# -*- coding: utf-8 -*-

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# 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.changeset

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

changeset controller for pylons showing changes between

revisions

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 25, 2010

:author: marcink

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

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

"""

import logging

import traceback

from collections import defaultdict

from pylons import tmpl_context as c, request, response

from pylons.i18n.translation import _

from webob.exc import HTTPFound, HTTPForbidden, HTTPBadRequest, HTTPNotFound

from kallithea.lib.utils import jsonify

from kallithea.lib.vcs.exceptions import RepositoryError, \

    ChangesetDoesNotExistError

from kallithea.lib.compat import json

import kallithea.lib.helpers as h

from kallithea.lib.auth import LoginRequired, HasRepoPermissionAnyDecorator, \

    NotAnonymous

from kallithea.lib.base import BaseRepoController, render

from kallithea.lib.utils import action_logger

from kallithea.lib.compat import OrderedDict

from kallithea.lib import diffs

from kallithea.model.db import ChangesetComment, ChangesetStatus

from kallithea.model.comment import ChangesetCommentsModel

from kallithea.model.changeset_status import ChangesetStatusModel

from kallithea.model.meta import Session

from kallithea.model.repo import RepoModel

from kallithea.lib.diffs import LimitedDiffContainer

from kallithea.lib.exceptions import StatusChangeOnClosedPullRequestError

from kallithea.lib.vcs.backends.base import EmptyChangeset

from kallithea.lib.utils2 import safe_unicode

from kallithea.lib.graphmod import graph_data

log = logging.getLogger(__name__)

def _update_with_GET(params, GET):

    for k in ['diff1', 'diff2', 'diff']:

        params[k] += GET.getall(k)

def anchor_url(revision, path, GET):

    fid = h.FID(revision, path)

    return h.url.current(anchor=fid, **dict(GET))

def get_ignore_ws(fid, GET):

    ig_ws_global = GET.get('ignorews')

    ig_ws = filter(lambda k: k.startswith('WS'), GET.getall(fid))

    if ig_ws:

        try:

            return int(ig_ws[0].split(':')[-1])

        except ValueError:

            raise HTTPBadRequest()

    return ig_ws_global

def _ignorews_url(GET, fileid=None):

    fileid = str(fileid) if fileid else None

    params = defaultdict(list)

    _update_with_GET(params, GET)

    lbl = _('Show whitespace')

    ig_ws = get_ignore_ws(fileid, GET)

    ln_ctx = get_line_ctx(fileid, GET)

    # global option

    if fileid is None:

        if ig_ws is None:

            params['ignorews'] += [1]

            lbl = _('Ignore whitespace')

        ctx_key = 'context'

        ctx_val = ln_ctx

    # per file options

    else:

        if ig_ws is None:

            params[fileid] += ['WS:1']

            lbl = _('Ignore whitespace')

        ctx_key = fileid

        ctx_val = 'C:%s' % ln_ctx

    # if we have passed in ln_ctx pass it along to our params

    if ln_ctx:

        params[ctx_key] += [ctx_val]

    params['anchor'] = fileid

    icon = h.literal('<i class="icon-strike"></i>')

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

def get_line_ctx(fid, GET):

    ln_ctx_global = GET.get('context')

    if fid:

        ln_ctx = filter(lambda k: k.startswith('C'), GET.getall(fid))

    else:

        _ln_ctx = filter(lambda k: k.startswith('C'), GET)

        ln_ctx = GET.get(_ln_ctx[0]) if _ln_ctx  else ln_ctx_global

        if ln_ctx:

            ln_ctx = [ln_ctx]

    if ln_ctx:

        retval = ln_ctx[0].split(':')[-1]

    else:

        retval = ln_ctx_global

    try:

        return int(retval)

    except Exception:

        return 3

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 = _('Increase diff context to %(num)s lines') % {'num': ln_ctx}

    params['anchor'] = fileid

    icon = h.literal('<i class="icon-sort"></i>')

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

class ChangesetController(BaseRepoController):

    def __before__(self):

        super(ChangesetController, self).__before__()

        c.affected_files_cut_off = 60

    def __load_data(self):

        repo_model = RepoModel()

        c.users_array = repo_model.get_users_js()

        c.user_groups_array = repo_model.get_user_groups_js()

    def _index(self, revision, method):

        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

        c.cs_repo = c.db_repo

        try:

            if len(rev_range) == 2:

                enable_comments = False

                rev_start = rev_range[0]

                rev_end = rev_range[1]

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

                                                             end=rev_end)

            else:

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

            c.cs_ranges = list(rev_ranges)

            if not c.cs_ranges:

                raise RepositoryError('Changeset range returned empty result')

        except ChangesetDoesNotExistError:

            log.debug(traceback.format_exc())

            msg = _('Such revision does not exist for this repository')

            h.flash(msg, 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

        comments = dict()

        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:

            if method == 'show':

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

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

                # Changeset comments

                comments.update((com.comment_id, com)

                                for com in ChangesetCommentsModel()

                                .get_comments(c.db_repo.repo_id,

                                              revision=changeset.raw_id))

                # Status change comments - mostly from pull requests

                comments.update((st.changeset_comment_id, st.comment)

                                for st in ChangesetStatusModel()

                                .get_statuses(c.db_repo.repo_id,

                                              changeset.raw_id, with_revisions=True)

                                if st.changeset_comment_id is not None)

                inlines = ChangesetCommentsModel() \

                            .get_inline_comments(c.db_repo.repo_id,

                                                 revision=changeset.raw_id)

                c.inline_comments.extend(inlines)

            c.changes[changeset.raw_id] = []

            cs2 = changeset.raw_id

            cs1 = changeset.parents[0].raw_id if changeset.parents else EmptyChangeset().raw_id

            context_lcl = get_line_ctx('', request.GET)

            ign_whitespace_lcl = get_ignore_ws('', request.GET)

            _diff = c.db_repo_scm_instance.get_diff(cs1, cs2,

                ignore_whitespace=ign_whitespace_lcl, context=context_lcl)

            diff_limit = self.cut_off_limit if not fulldiff else None

            diff_processor = diffs.DiffProcessor(_diff,

                                                 vcs=c.db_repo_scm_instance.alias,

                                                 format='gitdiff',

                                                 diff_limit=diff_limit)

            cs_changes = OrderedDict()

            if method == 'show':

                _parsed = diff_processor.prepare()

                c.limited_diff = False

                if isinstance(_parsed, LimitedDiffContainer):

                    c.limited_diff = True

                for f in _parsed:

                    st = f['stats']

                    c.lines_added += st['added']

                    c.lines_deleted += st['deleted']

                    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 in creation order

        c.comments = [com for com_id, com in sorted(comments.items())]

        # 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':

            self.__load_data()

            if len(c.cs_ranges) == 1:

                return render('changeset/changeset.html')

            else:

                c.cs_ranges_org = None

                c.cs_comments = {}

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

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

                return render('changeset/changeset_range.html')

    @LoginRequired()

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

                                   'repository.admin')

    def index(self, revision, method='show'):

        return self._index(revision, method=method)

    @LoginRequired()

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

                                   'repository.admin')

    def changeset_raw(self, revision):

        return self._index(revision, method='raw')

    @LoginRequired()

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

                                   'repository.admin')

    def changeset_patch(self, revision):

        return self._index(revision, method='patch')

    @LoginRequired()

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

                                   'repository.admin')

    def changeset_download(self, revision):

        return self._index(revision, method='download')

    @LoginRequired()

    @NotAnonymous()

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

                                   'repository.admin')

    @jsonify

    def comment(self, repo_name, revision):

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

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

        c.comment = comment = ChangesetCommentsModel().create(

            text=text,

            repo=c.db_repo.repo_id,

            user=c.authuser.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 else None)

        )

        # get status if set !

        if 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.db_repo.repo_id,

                    status,

                    c.authuser.user_id,

                    comment,

                    revision=revision,

                    dont_allow_on_closed_pull_request=True

                )

            except StatusChangeOnClosedPullRequestError:

                log.debug(traceback.format_exc())

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

                        'a closed pull request is not allowed')

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

                raise HTTPFound(location=h.url('changeset_home', repo_name=repo_name,

                                      revision=revision))

        action_logger(self.authuser,

                      'user_commented_revision:%s' % revision,

                      c.db_repo, self.ip_addr, self.sa)

        Session().commit()

        if not request.environ.get('HTTP_X_PARTIAL_XHR'):

            raise HTTPFound(location=h.url('changeset_home', repo_name=repo_name,

                                  revision=revision))

        #only ajax below

        data = {

           'target_id': h.safeid(h.safe_unicode(request.POST.get('f_path'))),

        }

        if comment is not None:

            data.update(comment.get_dict())

            data.update({'rendered_text':

                         render('changeset/changeset_comment_block.html')})

        return data

    @LoginRequired()

    @NotAnonymous()

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

                                   'repository.admin')

    def preview_comment(self):

        if not request.environ.get('HTTP_X_PARTIAL_XHR'):

            raise HTTPBadRequest()

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

        if text:

        return ''

    @LoginRequired()

    @NotAnonymous()

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

                                   'repository.admin')

    @jsonify

    def delete_comment(self, repo_name, comment_id):

        co = ChangesetComment.get(comment_id)

        if not co:

            raise HTTPBadRequest()

        owner = co.author.user_id == c.authuser.user_id

        repo_admin = h.HasRepoPermissionAny('repository.admin')

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

            ChangesetCommentsModel().delete(comment=co)

            Session().commit()

            return True

        else:

            raise HTTPForbidden()

    @LoginRequired()

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

                                   'repository.admin')

    @jsonify

    def changeset_info(self, repo_name, revision):

        if request.is_xhr:

            try:

                return c.db_repo_scm_instance.get_changeset(revision)

            except ChangesetDoesNotExistError as e:

                return EmptyChangeset(message=str(e))

        else:

            raise HTTPBadRequest()

    @LoginRequired()

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

                                   'repository.admin')

    @jsonify

    def changeset_children(self, repo_name, revision):

        if request.is_xhr:

            changeset = c.db_repo_scm_instance.get_changeset(revision)

            result = {"results": []}

            if changeset.children:

                result = {"results": changeset.children}

            return result

        else:

            raise HTTPBadRequest()

    @LoginRequired()

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

                                   'repository.admin')

    @jsonify

    def changeset_parents(self, repo_name, revision):

        if request.is_xhr:

            changeset = c.db_repo_scm_instance.get_changeset(revision)

            result = {"results": []}

            if changeset.parents:

                result = {"results": changeset.parents}

            return result

        else:

            raise HTTPBadRequest()

            repo = None

            for rev in revs_ids[:revs_top_limit]:

                _op, _name = _get_op(rev)

                # we want parsed changesets, or new log store format is bad

                if parse_cs:

                    try:

                        if repo is None:

                            repo = user_log.repository.scm_instance

                        _rev = repo.get_changeset(rev)

                        revs.append(_rev)

                    except ChangesetDoesNotExistError:

                        log.error('cannot find revision %s in this repo', rev)

                        revs.append(rev)

                else:

                    _rev = AttributeDict({

                        'short_id': rev[:12],

                        'raw_id': rev,

                        'message': '',

                        'op': _op,

                        'ref_name': _name

                    })

                    revs.append(_rev)

        cs_links = [" " + ', '.join(

            [lnk(rev, repo_name) for rev in revs[:revs_limit]]

        )]

        _op1, _name1 = _get_op(revs_ids[0])

        _op2, _name2 = _get_op(revs_ids[-1])

        _rev = '%s...%s' % (_name1, _name2)

        compare_view = (

            ' <div class="compare_view tooltip" title="%s">'

            '<a href="%s">%s</a> </div>' % (

                _('Show all combined changesets %s->%s') % (

                    revs_ids[0][:12], revs_ids[-1][:12]

                ),

                url('changeset_home', repo_name=repo_name,

                    revision=_rev

                ),

                _('Compare view')

            )

        )

        # if we have exactly one more than normally displayed

        # just display it, takes less space than displaying

        # "and 1 more revisions"

        if len(revs_ids) == revs_limit + 1:

            cs_links.append(", " + lnk(revs[revs_limit], repo_name))

        # hidden-by-default ones

        if len(revs_ids) > revs_limit + 1:

            uniq_id = revs_ids[0]

            html_tmpl = (

                '<span> %s <a class="show_more" id="_%s" '

                'href="#more">%s</a> %s</span>'

            )

            if not feed:

                cs_links.append(html_tmpl % (

                      _('and'),

                      uniq_id, _('%s more') % (len(revs_ids) - revs_limit),

                      _('revisions')

                    )

                )

            if not feed:

                html_tmpl = '<span id="%s" style="display:none">, %s </span>'

            else:

                html_tmpl = '<span id="%s"> %s </span>'

            morelinks = ', '.join(

              [lnk(rev, repo_name) for rev in revs[revs_limit:]]

            )

            if len(revs_ids) > revs_top_limit:

                morelinks += ', ...'

            cs_links.append(html_tmpl % (uniq_id, morelinks))

        if len(revs) > 1:

            cs_links.append(compare_view)

        return ''.join(cs_links)

    def get_fork_name():

        repo_name = action_params

        url_ = url('summary_home', repo_name=repo_name)

        return _('Fork name %s') % link_to(action_params, url_)

    def get_user_name():

        user_name = action_params

        return user_name

    def get_users_group():

        group_name = action_params

        return group_name

    def get_pull_request():

        pull_request_id = action_params

        nice_id = PullRequest.make_nice_id(pull_request_id)

        deleted = user_log.repository is None

        if deleted:

            repo_name = user_log.repository_name

        else:

            repo_name = user_log.repository.repo_name

        return link_to(_('Pull request %s') % nice_id,

                    url('pullrequest_show', repo_name=repo_name,

                    pull_request_id=pull_request_id))

    def get_archive_name():

        archive_name = action_params

        return archive_name

    # action : translated str, callback(extractor), icon

    action_map = {

    'user_deleted_repo':           (_('[deleted] repository'),

                                    None, 'icon-trashcan'),

    'user_created_repo':           (_('[created] repository'),

                                    None, 'icon-plus'),

    'user_created_fork':           (_('[created] repository as fork'),

                                    None, 'icon-fork'),

    'user_forked_repo':            (_('[forked] repository'),

                                    get_fork_name, 'icon-fork'),

    'user_updated_repo':           (_('[updated] repository'),

                                    None, 'icon-pencil'),

    'user_downloaded_archive':      (_('[downloaded] archive from repository'),

                                    get_archive_name, 'icon-download-cloud'),

    'admin_deleted_repo':          (_('[delete] repository'),

                                    None, 'icon-trashcan'),

    'admin_created_repo':          (_('[created] repository'),

                                    None, 'icon-plus'),

    'admin_forked_repo':           (_('[forked] repository'),

                                    None, 'icon-fork'),

    'admin_updated_repo':          (_('[updated] repository'),

                                    None, 'icon-pencil'),

    'admin_created_user':          (_('[created] user'),

                                    get_user_name, 'icon-user'),

    'admin_updated_user':          (_('[updated] user'),

                                    get_user_name, 'icon-user'),

    'admin_created_users_group':   (_('[created] user group'),

                                    get_users_group, 'icon-pencil'),

    'admin_updated_users_group':   (_('[updated] user group'),

                                    get_users_group, 'icon-pencil'),

    'user_commented_revision':     (_('[commented] on revision in repository'),

                                    get_cs_links, 'icon-comment'),

    'user_commented_pull_request': (_('[commented] on pull request for'),

                                    get_pull_request, 'icon-comment'),

    'user_closed_pull_request':    (_('[closed] pull request for'),

                                    get_pull_request, 'icon-ok'),

    'push':                        (_('[pushed] into'),

                                    get_cs_links, 'icon-move-up'),

    'push_local':                  (_('[committed via Kallithea] into repository'),

                                    get_cs_links, 'icon-pencil'),

    'push_remote':                 (_('[pulled from remote] into repository'),

                                    get_cs_links, 'icon-move-up'),

    'pull':                        (_('[pulled] from'),

                                    None, 'icon-move-down'),

    'started_following_repo':      (_('[started following] repository'),

                                    None, 'icon-heart'),

    'stopped_following_repo':      (_('[stopped following] repository'),

                                    None, 'icon-heart-empty'),

    }

    action_str = action_map.get(action, action)

    if feed:

        action = action_str[0].replace('[', '').replace(']', '')

    else:

        action = action_str[0] \

            .replace('[', '<span class="journal_highlight">') \

            .replace(']', '</span>')

    action_params_func = lambda: ""

    if callable(action_str[1]):

        action_params_func = action_str[1]

    def action_parser_icon():

        action = user_log.action

        action_params = None

        x = action.split(':')

        if len(x) > 1:

            action, action_params = x

        tmpl = """<i class="%s" alt="%s"></i>"""

        ico = action_map.get(action, ['', '', ''])[2]

        return literal(tmpl % (ico, action))

    # returned callbacks we need to call to get

    return [lambda: literal(action), action_params_func, action_parser_icon]

#==============================================================================

# PERMS

#==============================================================================

from kallithea.lib.auth import HasPermissionAny, HasPermissionAll, \

HasRepoPermissionAny, HasRepoPermissionAll, HasRepoGroupPermissionAll, \

HasRepoGroupPermissionAny

#==============================================================================

# GRAVATAR URL

#==============================================================================

def gravatar(email_address, cls='', size=30, ssl_enabled=True):

    """return html element of the gravatar

    This method will return an <img> with the resolution double the size (for

    retina screens) of the image. If the url returned from gravatar_url is

    empty then we fallback to using an icon.

    """

    src = gravatar_url(email_address, size*2, ssl_enabled)

    #  here it makes sense to use style="width: ..." (instead of, say, a

    # stylesheet) because we using this to generate a high-res (retina) size

    tmpl = '<img alt="" class="{cls}" style="width: {size}px; height: {size}px" src="{src}"/>'

    # if src is empty then there was no gravatar, so we use a font icon

    if not src:

        tmpl = """<i class="icon-user {cls}" style="font-size: {size}px;"></i>"""

    tmpl = tmpl.format(cls=cls, size=size, src=src)

    return literal(tmpl)

def gravatar_url(email_address, size=30, ssl_enabled=True):

    # doh, we need to re-import those to mock it later

    from pylons import url

    from pylons import tmpl_context as c

    _def = 'anonymous@kallithea-scm.org'  # default gravatar

    _use_gravatar = c.visual.use_gravatar

    _gravatar_url = c.visual.gravatar_url or User.DEFAULT_GRAVATAR_URL

    email_address = email_address or _def

    if not _use_gravatar or not email_address or email_address == _def:

        return ""

    if _use_gravatar:

        _md5 = lambda s: hashlib.md5(s).hexdigest()

        tmpl = _gravatar_url

        parsed_url = urlparse.urlparse(url.current(qualified=True))

        tmpl = tmpl.replace('{email}', email_address) \

                   .replace('{md5email}', _md5(safe_str(email_address).lower())) \

                   .replace('{netloc}', parsed_url.netloc) \

                   .replace('{scheme}', parsed_url.scheme) \

                   .replace('{size}', safe_str(size))

        return tmpl

class Page(_Page):

    """

    Custom pager to match rendering style with YUI paginator

    """

    def _get_pos(self, cur_page, max_page, items):

        edge = (items / 2) + 1

        if (cur_page <= edge):

            radius = max(items / 2, items - cur_page)

        elif (max_page - cur_page) < edge:

            radius = (items - 1) - (max_page - cur_page)

        else:

            radius = items / 2

        left = max(1, (cur_page - (radius)))

        right = min(max_page, cur_page + (radius))

        return left, cur_page, right

    def _range(self, regexp_match):

        """

        Return range of linked pages (e.g. '1 2 [3] 4 5 6 7 8').

        Arguments:

        regexp_match

            A "re" (regular expressions) match object containing the

            radius of linked pages around the current page in

            regexp_match.group(1) as a string

        This function is supposed to be called as a callable in

        re.sub.

        """

        radius = int(regexp_match.group(1))

        # Compute the first and last page number within the radius

        # e.g. '1 .. 5 6 [7] 8 9 .. 12'

        # -> leftmost_page  = 5

        # -> rightmost_page = 9

        leftmost_page, _cur, rightmost_page = self._get_pos(self.page,

                                                            self.last_page,

                                                            (radius * 2) + 1)

        nav_items = []

        # Create a link to the first page (unless we are on the first page

        # or there would be no need to insert '..' spacers)

        if self.page != self.first_page and self.first_page < leftmost_page:

            nav_items.append(self._pagerlink(self.first_page, self.first_page))

        # Insert dots if there are pages between the first page

        # and the currently displayed page range

        if leftmost_page - self.first_page > 1:

            # Wrap in a SPAN tag if nolink_attr is set

            text_ = '..'

            if self.dotdot_attr:

                text_ = HTML.span(c=text_, **self.dotdot_attr)

            nav_items.append(text_)

        for thispage in xrange(leftmost_page, rightmost_page + 1):

            # Highlight the current page number and do not use a link

            text_ = str(thispage)

            if thispage == self.page:

                # Wrap in a SPAN tag if nolink_attr is set

                if self.curpage_attr:

                    text_ = HTML.span(c=text_, **self.curpage_attr)

                nav_items.append(text_)

            # Otherwise create just a link to that page

            else:

                nav_items.append(self._pagerlink(thispage, text_))

        # Insert dots if there are pages between the displayed

        # page numbers and the end of the page range

        if self.last_page - rightmost_page > 1:

            text_ = '..'

            # Wrap in a SPAN tag if nolink_attr is set

            if self.dotdot_attr:

                text_ = HTML.span(c=text_, **self.dotdot_attr)

            nav_items.append(text_)

        # Create a link to the very last page (unless we are on the last

        # page or there would be no need to insert '..' spacers)

        if self.page != self.last_page and rightmost_page < self.last_page:

            nav_items.append(self._pagerlink(self.last_page, self.last_page))

        #_page_link = url.current()

        #nav_items.append(literal('<link rel="prerender" href="%s?page=%s">' % (_page_link, str(int(self.page)+1))))

        #nav_items.append(literal('<link rel="prefetch" href="%s?page=%s">' % (_page_link, str(int(self.page)+1))))

        return self.separator.join(nav_items)

    def pager(self, format='~2~', page_param='page', partial_param='partial',

        show_if_single_page=False, separator=' ', onclick=None,

        symbol_first='<<', symbol_last='>>',

        symbol_previous='<', symbol_next='>',

        link_attr=None,

        curpage_attr=None,

        dotdot_attr=None, **kwargs):

        self.curpage_attr = curpage_attr or {'class': 'pager_curpage'}

        self.separator = separator

        self.pager_kwargs = kwargs

        self.page_param = page_param

        self.partial_param = partial_param

        self.onclick = onclick

        self.link_attr = link_attr or {'class': 'pager_link', 'rel': 'prerender'}

        self.dotdot_attr = dotdot_attr or {'class': 'pager_dotdot'}

        # Don't show navigator if there is no more than one page

        if self.page_count == 0 or (self.page_count == 1 and not show_if_single_page):

            return ''

        from string import Template

        # Replace ~...~ in token format by range of pages

        result = re.sub(r'~(\d+)~', self._range, format)

        # Interpolate '%' variables

        result = Template(result).safe_substitute({

            'first_page': self.first_page,

            'last_page': self.last_page,

            'page': self.page,

            'page_count': self.page_count,

            'items_per_page': self.items_per_page,

            'first_item': self.first_item,

            'last_item': self.last_item,

            'item_count': self.item_count,

            'link_first': self.page > self.first_page and \

                    self._pagerlink(self.first_page, symbol_first) or '',

            'link_last': self.page < self.last_page and \

                    self._pagerlink(self.last_page, symbol_last) or '',

            'link_previous': self.previous_page and \

                    self._pagerlink(self.previous_page, symbol_previous) \

                    or HTML.span(symbol_previous, class_="yui-pg-previous"),

            'link_next': self.next_page and \

                    self._pagerlink(self.next_page, symbol_next) \

                    or HTML.span(symbol_next, class_="yui-pg-next")

        })

        return literal(result)

#==============================================================================

# REPO PAGER, PAGER FOR REPOSITORY

#==============================================================================