def _context_url(GET, fileid=None):

    """

    Generates url for context lines

    :param fileid:

    """

    fileid = str(fileid) if fileid else None

    ig_ws = get_ignore_ws(fileid, GET)

    ln_ctx = (get_line_ctx(fileid, GET) or 3) * 2

    params = defaultdict(list)

    _update_with_GET(params, GET)

    # global option

    if fileid is None:

        if ln_ctx > 0:

            params['context'] += [ln_ctx]

        if ig_ws:

            ig_ws_key = 'ignorews'

            ig_ws_val = 1

    # per file option

    else:

        params[fileid] += ['C:%s' % ln_ctx]

        ig_ws_key = fileid

        ig_ws_val = 'WS:%s' % 1

    if ig_ws:

        params[ig_ws_key] += [ig_ws_val]

    lbl = _('%s line context') % ln_ctx

    params['anchor'] = fileid

    img = h.image(h.url('/images/icons/table_add.png'), lbl, class_='icon')

    return h.link_to(img, h.url.current(**params), title=lbl, class_='tooltip')

class ChangesetController(BaseRepoController):

    def __before__(self):

        super(ChangesetController, self).__before__()

        c.affected_files_cut_off = 60

        repo_model = RepoModel()

        c.users_array = repo_model.get_users_js()

        c.users_groups_array = repo_model.get_users_groups_js()

        c.anchor_url = anchor_url

        c.ignorews_url = _ignorews_url

        c.context_url = _context_url

        c.fulldiff = fulldiff = request.GET.get('fulldiff')

        #get ranges of revisions if preset

        rev_range = revision.split('...')[:2]

        enable_comments = True

        try:

            if len(rev_range) == 2:

                enable_comments = False

                rev_start = rev_range[0]

                rev_end = rev_range[1]

                rev_ranges = c.rhodecode_repo.get_changesets(start=rev_start,

                                                             end=rev_end)

            else:

                rev_ranges = [c.rhodecode_repo.get_changeset(revision)]

            c.cs_ranges = list(rev_ranges)

            if not c.cs_ranges:

                raise RepositoryError('Changeset range returned empty result')

        except (RepositoryError, ChangesetDoesNotExistError, Exception), e:

            log.error(traceback.format_exc())

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

            raise HTTPNotFound()

        c.changes = OrderedDict()

        c.lines_added = 0  # count of lines added

        c.lines_deleted = 0  # count of lines removes

        c.changeset_statuses = ChangesetStatus.STATUSES

        c.comments = []

        c.statuses = []

        c.inline_comments = []

        c.inline_cnt = 0

        # Iterate over ranges (default changeset view is always one changeset)

        for changeset in c.cs_ranges:

            inlines = []

            if method == 'show':

                c.statuses.extend([ChangesetStatusModel().get_status(

                            c.rhodecode_db_repo.repo_id, changeset.raw_id)])

                c.comments.extend(ChangesetCommentsModel()\

                                  .get_comments(c.rhodecode_db_repo.repo_id,

                                                revision=changeset.raw_id))

                    st = f['stats']

                    if st[0] != 'b':

                        c.lines_added += st[0]

                        c.lines_deleted += st[1]

                    fid = h.FID(changeset.raw_id, f['filename'])

                    diff = diff_processor.as_html(enable_comments=enable_comments,

                                                  parsed_lines=[f])

                    cs_changes[fid] = [cs1, cs2, f['operation'], f['filename'],

                                       diff, st]

            else:

                # downloads/raw we only need RAW diff nothing else

                diff = diff_processor.as_raw()

                cs_changes[''] = [None, None, None, None, diff, None]

            c.changes[changeset.raw_id] = cs_changes

        #sort comments by how they were generated

        c.comments = sorted(c.comments, key=lambda x: x.comment_id)

        # count inline comments

        for __, lines in c.inline_comments:

            for comments in lines.values():

                c.inline_cnt += len(comments)

        if len(c.cs_ranges) == 1:

            c.changeset = c.cs_ranges[0]

            c.parent_tmpl = ''.join(['# Parent  %s\n' % x.raw_id

                                     for x in c.changeset.parents])

        if method == 'download':

            response.content_type = 'text/plain'

            response.content_disposition = 'attachment; filename=%s.diff' \

                                            % revision[:12]

            return diff

        elif method == 'patch':

            response.content_type = 'text/plain'

            c.diff = safe_unicode(diff)

            return render('changeset/patch_changeset.html')

        elif method == 'raw':

            response.content_type = 'text/plain'

            return diff

        elif method == 'show':

            if len(c.cs_ranges) == 1:

                return render('changeset/changeset.html')

            else:

                return render('changeset/changeset_range.html')

    @LoginRequired()

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

                                   'repository.admin')

    def changeset_raw(self, revision):

    @LoginRequired()

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

                                   'repository.admin')

    def changeset_patch(self, revision):

    @LoginRequired()

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

                                   'repository.admin')

    def changeset_download(self, revision):

    @LoginRequired()

    @NotAnonymous()

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

                                   'repository.admin')

    @jsonify

    def comment(self, repo_name, revision):

        status = request.POST.get('changeset_status')

        change_status = request.POST.get('change_changeset_status')

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

        if status and change_status:

            text = text or (_('Status change -> %s')

                            % ChangesetStatus.get_status_lbl(status))

        c.co = comm = ChangesetCommentsModel().create(

            text=text,

            repo=c.rhodecode_db_repo.repo_id,

            user=c.rhodecode_user.user_id,

            revision=revision,

            f_path=request.POST.get('f_path'),

            line_no=request.POST.get('line'),

            status_change=(ChangesetStatus.get_status_lbl(status)

                           if status and change_status else None)

        )

        # get status if set !

        if status and change_status:

            # if latest status was from pull request and it's closed

            # disallow changing status !

            # dont_allow_on_closed_pull_request = True !

            try:

                ChangesetStatusModel().set_status(

                    c.rhodecode_db_repo.repo_id,

                    status,

                    c.rhodecode_user.user_id,

                    comm,

                    revision=revision,

                    dont_allow_on_closed_pull_request=True

                )

            except StatusChangeOnClosedPullRequestError:

                log.error(traceback.format_exc())

                msg = _('Changing status on a changeset associated with '

                        'a closed pull request is not allowed')

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

                return redirect(h.url('changeset_home', repo_name=repo_name,

                                      revision=revision))

        action_logger(self.rhodecode_user,