write(message.rstrip() + '\n')

        fp.close()

    def readlog(self):

        return self.parselog(self.opener('journal'))

    def unlog(self):

        '''remove changelog journal'''

        absdst = os.path.join(self.path, 'journal')

        if os.path.exists(absdst):

            os.unlink(absdst)

    def transplantfilter(self, repo, source, root):

        def matchfn(node):

            if self.applied(repo, node, root):

                return False

            if source.changelog.parents(node)[1] != revlog.nullid:

                return False

            extra = source.changelog.read(node)[5]

            cnode = extra.get('transplant_source')

            if cnode and self.applied(repo, cnode, root):

                return False

            return True

        return matchfn

def hasnode(repo, node):

    try:

        return repo.changelog.rev(node) != None

    except error.RevlogError:

        return False

def browserevs(ui, repo, nodes, opts):

    '''interactively transplant changesets'''

    def browsehelp(ui):

        ui.write(_('y: transplant this changeset\n'

                   'n: skip this changeset\n'

                   'm: merge at this changeset\n'

                   'p: show patch\n'

                   'c: commit selected changesets\n'

                   'q: cancel transplant\n'

                   '?: show this help\n'))

    displayer = cmdutil.show_changeset(ui, repo, opts)

    transplants = []

    merges = []

    for node in nodes:

        displayer.show(repo[node])

        action = None

        while not action:

            action = ui.prompt(_('apply changeset? [ynmpcq?]:'))

            if action == '?':

                browsehelp(ui)

                action = None

            elif action == 'p':

                parent = repo.changelog.parents(node)[0]

                for chunk in patch.diff(repo, parent, node):

                    ui.write(chunk)

                action = None

            elif action not in ('y', 'n', 'm', 'c', 'q'):

                ui.write(_('no such option\n'))

                action = None

        if action == 'y':

            transplants.append(node)

        elif action == 'm':

            merges.append(node)

        elif action == 'c':

            break

        elif action == 'q':

            transplants = ()

            merges = ()

            break

    displayer.close()

    return (transplants, merges)

def transplant(ui, repo, *revs, **opts):

    '''transplant changesets from another branch

    Selected changesets will be applied on top of the current working

    directory with the log of the original changeset. If --log is

    specified, log messages will have a comment appended of the form::

      (transplanted from CHANGESETHASH)

    You can rewrite the changelog message with the --filter option.

    Its argument will be invoked with the current changelog message as

    $1 and the patch as $2.

    If --source/-s is specified, selects changesets from the named

    repository. If --branch/-b is specified, selects changesets from

    the branch holding the named revision, up to that revision. If

    --all/-a is specified, all changesets on the branch will be

    transplanted, otherwise you will be prompted to select the

    changesets you want.

    :hg:`transplant --branch REVISION --all` will rebase the selected

    branch (up to the named revision) onto your current working

    directory.

    You can optionally mark selected transplanted changesets as merge

    changesets. You will not be prompted to transplant any ancestors

    of a merged transplant, and you can merge descendants of them

    normally instead of transplanting them.

    If no merges or revisions are provided, :hg:`transplant` will

    start an interactive changeset browser.

    If a changeset application fails, you can fix the merge by hand

    and then resume where you left off by calling :hg:`transplant

    --continue/-c`.

    '''

    def incwalk(repo, incoming, branches, match=util.always):

        if not branches:

            branches = None

        for node in repo.changelog.nodesbetween(incoming, branches)[0]:

            if match(node):

                yield node

    def transplantwalk(repo, root, branches, match=util.always):

        if not branches:

            branches = repo.heads()

        ancestors = []

        for branch in branches:

            ancestors.append(repo.changelog.ancestor(root, branch))

        for node in repo.changelog.nodesbetween(ancestors, branches)[0]:

            if match(node):

                yield node

    def checkopts(opts, revs):

        if opts.get('continue'):

            if opts.get('branch') or opts.get('all') or opts.get('merge'):

                raise util.Abort(_('--continue is incompatible with '

                                   'branch, all or merge'))

            return

        if not (opts.get('source') or revs or

                opts.get('merge') or opts.get('branch')):

            raise util.Abort(_('no source URL, branch tag or revision '

                               'list provided'))

        if opts.get('all'):

            if not opts.get('branch'):

                raise util.Abort(_('--all requires a branch revision'))

            if revs:

                raise util.Abort(_('--all is incompatible with a '

                                   'revision list'))

    checkopts(opts, revs)

    if not opts.get('log'):

        opts['log'] = ui.config('transplant', 'log')

    if not opts.get('filter'):

        opts['filter'] = ui.config('transplant', 'filter')

    tp = transplanter(ui, repo)