# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""

kallithea.controllers.admin.admin

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Controller for Admin panel of Kallithea

This file was forked by the Kallithea project in July 2014.

Original author and date, and relevant copyright and licensing information is below:

:created_on: Apr 7, 2010

:author: marcink

:copyright: (c) 2013 RhodeCode GmbH, and others.

:license: GPLv3, see LICENSE.md for more details.

"""

import logging

from pylons import request, tmpl_context as c, url

from sqlalchemy.orm import joinedload

from whoosh.qparser.default import QueryParser

from whoosh.qparser.dateparse import DateParserPlugin

from whoosh import query

from sqlalchemy.sql.expression import or_, and_, func

from kallithea.model.db import UserLog

from kallithea.lib.auth import LoginRequired, HasPermissionAllDecorator

from kallithea.lib.base import BaseController, render

from kallithea.lib.utils2 import safe_int, remove_prefix, remove_suffix

from kallithea.lib.indexers import JOURNAL_SCHEMA

from kallithea.lib.helpers import Page

log = logging.getLogger(__name__)

def _journal_filter(user_log, search_term):

    """

    Filters sqlalchemy user_log based on search_term with whoosh Query language

    http://packages.python.org/Whoosh/querylang.html

    :param user_log:

    :param search_term:

    """

    qry = None

    if search_term:

        qp = QueryParser('repository', schema=JOURNAL_SCHEMA)

        qp.add_plugin(DateParserPlugin())

        qry = qp.parse(unicode(search_term))

    def wildcard_handler(col, wc_term):

        if wc_term.startswith('*') and not wc_term.endswith('*'):

            #postfix == endswith

            wc_term = remove_prefix(wc_term, prefix='*')

            return func.lower(col).endswith(wc_term)

        elif wc_term.startswith('*') and wc_term.endswith('*'):

            #wildcard == ilike

            wc_term = remove_prefix(wc_term, prefix='*')

            wc_term = remove_suffix(wc_term, suffix='*')

            return func.lower(col).contains(wc_term)

    def get_filterion(field, val, term):

        if field == 'repository':

            field = getattr(UserLog, 'repository_name')

        elif field == 'ip':

            field = getattr(UserLog, 'user_ip')

        elif field == 'date':

            field = getattr(UserLog, 'action_date')

        elif field == 'username':

            field = getattr(UserLog, 'username')

        else:

            field = getattr(UserLog, field)

        #sql filtering

        if isinstance(term, query.Wildcard):

            return wildcard_handler(field, val)

        elif isinstance(term, query.Prefix):

            return func.lower(field).startswith(func.lower(val))

        elif isinstance(term, query.DateRange):

            return and_(field >= val[0], field <= val[1])

        return func.lower(field) == func.lower(val)

    if isinstance(qry, (query.And, query.Term, query.Prefix, query.Wildcard,

                        query.DateRange)):

        if not isinstance(qry, query.And):

            qry = [qry]

        for term in qry:

            field = term.fieldname

            val = (term.text if not isinstance(term, query.DateRange)

                   else [term.startdate, term.enddate])

            user_log = user_log.filter(get_filterion(field, val, term))

    elif isinstance(qry, query.Or):

        filters = []

        for term in qry:

            field = term.fieldname

            val = (term.text if not isinstance(term, query.DateRange)

                   else [term.startdate, term.enddate])

            filters.append(get_filterion(field, val, term))

        user_log = user_log.filter(or_(*filters))

    return user_log

class AdminController(BaseController):

    @LoginRequired()

    def __before__(self):

        super(AdminController, self).__before__()

    @HasPermissionAllDecorator('hg.admin')

    def index(self):

        users_log = UserLog.query()\

                .options(joinedload(UserLog.user))\

                .options(joinedload(UserLog.repository))

        #FILTERING

        c.search_term = request.GET.get('filter')

        users_log = _journal_filter(users_log, c.search_term)

        users_log = users_log.order_by(UserLog.action_date.desc())

        if defaults:

            c.defaults.update(defaults)

        log.debug(formatted_json(defaults))

        return formencode.htmlfill.render(

            render('admin/auth/auth_settings.html'),

            defaults=c.defaults,

            errors=errors,

            prefix_error=False,

            encoding="UTF-8",

            force_defaults=False)

    def index(self):

        self.__load_defaults()

        return self.__render(defaults=None, errors=None)

    def auth_settings(self):

        """POST create and store auth settings"""

        self.__load_defaults()

        log.debug("POST Result: %s", formatted_json(dict(request.POST)))

        # First, parse only the plugin list (not the plugin settings).

        _auth_plugins_validator = AuthSettingsForm([]).fields['auth_plugins']

        try:

            new_enabled_plugins = _auth_plugins_validator.to_python(request.POST.get('auth_plugins'))

        except formencode.Invalid:

            # User provided an invalid plugin list. Just fall back to

            # the list of currently enabled plugins. (We'll re-validate

            # and show an error message to the user, below.)

            pass

        else:

            # Hide plugins that the user has asked to be disabled, but

            # do not show plugins that the user has asked to be enabled

            # (yet), since that'll cause validation errors and/or wrong

            # settings being applied (e.g. checkboxes being cleared),

            # since the plugin settings will not be in the POST data.

            c.enabled_plugins = [ p for p in c.enabled_plugins if p in new_enabled_plugins ]

        # Next, parse everything including plugin settings.

        _form = AuthSettingsForm(c.enabled_plugins)()

        try:

            form_result = _form.to_python(dict(request.POST))

            for k, v in form_result.items():

                if k == 'auth_plugins':

                    # we want to store it comma separated inside our settings

                    v = ','.join(v)

                setting = Setting.create_or_update(k, v)

                Session().add(setting)

            Session().commit()

            h.flash(_('Auth settings updated successfully'),

                       category='success')

        except formencode.Invalid as errors:

            log.error(traceback.format_exc())

            e = errors.error_dict or {}

            return self.__render(

                defaults=errors.value,

                errors=e,

            )

        except Exception:

            log.error(traceback.format_exc())

            h.flash(_('error occurred during update of auth settings'),

                    category='error')

        return redirect(url('auth_home'))

    @NotAnonymous()

    def new(self, format='html'):

        """GET /admin/gists/new: Form to create a new item"""

        # url('new_gist')

        self.__load_defaults()

        return render('admin/gists/new.html')

    @LoginRequired()

    @NotAnonymous()

    def update(self, gist_id):

        """PUT /admin/gists/gist_id: Update an existing item"""

        # Forms posted to this method should contain a hidden field:

        #    <input type="hidden" name="_method" value="PUT" />

        # Or using helpers:

        #    h.form(url('gist', gist_id=ID),

        #           method='put')

        # url('gist', gist_id=ID)

    @LoginRequired()

    @NotAnonymous()

    def delete(self, gist_id):

        """DELETE /admin/gists/gist_id: Delete an existing item"""

        # Forms posted to this method should contain a hidden field:

        #    <input type="hidden" name="_method" value="DELETE" />

        # Or using helpers:

        #    h.form(url('gist', gist_id=ID),

        #           method='delete')

        # url('gist', gist_id=ID)

        gist = GistModel().get_gist(gist_id)

        owner = gist.gist_owner == c.authuser.user_id

        if h.HasPermissionAny('hg.admin')() or owner:

            GistModel().delete(gist)

            Session().commit()

            h.flash(_('Deleted gist %s') % gist.gist_access_id, category='success')

        else:

            raise HTTPForbidden()

        return redirect(url('gists'))

    @LoginRequired()

    def show(self, gist_id, revision='tip', format='html', f_path=None):

        """GET /admin/gists/gist_id: Show a specific item"""

        # url('gist', gist_id=ID)

        c.gist = Gist.get_or_404(gist_id)

        #check if this gist is not expired

        if c.gist.gist_expires != -1:

            if time.time() > c.gist.gist_expires:

                raise HTTPNotFound()

        try:

            c.file_changeset, c.files = GistModel().get_gist_files(gist_id,

                                                            revision=revision)

        except VCSError:

            log.error(traceback.format_exc())

            raise HTTPNotFound()

        if format == 'raw':

            content = '\n\n'.join([f.content for f in c.files if (f_path is None or f.path == f_path)])

            response.content_type = 'text/plain'

            return content

        return render('admin/gists/show.html')

    @LoginRequired()

    @NotAnonymous()

    def edit(self, gist_id, format='html'):

        """GET /admin/gists/gist_id/edit: Form to edit an existing item"""

        # url('edit_gist', gist_id=ID)

        c.gist = Gist.get_or_404(gist_id)

        #check if this gist is not expired

        if c.gist.gist_expires != -1:

            if time.time() > c.gist.gist_expires:

                raise HTTPNotFound()

        try:

            c.file_changeset, c.files = GistModel().get_gist_files(gist_id)

        except VCSError:

            log.error(traceback.format_exc())

            raise HTTPNotFound()

        self.__load_defaults(extra_values=('0', _('Unmodified')))

        rendered = render('admin/gists/edit.html')

        if request.POST:

            rpost = request.POST

            nodes = {}

            for org_filename, filename, mimetype, content in zip(

                                                    rpost.getall('org_files'),

                                                    rpost.getall('files'),

                                                    rpost.getall('mimetypes'),

                                                    rpost.getall('contents')):

                nodes[org_filename] = {

                    'org_filename': org_filename,

                    'filename': filename,

                    'content': content,

                    'lexer': mimetype,

                }

            try:

                GistModel().update(

                    gist=c.gist,

                    description=rpost['description'],

                    owner=c.gist.owner,

                    gist_mapping=nodes,

                    gist_type=c.gist.gist_type,

                    lifetime=rpost['lifetime']

                )

                Session().commit()

                h.flash(_('Successfully updated gist content'), category='success')

            except NodeNotChangedError:

                # raised if nothing was changed in repo itself. We anyway then

                # store only DB stuff for gist

                Session().commit()

                h.flash(_('Successfully updated gist data'), category='success')

            except Exception:

                log.error(traceback.format_exc())

                h.flash(_('Error occurred during update of gist %s') % gist_id,

                        category='error')

            return redirect(url('gist', gist_id=gist_id))

        return rendered

    @LoginRequired()

    @NotAnonymous()

    @jsonify

    def check_revision(self, gist_id):

        c.gist = Gist.get_or_404(gist_id)

        last_rev = c.gist.scm_instance.get_changeset()

        success = True

        revision = request.POST.get('revision')

        ##TODO: maybe move this to model ?

        if revision != last_rev.raw_id:

            # our gist has newer version than we

            success = False

        return {'success': success}

        defaults.update(self._get_hg_ui_settings())

        return htmlfill.render(

            render('admin/settings/settings.html'),

            defaults=defaults,

            encoding="UTF-8",

            force_defaults=False)

    @HasPermissionAllDecorator('hg.admin')

    def settings_system(self):

        """GET /admin/settings/system: All items in the collection"""

        # url('admin_settings_system')

        c.active = 'system'

        defaults = Setting.get_app_settings()

        defaults.update(self._get_hg_ui_settings())

        import kallithea

        c.ini = kallithea.CONFIG

        c.update_url = defaults.get('update_url')

        server_info = Setting.get_server_info()

        for key, val in server_info.iteritems():

            setattr(c, key, val)

        return htmlfill.render(

            render('admin/settings/settings.html'),

            defaults=defaults,

            encoding="UTF-8",

            force_defaults=False)

    @HasPermissionAllDecorator('hg.admin')

    def settings_system_update(self):

        """GET /admin/settings/system/updates: All items in the collection"""

        # url('admin_settings_system_update')

        import json

        import urllib2

        from kallithea.lib.verlib import NormalizedVersion

        from kallithea import __version__

        defaults = Setting.get_app_settings()

        defaults.update(self._get_hg_ui_settings())

        _update_url = defaults.get('update_url', '')

        _update_url = "" # FIXME: disabled

        _err = lambda s: '<div style="color:#ff8888; padding:4px 0px">%s</div>' % (s)

        try:

            import kallithea

            ver = kallithea.__version__

            opener = urllib2.build_opener()

            opener.addheaders = [('User-agent', 'Kallithea-SCM/%s' % ver)]

            response = opener.open(_update_url)

            response_data = response.read()

            data = json.loads(response_data)

        except urllib2.URLError as e:

            log.error(traceback.format_exc())

            return _err('Failed to contact upgrade server: %r' % e)

        except ValueError as e:

            log.error(traceback.format_exc())

            return _err('Bad data sent from update server')

        latest = data['versions'][0]

        c.update_url = _update_url

        c.latest_data = latest

        c.latest_ver = latest['version']

        c.cur_ver = __version__

        c.should_upgrade = False

        if NormalizedVersion(c.latest_ver) > NormalizedVersion(c.cur_ver):

            c.should_upgrade = True

        c.important_notices = latest['general']

        return render('admin/settings/settings_system_update.html'),

    )

class JSONRPCController(WSGIController):

    """

     A WSGI-speaking JSON-RPC controller class

     See the specification:

     <http://json-rpc.org/wiki/specification>`.

     Valid controller return values should be json-serializable objects.

     Sub-classes should catch their exceptions and raise JSONRPCError

     if they want to pass meaningful errors to the client.

     """

    def _get_ip_addr(self, environ):

        return _get_ip(environ)

    def _get_method_args(self):

        """

        Return `self._rpc_args` to dispatched controller method

        chosen by __call__

        """

        return self._rpc_args

    def __call__(self, environ, start_response):

        """

        Parse the request body as JSON, look up the method on the

        controller and if it exists, dispatch to it.

        """

        try:

            return self._handle_request(environ, start_response)

        finally:

            meta.Session.remove()

    def _handle_request(self, environ, start_response):

        start = time.time()

        ip_addr = self.ip_addr = self._get_ip_addr(environ)

        self._req_id = None

        if 'CONTENT_LENGTH' not in environ:

            log.debug("No Content-Length")

            return jsonrpc_error(retid=self._req_id,

                                 message="No Content-Length in request")

        else:

            length = environ['CONTENT_LENGTH'] or 0

            length = int(environ['CONTENT_LENGTH'])

        if length == 0:

            log.debug("Content-Length is 0")

            return jsonrpc_error(retid=self._req_id,

                                 message="Content-Length is 0")

        raw_body = environ['wsgi.input'].read(length)

        try:

            json_body = json.loads(raw_body)

        except ValueError as e:

            # catch JSON errors Here

            return jsonrpc_error(retid=self._req_id,

                                 message="JSON parse error ERR:%s RAW:%r"

                                 % (e, raw_body))

        # check AUTH based on API key

        try:

            self._req_api_key = json_body['api_key']

            self._req_id = json_body['id']

            self._req_method = json_body['method']

            self._request_params = json_body['args']

            if not isinstance(self._request_params, dict):

                self._request_params = {}

            log.debug(

            )

        except KeyError as e:

            return jsonrpc_error(retid=self._req_id,

                                 message='Incorrect JSON query missing %s' % e)

        # check if we can find this session using api_key

        try:

            u = User.get_by_api_key(self._req_api_key)

            if u is None:

                return jsonrpc_error(retid=self._req_id,

                                     message='Invalid API key')

            auth_u = AuthUser(dbuser=u)

            if not AuthUser.check_ip_allowed(auth_u, ip_addr):

                return jsonrpc_error(retid=self._req_id,

                        message='request from IP:%s not allowed' % (ip_addr,))

            else:

        except Exception as e:

            return jsonrpc_error(retid=self._req_id,

                                 message='Invalid API key')

        self._error = None

        try:

            self._func = self._find_method()

        except AttributeError as e:

            return jsonrpc_error(retid=self._req_id,

                                 message=str(e))

        # now that we have a method, add self._req_params to

        # self.kargs and dispatch control to WGIController

        argspec = inspect.getargspec(self._func)

        arglist = argspec[0][1:]

        defaults = map(type, argspec[3] or [])

        default_empty = types.NotImplementedType

        # kw arguments required by this method

        func_kwargs = dict(izip_longest(reversed(arglist), reversed(defaults),

                                        fillvalue=default_empty))

        # this is little trick to inject logged in user for

        # perms decorators to work they expect the controller class to have

        # authuser attribute set

        self.authuser = auth_u

        # This attribute will need to be first param of a method that uses

        # api_key, which is translated to instance of user at that name

        USER_SESSION_ATTR = 'apiuser'

        if USER_SESSION_ATTR not in arglist:

            return jsonrpc_error(

                retid=self._req_id,

                message='This method [%s] does not support '

                         'authentication (missing %s param)' % (

                                    self._func.__name__, USER_SESSION_ATTR)

            )

        # get our arglist and check if we provided them as args

        for arg, default in func_kwargs.iteritems():

            if arg == USER_SESSION_ATTR:

                # USER_SESSION_ATTR is something translated from API key and

                # this is checked before so we don't need validate it

                continue

            # skip the required param check if it's default value is

            if default == default_empty and arg not in self._request_params:

                return jsonrpc_error(

                    retid=self._req_id,

                    message=(

                        'Missing non optional `%s` arg in JSON DATA' % arg

                    )

                )

        self._rpc_args = {USER_SESSION_ATTR: u}

        self._rpc_args.update(self._request_params)

        self._rpc_args['action'] = self._req_method

        self._rpc_args['environ'] = environ

        self._rpc_args['start_response'] = start_response

        status = []

        headers = []

        exc_info = []

        def change_content(new_status, new_headers, new_exc_info=None):

            status.append(new_status)

            headers.extend(new_headers)

            exc_info.append(new_exc_info)

        output = WSGIController.__call__(self, environ, change_content)

        output = list(output)

        headers.append(('Content-Length', str(len(output[0]))))

        replace_header(headers, 'Content-Type', 'application/json')

        start_response(status[0], headers, exc_info[0])

        log.info('IP: %s Request to %s time: %.3fs' % (

            self._get_ip_addr(environ),

            safe_unicode(_get_access_path(environ)), time.time() - start)

        )

        return output

    def _dispatch_call(self):

        """

        Implement dispatch interface specified by WSGIController

        """

        raw_response = ''

        try:

            raw_response = self._inspect_call(self._func)

            if isinstance(raw_response, HTTPError):

                self._error = str(raw_response)

        except JSONRPCError as e:

            self._error = safe_str(e)

        except Exception as e:

            json_exc = JSONRPCError('Internal server error')

            self._error = safe_str(json_exc)

        if self._error is not None:

            raw_response = None

        response = dict(id=self._req_id, result=raw_response, error=self._error)

        try:

            return json.dumps(response)

        except TypeError as e:

            return json.dumps(

                dict(

                    id=self._req_id,

                    result=None,

                    error="Error encoding response"

                )

            )

    def _find_method(self):

        """

        Return method named by `self._req_method` in controller if able

        """

        if self._req_method.startswith('_'):

            raise AttributeError("Method not allowed")

        try:

            func = getattr(self, self._req_method, None)

        except UnicodeEncodeError:

            raise AttributeError("Problem decoding unicode in requested "

                                 "method name.")

        if isinstance(func, types.MethodType):

            return func

        else:

            raise AttributeError("No such method: %s" % (self._req_method,))

            return c.db_repo_scm_instance.get_changeset(rev)

        except EmptyRepositoryError as e:

            h.flash(h.literal(_('There are no changesets yet')),

                    category='error')

        except RepositoryError as e:

            log.error(traceback.format_exc())

            h.flash(safe_str(e), category='error')

        raise HTTPBadRequest()

    @LoginRequired()

    @HasRepoPermissionAnyDecorator('repository.read', 'repository.write',

                                   'repository.admin')

    def index(self, repo_name, revision=None, f_path=None):

        # Fix URL after page size form submission via GET

        # TODO: Somehow just don't send this extra junk in the GET URL

        if request.GET.get('set'):

            request.GET.pop('set', None)

            request.GET.pop('_authentication_token', None)

            if revision is None:

                return redirect(url('changelog_home', repo_name=repo_name, **request.GET))

            return redirect(url('changelog_file_home', repo_name=repo_name, revision=revision, f_path=f_path, **request.GET))

        limit = 2000

        default = 100

        if request.GET.get('size'):

            c.size = max(min(safe_int(request.GET.get('size')), limit), 1)

            session['changelog_size'] = c.size

            session.save()

        else:

            c.size = int(session.get('changelog_size', default))

        # min size must be 1

        c.size = max(c.size, 1)

        p = safe_int(request.GET.get('page', 1), 1)

        branch_name = request.GET.get('branch', None)

        if (branch_name and

            branch_name not in c.db_repo_scm_instance.branches and

            branch_name not in c.db_repo_scm_instance.closed_branches and

            not revision):

            return redirect(url('changelog_file_home', repo_name=c.repo_name,

                                    revision=branch_name, f_path=f_path or ''))

        if revision == 'tip':

            revision = None

        c.changelog_for_path = f_path

        try:

            if f_path:

                # get the history for the file !

                tip_cs = c.db_repo_scm_instance.get_changeset()

                try:

                    collection = tip_cs.get_file_history(f_path)

                except (NodeDoesNotExistError, ChangesetError):

                    #this node is not present at tip !

                    try:

                        cs = self.__get_cs(revision, repo_name)

                        collection = cs.get_file_history(f_path)

                    except RepositoryError as e:

                        h.flash(safe_str(e), category='warning')

                        redirect(h.url('changelog_home', repo_name=repo_name))

                collection = list(reversed(collection))

            else:

                collection = c.db_repo_scm_instance.get_changesets(start=0, end=revision,

                                                        branch_name=branch_name)

            c.total_cs = len(collection)

            c.pagination = RepoPage(collection, page=p, item_count=c.total_cs,

                                    items_per_page=c.size, branch=branch_name,)

            page_revisions = [x.raw_id for x in c.pagination]

            c.comments = c.db_repo.get_comments(page_revisions)

            c.statuses = c.db_repo.statuses(page_revisions)

        except EmptyRepositoryError as e:

            h.flash(safe_str(e), category='warning')

            return redirect(url('summary_home', repo_name=c.repo_name))

        except (RepositoryError, ChangesetDoesNotExistError, Exception) as e:

            log.error(traceback.format_exc())

            h.flash(safe_str(e), category='error')

            return redirect(url('changelog_home', repo_name=c.repo_name))

        c.branch_name = branch_name

        c.branch_filters = [('', _('None'))] + \

            [(k, k) for k in c.db_repo_scm_instance.branches.keys()]

        if c.db_repo_scm_instance.closed_branches:

            prefix = _('(closed)') + ' '

            c.branch_filters += [('-', '-')] + \

                [(k, prefix + k) for k in c.db_repo_scm_instance.closed_branches.keys()]

        revs = []

        if not f_path:

            revs = [x.revision for x in c.pagination]

        c.jsdata = json.dumps(graph_data(c.db_repo_scm_instance, revs))

        c.revision = revision # requested revision ref

        c.first_revision = c.pagination[0] # pagination is never empty here!

        return render('changelog/changelog.html')

        other_repo = Repository.get_by_repo_name(other_repo)

        if org_repo is None:

            msg = 'Could not find org repo %s' % org_repo

            log.error(msg)

            h.flash(msg, category='error')

            return redirect(url('compare_home', repo_name=c.repo_name))

        if other_repo is None:

            msg = 'Could not find other repo %s' % other_repo

            log.error(msg)

            h.flash(msg, category='error')

            return redirect(url('compare_home', repo_name=c.repo_name))

        if org_repo.scm_instance.alias != other_repo.scm_instance.alias:

            msg = 'compare of two different kind of remote repos not available'

            log.error(msg)

            h.flash(msg, category='error')

            return redirect(url('compare_home', repo_name=c.repo_name))

        c.a_rev = self._get_ref_rev(org_repo, org_ref_type, org_ref_name,

            returnempty=True)

        c.cs_rev = self._get_ref_rev(other_repo, other_ref_type, other_ref_name)

        c.compare_home = False

        c.a_repo = org_repo

        c.a_ref_name = org_ref_name

        c.a_ref_type = org_ref_type

        c.cs_repo = other_repo

        c.cs_ref_name = other_ref_name

        c.cs_ref_type = other_ref_type

        c.cs_ranges, c.cs_ranges_org, c.ancestor = self._get_changesets(

            org_repo.scm_instance.alias, org_repo.scm_instance, c.a_rev,

            other_repo.scm_instance, c.cs_rev)

        raw_ids = [x.raw_id for x in c.cs_ranges]

        c.cs_comments = other_repo.get_comments(raw_ids)

        c.statuses = other_repo.statuses(raw_ids)

        revs = [ctx.revision for ctx in reversed(c.cs_ranges)]

        c.jsdata = json.dumps(graph_data(c.cs_repo.scm_instance, revs))

        if partial:

            return render('compare/compare_cs.html')

        if merge and c.ancestor:

            # case we want a simple diff without incoming changesets,

            # previewing what will be merged.

            # Make the diff on the other repo (which is known to have other_rev)

            rev1 = c.ancestor

            org_repo = other_repo

        else: # comparing tips, not necessarily linearly related

            if merge:

                log.error('Unable to find ancestor revision')

            if org_repo != other_repo:

                # TODO: we could do this by using hg unionrepo

                log.error('cannot compare across repos %s and %s', org_repo, other_repo)

                h.flash(_('Cannot compare repositories without using common ancestor'), category='error')

                raise HTTPBadRequest

            rev1 = c.a_rev

        diff_limit = self.cut_off_limit if not c.fulldiff else None