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

### 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()
    updatebookmarks = _bookmarksupdater(repo, old.node())

    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:
            updatebookmarks(newid)
            # add evolution metadata
            collapsed = set([u.node() for u in updates] + [old.node()])
            repo.addcollapsedobsolete(collapsed, new.node())
        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

def _bookmarksupdater(repo, oldid):
    """Return a callable update(newid) updating the current bookmark
    and bookmarks bound to oldid to newid.
    """
    bm = bookmarks.readcurrent(repo)
    def updatebookmarks(newid):
        dirty = False
        if bm:
            repo._bookmarks[bm] = newid
            dirty = True
        oldbookmarks = repo.nodebookmarks(oldid)
        if oldbookmarks:
            for b in oldbookmarks:
                repo._bookmarks[b] = newid
            dirty = True
        if dirty:
            bookmarks.write(repo)
    return updatebookmarks

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

@command('^stabilize|evolve',
    [('n', 'dry-run', False, 'do not perform actions, print what to be done'),
    ('A', 'any', False, 'stabilize any unstable changeset'),],
    _('[OPTIONS]...'))
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',
         [],
         '')
def cmdgdown(ui, repo):
    """update to 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',
         [],
         '')
def cmdup(ui, repo):
    """update to child 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|prune',
    [('n', 'new', [], _("successor changeset"))],
    _('[OPTION] REV...'))
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 changesets to amend'), _('REV')),
    ('e', 'edit', False, _('invoke editor on commit messages')),
    ] + 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 _commitfiltered(repo, ctx, match):
    """Recommit ctx with changed files not in match. Return the new
    node identifier, or None if nothing changed.
    """
    base = ctx.p1()
    m, a, r = repo.status(base, ctx)[:3]
    allfiles = set(m + a + r)
    files = set(f for f in allfiles if not match(f))
    if files == allfiles:
        return None

    # Filter copies
    copied = copies.pathcopies(base, ctx)
    copied = dict((src, dst) for src, dst in copied.iteritems()
                  if dst in files)
    def filectxfn(repo, memctx, path):
        if path not in ctx:
            raise IOError()
        fctx = ctx[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

    new = context.memctx(repo,
                         parents=[base.node(), node.nullid],
                         text=ctx.description(),
                         files=files,
                         filectxfn=filectxfn,
                         user=ctx.user(),
                         date=ctx.date(),
                         extra=ctx.extra())
    # commitctx always create a new revision, no need to check
    newid = repo.commitctx(new)
    return newid

def _uncommitdirstate(repo, oldctx, match):
    """Fix the dirstate after switching the working directory from
    oldctx to a copy of oldctx not containing changed files matched by
    match.
    """
    ctx = repo['.']
    ds = repo.dirstate
    copies = dict(ds.copies())
    m, a, r = repo.status(oldctx.p1(), oldctx, match=match)[:3]
    for f in m:
        if ds[f] == 'r':
            # modified + removed -> removed
            continue
        ds.normallookup(f)

    for f in a:
        if ds[f] == 'r':
            # added + removed -> unknown
            ds.drop(f)
        elif ds[f] != 'a':
            ds.add(f)

    for f in r:
        if ds[f] == 'a':
            # removed + added -> normal
            ds.normallookup(f)
        elif ds[f] != 'r':
            ds.remove(f)

    # Merge old parent and old working dir copies
    oldcopies = {}
    for f in (m + a):
        src = oldctx[f].renamed()
        if src:
            oldcopies[f] = src[0]
    oldcopies.update(copies)
    copies = dict((dst, oldcopies.get(src, src))
                  for dst, src in oldcopies.iteritems())
    # Adjust the dirstate copies
    for dst, src in copies.iteritems():
        if (src not in ctx or dst in ctx or ds[dst] != 'a'):
            src = None
        ds.copy(src, dst)

@command('^uncommit',
    [('a', 'all', None, _('uncommit all changes when no arguments given')),
     ] + commands.walkopts,
    _('[OPTION]... [NAME]'))
def uncommit(ui, repo, *pats, **opts):
    """move changes from parent revision to working directory

    Changes to selected files in parent revision appear again as
    uncommitted changed in the working directory. A new revision
    without selected changes is created, becomes the new parent and
    obsoletes the previous one.

    The --include option specify pattern to uncommit
    The --exclude option specify pattern to keep in the commit

    Return 0 if changed files are uncommitted.
    """
    lock = repo.lock()
    try:
        wlock = repo.wlock()
        try:
            wctx = repo[None]
            if len(wctx.parents()) <= 0:
                raise util.Abort(_("cannot uncommit null changeset"))
            if len(wctx.parents()) > 1:
                raise util.Abort(_("cannot uncommit while merging"))
            old = repo['.']
            if old.phase() == phases.public:
                raise util.Abort(_("cannot rewrite immutable changeset"))
            if len(old.parents()) > 1:
                raise util.Abort(_("cannot uncommit merge changeset"))
            oldphase = old.phase()
            updatebookmarks = _bookmarksupdater(repo, old.node())
            # Recommit the filtered changeset
            newid = None
            if (pats or opts.get('include') or opts.get('exclude')
                or opts.get('all')):
                match = scmutil.match(old, pats, opts)
                newid = _commitfiltered(repo, old, match)
            if newid is None:
                raise util.Abort(_('nothing to uncommit'))
            # Move local changes on filtered changeset
            repo.addobsolete(newid, old.node())
            phases.retractboundary(repo, oldphase, [newid])
            repo.dirstate.setparents(newid, node.nullid)
            _uncommitdirstate(repo, old, match)
            updatebookmarks(newid)
            if not repo[newid].files():
                ui.warn(_("new changeset is empty\n"))
                ui.status(_('(use "hg kill ." to remove it)\n'))
        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', [],
                     _("make commit obsolete this revision")))
    entry = extensions.wrapcommand(commands.table, 'graft', graftwrapper)
    entry[1].append(('o', 'obsolete', [],
                     _("make graft obsoletes this revision")))
    entry[1].append(('O', 'old-obsolete', False,
                     _("make graft obsoletes its source")))

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

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