# histedit.py - interactive history editing for mercurial

#

# Copyright 2009 Augie Fackler <raf@durin42.com>

#

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

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

"""interactive history editing

With this extension installed, Mercurial gains one new command: histedit. Usage

is as follows, assuming the following history::

 @  3[tip]   7c2fd3b9020c   2009-04-27 18:04 -0500   durin42

 |    Add delta

 |

 o  2   030b686bedc4   2009-04-27 18:04 -0500   durin42

 |    Add gamma

 |

 o  1   c561b4e977df   2009-04-27 18:04 -0500   durin42

 |    Add beta

 |

 o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42

      Add alpha

If you were to run ``hg histedit c561b4e977df``, you would see the following

file open in your editor::

 pick c561b4e977df Add beta

 pick 030b686bedc4 Add gamma

 pick 7c2fd3b9020c Add delta

 # Edit history between 633536316234 and 7c2fd3b9020c

 #

 # Commands:

 #  p, pick = use commit

 #  e, edit = use commit, but stop for amending

 #  f, fold = use commit, but fold into previous commit (combines N and N-1)

 #  d, drop = remove commit from history

 #  m, mess = edit message without changing commit content

 #

In this file, lines beginning with ``#`` are ignored. You must specify a rule

for each revision in your history. For example, if you had meant to add gamma

before beta, and then wanted to add delta in the same revision as beta, you

would reorganize the file to look like this::

 pick 030b686bedc4 Add gamma

 pick c561b4e977df Add beta

 fold 7c2fd3b9020c Add delta

 # Edit history between 633536316234 and 7c2fd3b9020c

 #

 # Commands:

 #  p, pick = use commit

 #  e, edit = use commit, but stop for amending

 #  f, fold = use commit, but fold into previous commit (combines N and N-1)

 #  d, drop = remove commit from history

 #  m, mess = edit message without changing commit content

 #

At which point you close the editor and ``histedit`` starts working. When you

specify a ``fold`` operation, ``histedit`` will open an editor when it folds

those revisions together, offering you a chance to clean up the commit message::

 Add beta

 ***

 Add delta

Edit the commit message to your liking, then close the editor. For

this example, let's assume that the commit message was changed to

``Add beta and delta.`` After histedit has run and had a chance to

remove any old or temporary revisions it needed, the history looks

like this::

 @  2[tip]   989b4d060121   2009-04-27 18:04 -0500   durin42

 |    Add beta and delta.

 |

 o  1   081603921c3f   2009-04-27 18:04 -0500   durin42

 |    Add gamma

 |

 o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42

      Add alpha

Note that ``histedit`` does *not* remove any revisions (even its own temporary

ones) until after it has completed all the editing operations, so it will

probably perform several strip operations when it's done. For the above example,

it had to run strip twice. Strip can be slow depending on a variety of factors,

so you might need to be a little patient. You can choose to keep the original

revisions by passing the ``--keep`` flag.

The ``edit`` operation will drop you back to a command prompt,

allowing you to edit files freely, or even use ``hg record`` to commit

some changes as a separate commit. When you're done, any remaining

uncommitted changes will be committed as well. When done, run ``hg

histedit --continue`` to finish this step. You'll be prompted for a

new commit message, but the default commit message will be the

original message for the ``edit`` ed revision.

The ``message`` operation will give you a chance to revise a commit

message without changing the contents. It's a shortcut for doing

``edit`` immediately followed by `hg histedit --continue``.

If ``histedit`` encounters a conflict when moving a revision (while

handling ``pick`` or ``fold``), it'll stop in a similar manner to

``edit`` with the difference that it won't prompt you for a commit

message when done. If you decide at this point that you don't like how

much work it will be to rearrange history, or that you made a mistake,

you can use ``hg histedit --abort`` to abandon the new changes you

have made and return to the state before you attempted to edit your

history.

If we clone the example repository above and add three more changes, such that

we have the following history::

   @  6[tip]   038383181893   2009-04-27 18:04 -0500   stefan

   |    Add theta

   |

   o  5   140988835471   2009-04-27 18:04 -0500   stefan

   |    Add eta

   |

   o  4   122930637314   2009-04-27 18:04 -0500   stefan

   |    Add zeta

   |

   o  3   836302820282   2009-04-27 18:04 -0500   stefan

   |    Add epsilon

   |

   o  2   989b4d060121   2009-04-27 18:04 -0500   durin42

   |    Add beta and delta.

   |

   o  1   081603921c3f   2009-04-27 18:04 -0500   durin42

   |    Add gamma

   |

   o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42

        Add alpha

If you run ``hg histedit --outgoing`` on the clone then it is the same

as running ``hg histedit 836302820282``. If you need plan to push to a

repository that Mercurial does not detect to be related to the source

repo, you can add a ``--force`` option.

"""

try:

    import cPickle as pickle

except ImportError:

    import pickle

import tempfile

import os

from mercurial import bookmarks

from mercurial import cmdutil

from mercurial import discovery

from mercurial import error

from mercurial import hg

from mercurial import lock as lockmod

from mercurial import node

from mercurial import patch

from mercurial import repair

from mercurial import scmutil

from mercurial import util

from mercurial.i18n import _

cmdtable = {}

command = cmdutil.command(cmdtable)

testedwith = 'internal'

# i18n: command names and abbreviations must remain untranslated

editcomment = _("""# Edit history between %s and %s

#

# Commands:

#  p, pick = use commit

#  e, edit = use commit, but stop for amending

#  f, fold = use commit, but fold into previous commit (combines N and N-1)

#  d, drop = remove commit from history

#  m, mess = edit message without changing commit content

#

""")

def foldchanges(ui, repo, node1, node2, opts):

    """Produce a new changeset that represents the diff from node1 to node2."""

    try:

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

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

        diffopts = patch.diffopts(ui, opts)

        diffopts.git = True

        diffopts.ignorews = False

        diffopts.ignorewsamount = False

        diffopts.ignoreblanklines = False

        gen = patch.diff(repo, node1, node2, opts=diffopts)

        for chunk in gen:

            fp.write(chunk)

        fp.close()

        files = set()

        patch.patch(ui, repo, patchfile, files=files, eolmode=None)

    finally:

        os.unlink(patchfile)

    return files

def between(repo, old, new, keep):

    """select and validate the set of revision to edit

    When keep is false, the specified set can't have children."""

    revs = [old]

    current = old

    while current != new:

        ctx = repo[current]

        if not keep and len(ctx.children()) > 1:

            raise util.Abort(_('cannot edit history that would orphan nodes'))

        if len(ctx.parents()) != 1 and ctx.parents()[1] != node.nullid:

            raise util.Abort(_("can't edit history with merges"))

        if not ctx.children():

            current = new

        else:

            current = ctx.children()[0].node()

            revs.append(current)

    if len(repo[current].children()) and not keep:

        raise util.Abort(_('cannot edit history that would orphan nodes'))

    return revs

def pick(ui, repo, ctx, ha, opts):

    oldctx = repo[ha]

    if oldctx.parents()[0] == ctx:

        ui.debug('node %s unchanged\n' % ha)

        return oldctx, [], [], []

    hg.update(repo, ctx.node())

    try:

        files = foldchanges(ui, repo, oldctx.p1().node() , ha, opts)

        if not files:

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

                         % node.hex(ha))

            return ctx, [], [], []

    except Exception:

        raise util.Abort(_('Fix up the change and run '

                           'hg histedit --continue'))

    n = repo.commit(text=oldctx.description(), user=oldctx.user(),

                    date=oldctx.date(), extra=oldctx.extra())

    return repo[n], [n], [oldctx.node()], []

def edit(ui, repo, ctx, ha, opts):

    oldctx = repo[ha]

    hg.update(repo, ctx.node())

    try:

        foldchanges(ui, repo, oldctx.p1().node() , ha, opts)

    except Exception:

        pass

    raise util.Abort(_('Make changes as needed, you may commit or record as '

                       'needed now.\nWhen you are finished, run hg'

                       ' histedit --continue to resume.'))

def fold(ui, repo, ctx, ha, opts):

    oldctx = repo[ha]

    hg.update(repo, ctx.node())

    try:

        files = foldchanges(ui, repo, oldctx.p1().node() , ha, opts)

        if not files:

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

                         % node.hex(ha))

            return ctx, [], [], []

    except Exception:

        raise util.Abort(_('Fix up the change and run '

                           'hg histedit --continue'))

    n = repo.commit(text='fold-temp-revision %s' % ha, user=oldctx.user(),

                    date=oldctx.date(), extra=oldctx.extra())

    return finishfold(ui, repo, ctx, oldctx, n, opts, [])

def finishfold(ui, repo, ctx, oldctx, newnode, opts, internalchanges):

    parent = ctx.parents()[0].node()

    hg.update(repo, parent)

    foldchanges(ui, repo, parent, newnode, opts)

    newmessage = '\n***\n'.join(

        [ctx.description()] +

        [repo[r].description() for r in internalchanges] +

        [oldctx.description()]) + '\n'

    # If the changesets are from the same author, keep it.

    if ctx.user() == oldctx.user():

        username = ctx.user()

    else:

        username = ui.username()

    newmessage = ui.edit(newmessage, username)

    n = repo.commit(text=newmessage, user=username,

                    date=max(ctx.date(), oldctx.date()), extra=oldctx.extra())

    return repo[n], [n], [oldctx.node(), ctx.node()], [newnode]

def drop(ui, repo, ctx, ha, opts):

    return ctx, [], [repo[ha].node()], []

def message(ui, repo, ctx, ha, opts):

    oldctx = repo[ha]

    hg.update(repo, ctx.node())

    try:

        foldchanges(ui, repo, oldctx.p1().node() , ha, opts)

    except Exception:

        raise util.Abort(_('Fix up the change and run '

                           'hg histedit --continue'))

    message = oldctx.description() + '\n'

    message = ui.edit(message, ui.username())

    new = repo.commit(text=message, user=oldctx.user(), date=oldctx.date(),

                      extra=oldctx.extra())

    newctx = repo[new]

    if oldctx.node() != newctx.node():

        return newctx, [new], [oldctx.node()], []

    # We didn't make an edit, so just indicate no replaced nodes

    return newctx, [new], [], []

def makedesc(c):

    summary = ''

    if c.description():

        summary = c.description().splitlines()[0]

    line = 'pick %s %d %s' % (c.hex()[:12], c.rev(), summary)

    return line[:80]  # trim to 80 chars so it's not stupidly wide in my editor

actiontable = {'p': pick,

               'pick': pick,

               'e': edit,

               'edit': edit,

               'f': fold,

               'fold': fold,

               'd': drop,

               'drop': drop,

               'm': message,

               'mess': message,

               }

@command('histedit',

    [('', 'commands', '',

      _('Read history edits from the specified file.')),

     ('c', 'continue', False, _('continue an edit already in progress')),

     ('k', 'keep', False,

      _("don't strip old nodes after edit is complete")),

     ('', 'abort', False, _('abort an edit in progress')),

     ('o', 'outgoing', False, _('changesets not found in destination')),

     ('f', 'force', False,

      _('force outgoing even for unrelated repositories')),

     ('r', 'rev', [], _('first revision to be edited'))],

     _("[PARENT]"))

def histedit(ui, repo, *parent, **opts):

    """interactively edit changeset history

    """

    # TODO only abort if we try and histedit mq patches, not just

    # blanket if mq patches are applied somewhere

    mq = getattr(repo, 'mq', None)

    if mq and mq.applied:

        raise util.Abort(_('source has mq patches applied'))

    parent = list(parent) + opts.get('rev', [])

    if opts.get('outgoing'):

        if len(parent) > 1:

            raise util.Abort(

                _('only one repo argument allowed with --outgoing'))

        elif parent:

            parent = parent[0]

        dest = ui.expandpath(parent or 'default-push', parent or 'default')

        dest, revs = hg.parseurl(dest, None)[:2]

        ui.status(_('comparing with %s\n') % util.hidepassword(dest))

        revs, checkout = hg.addbranchrevs(repo, repo, revs, None)

        other = hg.peer(repo, opts, dest)

        if revs:

            revs = [repo.lookup(rev) for rev in revs]

        parent = discovery.findcommonoutgoing(

            repo, other, [], force=opts.get('force')).missing[0:1]

    else:

        if opts.get('force'):

            raise util.Abort(_('--force only allowed with --outgoing'))

    if opts.get('continue', False):

        if len(parent) != 0:

            raise util.Abort(_('no arguments allowed with --continue'))

        (parentctxnode, created, replaced,

         tmpnodes, existing, rules, keep, tip, replacemap) = readstate(repo)

        currentparent, wantnull = repo.dirstate.parents()

        parentctx = repo[parentctxnode]

        # existing is the list of revisions initially considered by

        # histedit. Here we use it to list new changesets, descendants

        # of parentctx without an 'existing' changeset in-between. We

        # also have to exclude 'existing' changesets which were

        # previously dropped.

        descendants = set(c.node() for c in

                repo.set('(%n::) - %n', parentctxnode, parentctxnode))

        existing = set(existing)

        notdropped = set(n for n in existing if n in descendants and

                (n not in replacemap or replacemap[n] in descendants))