# states.py - introduce the state concept for mercurial changeset
#
# Copyright 2011 Peter Arrenbrecht <peter.arrenbrecht@gmail.com>
#                Logilab SA        <contact@logilab.fr>
#                Pierre-Yves David <pierre-yves.david@ens-lyon.org>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''a set of commands to handle changeset mutation'''

from mercurial import cmdutil
from mercurial import scmutil
from mercurial import node
from mercurial import error
from mercurial import extensions
from mercurial import commands
from mercurial import bookmarks
from mercurial import phases
from mercurial import commands
from mercurial import context
from mercurial import copies
from mercurial import util
from mercurial.i18n import _
from mercurial.commands import walkopts, commitopts, commitopts2, logopts
from mercurial import hg

### util function
#############################
def noderange(repo, revsets):
    """The same as revrange but return node"""
    return map(repo.changelog.node,
               scmutil.revrange(repo, revsets))



def warnunstable(orig, ui, repo, *args, **kwargs):
    """display warning is the command resulted in more instable changeset"""
    priorunstables = len(repo.revs('unstable()'))
    #print orig, priorunstables
    #print len(repo.revs('secret() - obsolete()'))
    try:
        return orig(ui, repo, *args, **kwargs)
    finally:
        newunstables = len(repo.revs('unstable()')) - priorunstables
        #print orig, newunstables
        #print len(repo.revs('secret() - obsolete()'))
        if newunstables > 0:
            ui.warn(_('%i new unstables changesets\n') % newunstables)


### extension check
#############################


### changeset rewriting logic
#############################

def rewrite(repo, old, updates, head, newbases, commitopts):
    """Return (nodeid, created) where nodeid is the identifier of the
    changeset generated by the rewrite process, and created is True if
    nodeid was actually created. If created is False, nodeid
    references a changeset existing before the rewrite call.
    """
    if len(old.parents()) > 1: #XXX remove this unecessary limitation.
        raise error.Abort(_('cannot amend merge changesets'))
    base = old.p1()
    bm = bookmarks.readcurrent(repo)

    wlock = repo.wlock()
    try:

        # commit a new version of the old changeset, including the update
        # collect all files which might be affected
        files = set(old.files())
        for u in updates:
            files.update(u.files())

        # Recompute copies (avoid recording a -> b -> a)
        copied = copies.pathcopies(base, head)


        # prune files which were reverted by the updates
        def samefile(f):
            if f in head.manifest():
                a = head.filectx(f)
                if f in base.manifest():
                    b = base.filectx(f)
                    return (a.data() == b.data()
                            and a.flags() == b.flags())
                else:
                    return False
            else:
                return f not in base.manifest()
        files = [f for f in files if not samefile(f)]
        # commit version of these files as defined by head
        headmf = head.manifest()
        def filectxfn(repo, ctx, path):
            if path in headmf:
                fctx = head[path]
                flags = fctx.flags()
                mctx = context.memfilectx(fctx.path(), fctx.data(),
                                          islink='l' in flags,
                                          isexec='x' in flags,
                                          copied=copied.get(path))
                return mctx
            raise IOError()
        if commitopts.get('message') and commitopts.get('logfile'):
            raise util.Abort(_('options --message and --logfile are mutually'
                               ' exclusive'))
        if commitopts.get('logfile'):
            message= open(commitopts['logfile']).read()
        elif commitopts.get('message'):
            message = commitopts['message']
        else:
            message = old.description()

        user = commitopts.get('user') or old.user()
        date = commitopts.get('date') or None # old.date()
        extra = dict(commitopts.get('extra', {}))
        extra['branch'] = head.branch()

        new = context.memctx(repo,
                             parents=newbases,
                             text=message,
                             files=files,
                             filectxfn=filectxfn,
                             user=user,
                             date=date,
                             extra=extra)

        if commitopts.get('edit'):
            new._text = cmdutil.commitforceeditor(repo, new, [])
        revcount = len(repo)
        newid = repo.commitctx(new)
        new = repo[newid]
        created = len(repo) != revcount
        if created:
            # update the bookmark
            if bm:
                repo._bookmarks[bm] = newid
                bookmarks.write(repo)

            # add evolution metadata
            collapsed = set([u.node() for u in updates] + [old.node()])
            repo.addcollapsedobsolete(collapsed, new.node())
            oldbookmarks = repo.nodebookmarks(old.node())
            for book in oldbookmarks:
                repo._bookmarks[book] = new.node()
            if oldbookmarks:
                bookmarks.write(repo)
        else:
            # newid is an existing revision. It could make sense to
            # replace revisions with existing ones but probably not by
            # default.
            pass
    finally:
        wlock.release()

    return newid, created

def relocate(repo, orig, dest):
    """rewrite <rev> on dest"""
    try:
        rebase = extensions.find('rebase')
        # dummy state to trick rebase node
        assert orig.p2().rev() == node.nullrev, 'no support yet'
        destbookmarks = repo.nodebookmarks(dest.node())
        cmdutil.duplicatecopies(repo, orig.node(), dest.node())
        nodesrc = orig.node()
        destphase = repo[nodesrc].phase()
        if rebase.rebasenode.func_code.co_argcount == 5:
            # rebasenode collapse argument was introduced by
            # d1afbf03e69a (2.3)
            rebase.rebasenode(repo, orig.node(), dest.node(),
                              {node.nullrev: node.nullrev}, False)
        else:
            rebase.rebasenode(repo, orig.node(), dest.node(),
                              {node.nullrev: node.nullrev})
        nodenew = rebase.concludenode(repo, orig.node(), dest.node(), node.nullid)
        oldbookmarks = repo.nodebookmarks(nodesrc)
        if nodenew is not None:
            phases.retractboundary(repo, destphase, [nodenew])
            repo.addobsolete(nodenew, nodesrc)
            for book in oldbookmarks:
                repo._bookmarks[book] = nodenew
        else:
            repo.addobsolete(node.nullid, nodesrc)
            # Behave like rebase, move bookmarks to dest
            for book in oldbookmarks:
                repo._bookmarks[book] = dest.node()
        for book in destbookmarks: # restore bookmark that rebase move
            repo._bookmarks[book] = dest.node()
        if oldbookmarks or destbookmarks:
            bookmarks.write(repo)
    except util.Abort:
        # Invalidate the previous setparents
        repo.dirstate.invalidate()
        raise


def stabilizableunstable(repo, pctx):
    """Return a changectx for an unstable changeset which can be
    stabilized on top of pctx or one of its descendants. None if none
    can be found.
    """
    def selfanddescendants(repo, pctx):
        yield pctx
        for ctx in pctx.descendants():
            yield ctx

    # Look for an unstable which can be stabilized as a child of
    # node. The unstable must be a child of one of node predecessors.
    for ctx in selfanddescendants(repo, pctx):
        unstables = list(repo.set('unstable() and children(obsancestors(%d))',
                                  ctx.rev()))
        if unstables:
            return unstables[0]
    return None

### new command
#############################
cmdtable = {}
command = cmdutil.command(cmdtable)

@command('^stabilize|evolve',
    [
     ('n', 'dry-run', False, 'Do nothing but printing what should be done'),
     ('A', 'any', False, 'Stabilize unstable change on any topological branch'),
    ],
    '')
def stabilize(ui, repo, **opts):
    """rebase an unstable changeset to make it stable again

    By default, take the first unstable changeset which could be
    rebased as child of the working directory parent revision or one
    of its descendants and rebase it.

    With --any, stabilize any unstable changeset.

    The working directory is updated to the rebased revision.
    """

    obsolete = extensions.find('obsolete')

    node = None
    if not opts['any']:
        node = stabilizableunstable(repo, repo['.'])
    if node is None:
        unstables = list(repo.set('unstable()'))
        if unstables and not opts['any']:
            ui.write_err(_('nothing to stabilize here\n'))
            ui.status(_('(%i unstable changesets, do you want --any ?)\n')
                      % len(unstables))
            return 2
        elif not unstables:
            ui.write_err(_('no unstable changeset\n'))
            return 1
        node = unstables[0]

    obs = node.parents()[0]
    if not obs.obsolete():
        obs = node.parents()[1]
    assert obs.obsolete()
    newer = obsolete.newerversion(repo, obs.node())
    if len(newer) > 1:
        ui.write_err(_("conflict rewriting. can't choose destination\n"))
        return 2
    targets = newer[0]
    if not targets:
        ui.write_err(_("does not handle kill parent yet\n"))
        return 2
    if len(targets) > 1:
        ui.write_err(_("does not handle splitted parent yet\n"))
        return 2
    target = targets[0]
    displayer = cmdutil.show_changeset(ui, repo, {'template': shorttemplate})
    target = repo[target]
    repo.ui.status(_('move:'))
    if not ui.quiet:
        displayer.show(node)
    repo.ui.status(_('atop:'))
    if not ui.quiet:
        displayer.show(target)
    todo= 'hg rebase -Dr %s -d %s\n' % (node, target)
    if opts['dry_run']:
        repo.ui.write(todo)
    else:
        repo.ui.note(todo)
        lock = repo.lock()
        try:
            relocate(repo, node, target)
        finally:
            lock.release()

shorttemplate = '[{rev}] {desc|firstline}\n'

@command('^gdown',
    [],
    'update to working directory parent and display summary lines')
def cmdgdown(ui, repo):
    """update to working directory parent an display summary lines"""
    wkctx = repo[None]
    wparents = wkctx.parents()
    if len(wparents) != 1:
        raise util.Abort('merge in progress')

    parents = wparents[0].parents()
    displayer = cmdutil.show_changeset(ui, repo, {'template': shorttemplate})
    if len(parents) == 1:
        p = parents[0]
        hg.update(repo, p.rev())
        displayer.show(p)
        return 0
    else:
        for p in parents:
            displayer.show(p)
        ui.warn(_('multiple parents, explicitly update to one\n'))
        return 1

@command('^gup',
    [],
    'update to working directory children and display summary lines')
def cmdup(ui, repo):
    """update to working directory children an display summary lines"""
    wkctx = repo[None]
    wparents = wkctx.parents()
    if len(wparents) != 1:
        raise util.Abort('merge in progress')

    children = [ctx for ctx in wparents[0].children() if not ctx.obsolete()]
    displayer = cmdutil.show_changeset(ui, repo, {'template': shorttemplate})
    if not children:
        ui.warn(_('No non-obsolete children\n'))
        return 1
    if len(children) == 1:
        c = children[0]
        hg.update(repo, c.rev())
        displayer.show(c)
        return 0
    else:
        for c in children:
            displayer.show(c)
        ui.warn(_('Multiple non-obsolete children, explicitly update to one\n'))
        return 1


@command('^kill|obsolete',
    [
    ('n', 'new', [], _("New changeset that justify this one to be killed"))
    ],
    '<revs>')
def kill(ui, repo, *revs, **opts):
    """mark a changeset as obsolete

    This update the parent directory to a not-killed parent if the current
    working directory parent are killed.

    XXX bookmark support
    XXX handle merge
    XXX check immutable first
    """
    wlock = repo.wlock()
    try:
        new = set(noderange(repo, opts['new']))
        targetnodes = set(noderange(repo, revs))
        if not new:
            new = [node.nullid]
        for n in targetnodes:
            if not repo[n].mutable():
                ui.warn(_("Can't kill immutable changeset %s") % repo[n])
            else:
                for ne in new:
                    repo.addobsolete(ne, n)
        # update to an unkilled parent
        wdp = repo['.']
        newnode = wdp
        while newnode.obsolete():
            newnode = newnode.parents()[0]
        if newnode.node() != wdp.node():
            commands.update(ui, repo, newnode.rev())
            ui.status(_('working directory now at %s\n') % newnode)

    finally:
        wlock.release()

@command('^amend|refresh',
    [('A', 'addremove', None,
     _('mark new/missing files as added/removed before committing')),
    ('n', 'note', '',
     _('use text as commit message for this update')),
    ('c', 'change', '',
     _('specifies the changeset to amend'), _('REV')),
    ('e', 'edit', False,
     _('edit commit message.'), _('')),
    ] + walkopts + commitopts + commitopts2,
    _('[OPTION]... [FILE]...'))

def amend(ui, repo, *pats, **opts):
    """combine a changeset with updates and replace it with a new one

    Commits a new changeset incorporating both the changes to the given files
    and all the changes from the current parent changeset into the repository.

    See :hg:`commit` for details about committing changes.

    If you don't specify -m, the parent's message will be reused.

    If you specify --change, amend additionally considers all changesets between
    the indicated changeset and the working copy parent as updates to be subsumed.

    Behind the scenes, Mercurial first commits the update as a regular child
    of the current parent. Then it creates a new commit on the parent's parents
    with the updated contents. Then it changes the working copy parent to this
    new combined changeset. Finally, the old changeset and its update are hidden
    from :hg:`log` (unless you use --hidden with log).

    Returns 0 on success, 1 if nothing changed.
    """

    # determine updates to subsume
    old = scmutil.revsingle(repo, opts.get('change') or '.')

    lock = repo.lock()
    try:
        wlock = repo.wlock()
        try:
            if old.phase() == phases.public:
                raise util.Abort(_("can not rewrite immutable changeset %s") % old)
            oldphase = old.phase()
            # commit current changes as update
            # code copied from commands.commit to avoid noisy messages
            ciopts = dict(opts)
            ciopts.pop('message', None)
            ciopts.pop('logfile', None)
            ciopts['message'] = opts.get('note') or ('amends %s' % old.hex())
            e = cmdutil.commiteditor
            def commitfunc(ui, repo, message, match, opts):
                return repo.commit(message, opts.get('user'), opts.get('date'), match,
                                   editor=e)
            revcount = len(repo)
            tempid = cmdutil.commit(ui, repo, commitfunc, pats, ciopts)
            if len(repo) == revcount:
                # No revision created
                tempid = None

            # find all changesets to be considered updates
            head = repo['.']
            updatenodes = set(repo.changelog.nodesbetween(
                    roots=[old.node()], heads=[head.node()])[0])
            updatenodes.remove(old.node())
            okoptions = ['message', 'logfile', 'edit', 'user']
            if not updatenodes:
                for o in okoptions:
                    if opts.get(o):
                        break
                else:
                    raise error.Abort(_('no updates found'))
            updates = [repo[n] for n in updatenodes]



            # perform amend
            if opts.get('edit'):
                opts['force_editor'] = True
            newid, created = rewrite(repo, old, updates, head,
                                     [old.p1().node(), old.p2().node()], opts)
            if created:
                # reroute the working copy parent to the new changeset
                phases.retractboundary(repo, oldphase, [newid])
                repo.dirstate.setparents(newid, node.nullid)
            else:
                # rewrite() recreated an existing revision, discard
                # the intermediate revision if any. No need to update
                # phases or parents.
                if tempid is not None:
                    repo.addobsolete(node.nullid, tempid)
                # XXX: need another message in collapse case.
                raise error.Abort(_('no updates found'))
        finally:
            wlock.release()
    finally:
        lock.release()




def commitwrapper(orig, ui, repo, *arg, **kwargs):
    lock = repo.lock()
    try:
        obsoleted = kwargs.get('obsolete', [])
        if obsoleted:
            obsoleted = repo.set('%lr', obsoleted)
        result = orig(ui, repo, *arg, **kwargs)
        if not result: # commit successed
            new = repo['-1']
            oldbookmarks = []
            for old in obsoleted:
                oldbookmarks.extend(repo.nodebookmarks(old.node()))
                repo.addobsolete(new.node(), old.node())
            for book in oldbookmarks:
                repo._bookmarks[book] = new.node()
            if oldbookmarks:
                bookmarks.write(repo)
        return result
    finally:
        lock.release()

def graftwrapper(orig, ui, repo, *revs, **kwargs):
    lock = repo.lock()
    try:
        if kwargs.get('old_obsolete'):
            obsoleted = kwargs.setdefault('obsolete', [])
            if kwargs['continue']:
                obsoleted.extend(repo.opener.read('graftstate').splitlines())
            else:
                obsoleted.extend(revs)
        # convert obsolete target into revs to avoid alias joke
        obsoleted = kwargs.setdefault('obsolete', [])
        obsoleted[:] = [str(i) for i in repo.revs('%lr', obsoleted)]
        if obsoleted and len(revs) > 1:

            raise error.Abort(_('Can not graft multiple revision while '
                                'obsoleting (for now).'))

        return commitwrapper(orig, ui, repo,*revs, **kwargs)
    finally:
        lock.release()

def extsetup(ui):
    try:
        obsolete = extensions.find('obsolete')
    except KeyError:
        raise error.Abort(_('evolution extension require obsolete extension.'))
    try:
        rebase = extensions.find('rebase')
    except KeyError:
        rebase = None
        raise error.Abort(_('evolution extension require rebase extension.'))

    entry = extensions.wrapcommand(commands.table, 'commit', commitwrapper)
    entry[1].append(('o', 'obsolete', [], _("this commit obsolet this revision")))
    entry = extensions.wrapcommand(commands.table, 'graft', graftwrapper)
    entry[1].append(('o', 'obsolete', [], _("this graft obsolet this revision")))
    entry[1].append(('O', 'old-obsolete', False, _("graft result obsolete graft source")))

    # warning about more obsolete
    for cmd in ['commit', 'push', 'pull', 'graft']:
        entry = extensions.wrapcommand(commands.table, cmd, warnunstable)
    for cmd in ['kill', 'amend']:
        entry = extensions.wrapcommand(cmdtable, cmd, warnunstable)

    if rebase is not None:
        entry = extensions.wrapcommand(rebase.cmdtable, 'rebase', warnunstable)