# -*- 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.lib.utils

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

Utilities library for 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 18, 2010

:author: marcink

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

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

"""

import datetime

import logging

import os

import re

import sys

import traceback

import urllib.error

from distutils.version import StrictVersion

import mercurial.config

import mercurial.error

import mercurial.ui

import kallithea.config.conf

from kallithea.lib.exceptions import InvalidCloneUriException

from kallithea.lib.vcs.backends.git.repository import GitRepository

from kallithea.lib.vcs.backends.hg.repository import MercurialRepository

from kallithea.lib.vcs.conf import settings

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

from kallithea.lib.vcs.utils.fakemod import create_module

from kallithea.lib.vcs.utils.helpers import get_scm

from kallithea.model import meta

from kallithea.model.db import RepoGroup, Repository, Setting, Ui, User, UserGroup, UserLog

log = logging.getLogger(__name__)

REMOVED_REPO_PAT = re.compile(r'rm__\d{8}_\d{6}_\d{6}_.*')

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

# PERM DECORATOR HELPERS FOR EXTRACTING NAMES FOR PERM CHECKS

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

def get_repo_slug(request):

    _repo = request.environ['pylons.routes_dict'].get('repo_name')

    if _repo:

        _repo = _repo.rstrip('/')

    return _repo

def get_repo_group_slug(request):

    _group = request.environ['pylons.routes_dict'].get('group_name')

    if _group:

        _group = _group.rstrip('/')

    return _group

def get_user_group_slug(request):

    _group = request.environ['pylons.routes_dict'].get('id')

    _group = UserGroup.get(_group)

    if _group:

        return _group.users_group_name

    return None

def _get_permanent_id(s):

    """Helper for decoding stable URLs with repo ID. For a string like '_123'

    return 123.

    """

    by_id_match = re.match(r'^_(\d+)$', s)

    if by_id_match is None:

        return None

    return int(by_id_match.group(1))

def fix_repo_id_name(path):

    """

    Rewrite repo_name for _<ID> permanent URLs.

    Given a path, if the first path element is like _<ID>, return the path with

    this part expanded to the corresponding full repo name, else return the

    provided path.

    """

    first, rest = path, ''

    if '/' in path:

        first, rest_ = path.split('/', 1)

        rest = '/' + rest_

    repo_id = _get_permanent_id(first)

    if repo_id is not None:

        repo = Repository.get(repo_id)

        if repo is not None:

            return repo.repo_name + rest

    return path

def action_logger(user, action, repo, ipaddr='', commit=False):

    """

    Action logger for various actions made by users

    :param user: user that made this action, can be a unique username string or

        object containing user_id attribute

    :param action: action to log, should be on of predefined unique actions for

        easy translations

    :param repo: string name of repository or object containing repo_id,

        that action was made on

    :param ipaddr: optional IP address from what the action was made

    """

    # if we don't get explicit IP address try to get one from registered user

    # in tmpl context var

    if not ipaddr:

        ipaddr = getattr(get_current_authuser(), 'ip_addr', '')

    if getattr(user, 'user_id', None):

        user_obj = User.get(user.user_id)

    elif isinstance(user, str):

        user_obj = User.get_by_username(user)

    else:

        raise Exception('You have to provide a user object or a username')

    if getattr(repo, 'repo_id', None):

        repo_obj = Repository.get(repo.repo_id)

        repo_name = repo_obj.repo_name

    elif isinstance(repo, str):

        repo_name = repo.lstrip('/')

        repo_obj = Repository.get_by_repo_name(repo_name)

    else:

        repo_obj = None

        repo_name = ''

    user_log = UserLog()

    user_log.user_id = user_obj.user_id

    user_log.username = user_obj.username

    user_log.action = action

    user_log.repository = repo_obj

    user_log.repository_name = repo_name

    user_log.action_date = datetime.datetime.now()

    user_log.user_ip = ipaddr

    meta.Session().add(user_log)

    log.info('Logging action:%s on %s by user:%s ip:%s',

             action, repo, user_obj, ipaddr)

    if commit:

        meta.Session().commit()

def get_filesystem_repos(path):

    """

    Scans given path for repos and return (name,(type,path)) tuple

    :param path: path to scan for repositories

    :param recursive: recursive search and return names with subdirs in front

    """

    # remove ending slash for better results

    path = path.rstrip(os.sep)

    log.debug('now scanning in %s', path)

    def isdir(*n):

        return os.path.isdir(os.path.join(*n))

    for root, dirs, _files in os.walk(path):

        recurse_dirs = []

        for subdir in dirs:

            # skip removed repos

            if REMOVED_REPO_PAT.match(subdir):

                continue

            # skip .<something> dirs TODO: rly? then we should prevent creating them ...

            if subdir.startswith('.'):

                continue

            cur_path = os.path.join(root, subdir)

            if isdir(cur_path, '.git'):

                log.warning('ignoring non-bare Git repo: %s', cur_path)

                continue

            if (isdir(cur_path, '.hg') or

                isdir(cur_path, '.svn') or

                isdir(cur_path, 'objects') and (isdir(cur_path, 'refs') or

                                                os.path.isfile(os.path.join(cur_path, 'packed-refs')))):

                if not os.access(cur_path, os.R_OK) or not os.access(cur_path, os.X_OK):

                    log.warning('ignoring repo path without access: %s', cur_path)

                    continue

                if not os.access(cur_path, os.W_OK):

                    log.warning('repo path without write access: %s', cur_path)

                try:

                    scm_info = get_scm(cur_path)

                    assert cur_path.startswith(path)

                    repo_path = cur_path[len(path) + 1:]

                    yield repo_path, scm_info

                    continue # no recursion

                except VCSError:

                    # We should perhaps ignore such broken repos, but especially

                    # the bare git detection is unreliable so we dive into it

                    pass

            recurse_dirs.append(subdir)

        dirs[:] = recurse_dirs

def is_valid_repo_uri(repo_type, url, ui):

    """Check if the url seems like a valid remote repo location

    Raise InvalidCloneUriException if any problems"""

    if repo_type == 'hg':

        if url.startswith('http') or url.startswith('ssh'):

            # initially check if it's at least the proper URL

            # or does it pass basic auth

            try:

                MercurialRepository._check_url(url, ui)

    groups = path.split(kallithea.URL_SEP)

    parent = None

    group = None

    # last element is repo in nested groups structure

    groups = groups[:-1]

    rgm = RepoGroupModel()

    owner = User.get_first_admin()

    for lvl, group_name in enumerate(groups):

        group_name = '/'.join(groups[:lvl] + [group_name])

        group = RepoGroup.get_by_group_name(group_name)

        desc = '%s group' % group_name

        # skip folders that are now removed repos

        if REMOVED_REPO_PAT.match(group_name):

            break

        if group is None:

            log.debug('creating group level: %s group_name: %s',

                      lvl, group_name)

            group = RepoGroup(group_name, parent)

            group.group_description = desc

            group.owner = owner

            sa.add(group)

            rgm._create_default_perms(group)

            sa.flush()

        parent = group

    return group

def repo2db_mapper(initial_repo_dict, remove_obsolete=False,

                   install_git_hooks=False, user=None, overwrite_git_hooks=False):

    """

    maps all repos given in initial_repo_dict, non existing repositories

    are created, if remove_obsolete is True it also check for db entries

    that are not in initial_repo_dict and removes them.

    :param initial_repo_dict: mapping with repositories found by scanning methods

    :param remove_obsolete: check for obsolete entries in database

    :param install_git_hooks: if this is True, also check and install git hook

        for a repo if missing

    :param overwrite_git_hooks: if this is True, overwrite any existing git hooks

        that may be encountered (even if user-deployed)

    """

    from kallithea.model.repo import RepoModel

    from kallithea.model.scm import ScmModel

    sa = meta.Session()

    repo_model = RepoModel()

    if user is None:

        user = User.get_first_admin()

    added = []

    # creation defaults

    defs = Setting.get_default_repo_settings(strip_prefix=True)

    enable_statistics = defs.get('repo_enable_statistics')

    enable_downloads = defs.get('repo_enable_downloads')

    private = defs.get('repo_private')

    for name, repo in sorted(initial_repo_dict.items()):

        group = map_groups(name)

        db_repo = repo_model.get_by_repo_name(name)

        # found repo that is on filesystem not in Kallithea database

        if not db_repo:

            log.info('repository %s not found, creating now', name)

            added.append(name)

            desc = (repo.description

                    if repo.description != 'unknown'

                    else '%s repository' % name)

            new_repo = repo_model._create_repo(

                repo_name=name,

                repo_type=repo.alias,

                description=desc,

                repo_group=getattr(group, 'group_id', None),

                owner=user,

                enable_downloads=enable_downloads,

                enable_statistics=enable_statistics,

                private=private,

                state=Repository.STATE_CREATED

            )

            sa.commit()

            # we added that repo just now, and make sure it has githook

            # installed, and updated server info

            if new_repo.repo_type == 'git':

                git_repo = new_repo.scm_instance

                ScmModel().install_git_hooks(git_repo)

                # update repository server-info

                log.debug('Running update server info')

                git_repo._update_server_info()

            new_repo.update_changeset_cache()

        elif install_git_hooks:

            if db_repo.repo_type == 'git':

                ScmModel().install_git_hooks(db_repo.scm_instance, force=overwrite_git_hooks)

    removed = []

    # remove from database those repositories that are not in the filesystem

    for repo in sa.query(Repository).all():

        if repo.repo_name not in initial_repo_dict:

            if remove_obsolete:

                log.debug("Removing non-existing repository found in db `%s`",

                          repo.repo_name)

                try:

                    RepoModel().delete(repo, forks='detach', fs_remove=False)

                    sa.commit()

                except Exception:

                    #don't hold further removals on error

                    log.error(traceback.format_exc())

                    sa.rollback()

            removed.append(repo.repo_name)

    return added, removed

def load_extensions(root_path):

    try:

        ext = create_module('extensions', os.path.join(root_path, 'extensions.py'))

    except FileNotFoundError:

        try:

            ext = create_module('rc', os.path.join(root_path, 'rcextensions', '__init__.py'))

            log.warning('The name "rcextensions" is deprecated. Please use a file `extensions.py` instead of a directory `rcextensions`.')

        except FileNotFoundError:

            return

    log.info('Loaded Kallithea extensions from %s', ext)

    kallithea.EXTENSIONS = ext

    # Additional mappings that are not present in the pygments lexers

    kallithea.config.conf.LANGUAGES_EXTENSIONS_MAP.update(getattr(ext, 'EXTRA_MAPPINGS', {}))

    # Override any INDEX_EXTENSIONS

    if getattr(ext, 'INDEX_EXTENSIONS', []):

        log.debug('settings custom INDEX_EXTENSIONS')

        kallithea.config.conf.INDEX_EXTENSIONS = getattr(ext, 'INDEX_EXTENSIONS', [])

    # Additional INDEX_EXTENSIONS

    log.debug('adding extra into INDEX_EXTENSIONS')

    kallithea.config.conf.INDEX_EXTENSIONS.extend(getattr(ext, 'EXTRA_INDEX_EXTENSIONS', []))

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

# MISC

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

git_req_ver = StrictVersion('1.7.4')

def check_git_version():

    """

    Checks what version of git is installed on the system, and raise a system exit

    if it's too old for Kallithea to work properly.

    """

    if 'git' not in kallithea.BACKENDS:

        return None

    if not settings.GIT_EXECUTABLE_PATH:

        log.warning('No git executable configured - check "git_path" in the ini file.')

        return None

    try:

        stdout, stderr = GitRepository._run_git_command(['--version'])

    except RepositoryError as e:

        # message will already have been logged as error

        log.warning('No working git executable found - check "git_path" in the ini file.')

        return None

    if stderr:

        log.warning('Error/stderr from "%s --version":\n%s', settings.GIT_EXECUTABLE_PATH, safe_str(stderr))

    if not stdout:

        log.warning('No working git executable found - check "git_path" in the ini file.')

        return None

    output = safe_str(stdout).strip()

    m = re.search(r"\d+.\d+.\d+", output)

    if m:

        ver = StrictVersion(m.group(0))

        log.debug('Git executable: "%s", version %s (parsed from: "%s")',

                  settings.GIT_EXECUTABLE_PATH, ver, output)

        if ver < git_req_ver:

            log.error('Kallithea detected %s version %s, which is too old '

                      'for the system to function properly. '

                      'Please upgrade to version %s or later. '

                      'If you strictly need Mercurial repositories, you can '

                      'clear the "git_path" setting in the ini file.',

                      settings.GIT_EXECUTABLE_PATH, ver, git_req_ver)

            log.error("Terminating ...")

            sys.exit(1)

    else:

        ver = StrictVersion('0.0.0')

        log.warning('Error finding version number in "%s --version" stdout:\n%s',

                    settings.GIT_EXECUTABLE_PATH, output)

    return ver

            deltas[part] += length

            deltas[carry_part] -= 1

    # Same thing for days except that the increment depends on the (variable)

    # number of days in the month

    month_lengths = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

    if deltas['day'] < 0:

        if prevdate.month == 2 and (prevdate.year % 4 == 0 and

            (prevdate.year % 100 != 0 or prevdate.year % 400 == 0)

        ):

            deltas['day'] += 29

        else:

            deltas['day'] += month_lengths[prevdate.month - 1]

        deltas['month'] -= 1

    if deltas['month'] < 0:

        deltas['month'] += 12

        deltas['year'] -= 1

    # In short version, we want nicer handling of ages of more than a year

    if show_short_version:

        if deltas['year'] == 1:

            # ages between 1 and 2 years: show as months

            deltas['month'] += 12

            deltas['year'] = 0

        if deltas['year'] >= 2:

            # ages 2+ years: round

            if deltas['month'] > 6:

                deltas['year'] += 1

                deltas['month'] = 0

    # Format the result

    fmt_funcs = {

        'year': lambda d: ungettext('%d year', '%d years', d) % d,

        'month': lambda d: ungettext('%d month', '%d months', d) % d,

        'day': lambda d: ungettext('%d day', '%d days', d) % d,

        'hour': lambda d: ungettext('%d hour', '%d hours', d) % d,

        'minute': lambda d: ungettext('%d minute', '%d minutes', d) % d,

        'second': lambda d: ungettext('%d second', '%d seconds', d) % d,

    }

    for i, part in enumerate(order):

        value = deltas[part]

        if value == 0:

            continue

        if i < 5:

            sub_part = order[i + 1]

            sub_value = deltas[sub_part]

        else:

            sub_value = 0

        if sub_value == 0 or show_short_version:

            if future:

                return _('in %s') % fmt_funcs[part](value)

            else:

                return _('%s ago') % fmt_funcs[part](value)

        if future:

            return _('in %s and %s') % (fmt_funcs[part](value),

                fmt_funcs[sub_part](sub_value))

        else:

            return _('%s and %s ago') % (fmt_funcs[part](value),

                fmt_funcs[sub_part](sub_value))

    return _('just now')

def uri_filter(uri):

    """

    Removes user:password from given url string

    :param uri:

    :rtype: str

    :returns: filtered list of strings

    """

    if not uri:

        return []

    proto = ''

    for pat in ('https://', 'http://', 'git://'):

        if uri.startswith(pat):

            uri = uri[len(pat):]

            proto = pat

            break

    # remove passwords and username

    uri = uri[uri.find('@') + 1:]

    # get the port

    cred_pos = uri.find(':')

    if cred_pos == -1:

        host, port = uri, None

    else:

        host, port = uri[:cred_pos], uri[cred_pos + 1:]

    return [_f for _f in [proto, host, port] if _f]

def credentials_filter(uri):

    """

    Returns a url with removed credentials

    :param uri:

    """

    uri = uri_filter(uri)

    # check if we have port

    if len(uri) > 2 and uri[2]:

        uri[2] = ':' + uri[2]

    return ''.join(uri)

def get_clone_url(clone_uri_tmpl, prefix_url, repo_name, repo_id, username=None):

    parsed_url = urlobject.URLObject(prefix_url)

    prefix = urllib.parse.unquote(parsed_url.path.rstrip('/'))

    try:

        system_user = pwd.getpwuid(os.getuid()).pw_name

    except NameError: # TODO: support all systems - especially Windows

        system_user = 'kallithea' # hardcoded default value ...

    args = {

        'scheme': parsed_url.scheme,

        'user': urllib.parse.quote(username or ''),

        'netloc': parsed_url.netloc + prefix,  # like "hostname:port/prefix" (with optional ":port" and "/prefix")

        'prefix': prefix, # undocumented, empty or starting with /

        'repo': repo_name,

        'repoid': str(repo_id),

        'system_user': system_user,

        'hostname': parsed_url.hostname,

    }

    url = re.sub('{([^{}]+)}', lambda m: args.get(m.group(1), m.group(0)), clone_uri_tmpl)

    # remove leading @ sign if it's present. Case of empty user

    url_obj = urlobject.URLObject(url)

    if not url_obj.username:

        url_obj = url_obj.with_username(None)

    return str(url_obj)

def get_changeset_safe(repo, rev):

    """

    Safe version of get_changeset if this changeset doesn't exists for a

    repo it returns a Dummy one instead

    :param repo:

    :param rev:

    """

    if not isinstance(repo, BaseRepository):

        raise Exception('You must pass an Repository '

                        'object as first argument got %s' % type(repo))

    try:

        cs = repo.get_changeset(rev)

    except (RepositoryError, LookupError):

        cs = EmptyChangeset(requested_revision=rev)

    return cs

def datetime_to_time(dt):

    if dt:

        return time.mktime(dt.timetuple())

def time_to_datetime(tm):

    if tm:

        if isinstance(tm, str):

            try:

                tm = float(tm)

            except ValueError:

                return

        return datetime.datetime.fromtimestamp(tm)

# Must match regexp in kallithea/public/js/base.js MentionsAutoComplete()

# Check char before @ - it must not look like we are in an email addresses.

# Matching is greedy so we don't have to look beyond the end.

MENTIONS_REGEX = re.compile(r'(?:^|(?<=[^a-zA-Z0-9]))@([a-zA-Z0-9][-_.a-zA-Z0-9]*[a-zA-Z0-9])')

def extract_mentioned_usernames(text):

    r"""

    Returns list of (possible) usernames @mentioned in given text.

    >>> extract_mentioned_usernames('@1-2.a_X,@1234 not@not @ddd@not @n @ee @ff @gg, @gg;@hh @n\n@zz,')

    ['1-2.a_X', '1234', 'ddd', 'ee', 'ff', 'gg', 'gg', 'hh', 'zz']

    """

    return MENTIONS_REGEX.findall(text)

class AttributeDict(dict):

    def __getattr__(self, attr):

        return self.get(attr, None)

    __setattr__ = dict.__setitem__

    __delattr__ = dict.__delitem__

def obfuscate_url_pw(engine):

    try:

        _url = sa_url.make_url(engine or '')

    except ArgumentError:

        return engine

    if _url.password:

        _url.password = 'XXXXX'

    return str(_url)

class HookEnvironmentError(Exception): pass

def get_hook_environment():

    """

    Get hook context by deserializing the global KALLITHEA_EXTRAS environment

    variable.

    Called early in Git out-of-process hooks to get .ini config path so the

    basic environment can be configured properly. Also used in all hooks to get

    information about the action that triggered it.

    """

    try:

        kallithea_extras = os.environ['KALLITHEA_EXTRAS']

    except KeyError:

        raise HookEnvironmentError("Environment variable KALLITHEA_EXTRAS not found")

    extras = json.loads(kallithea_extras)

    for k in ['username', 'repository', 'scm', 'action', 'ip', 'config']:

        try:

            extras[k]

        except KeyError:

            raise HookEnvironmentError('Missing key %s in KALLITHEA_EXTRAS %s' % (k, extras))

    return AttributeDict(extras)

def set_hook_environment(username, ip_addr, repo_name, repo_alias, action=None):

    """Prepare global context for running hooks by serializing data in the

    global KALLITHEA_EXTRAS environment variable.

    Most importantly, this allow Git hooks to do proper logging and updating of

    caches after pushes.

    Must always be called before anything with hooks are invoked.

    """

    extras = {

        'ip': ip_addr, # used in log_push/pull_action action_logger

        'username': username,

        'action': action or 'push_local', # used in log_push_action_raw_ids action_logger

        'repository': repo_name,

        'scm': repo_alias, # used to pick hack in log_push_action_raw_ids

        'config': kallithea.CONFIG['__file__'], # used by git hook to read config

    }

    os.environ['KALLITHEA_EXTRAS'] = json.dumps(extras)

def get_current_authuser():

    """

    Gets kallithea user from threadlocal tmpl_context variable if it's

    defined, else returns None.

    """

    from tg import tmpl_context

    try:

        return getattr(tmpl_context, 'authuser', None)

    except TypeError:  # No object (name: context) has been registered for this thread

        return None

def urlreadable(s, _cleanstringsub=re.compile('[^-a-zA-Z0-9./]+').sub):

    return _cleanstringsub('_', s).rstrip('_')

def recursive_replace(str_, replace=' '):

    """

    Recursive replace of given sign to just one instance

    :param str_: given string

    :param replace: char to find and replace multiple instances

    Examples::

    >>> recursive_replace("Mighty---Mighty-Bo--sstones",'-')

    'Mighty-Mighty-Bo-sstones'

    """

    if str_.find(replace * 2) == -1:

        return str_

    else:

        str_ = str_.replace(replace * 2, replace)

        return recursive_replace(str_, replace)

def repo_name_slug(value):

    """

    Return slug of name of repository

    This function is called on each creation/modification

    of repository to prevent bad names in repo

    """

    slug = remove_formatting(value)

    slug = strip_tags(slug)

    for c in r"""`?=[]\;'"<>,/~!@#$%^&*()+{}|: """:

        slug = slug.replace(c, '-')

    slug = recursive_replace(slug, '-')

    slug = collapse(slug, '-')

    return slug

def ask_ok(prompt, retries=4, complaint='Yes or no please!'):

    while True:

        ok = input(prompt)

        if ok in ('y', 'ye', 'yes'):

            return True

        if ok in ('n', 'no', 'nop', 'nope'):

            return False

        retries = retries - 1

        if retries < 0:

            raise IOError

        print(complaint)

# -*- 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.model.comment

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

comments model for 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: Nov 11, 2011

:author: marcink

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

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

"""

import logging

from collections import defaultdict

from tg.i18n import ugettext as _

from kallithea.lib import helpers as h

from kallithea.model.db import ChangesetComment, PullRequest, Repository, User

from kallithea.model.meta import Session

from kallithea.model.notification import NotificationModel

log = logging.getLogger(__name__)

def _list_changeset_commenters(revision):

    return (Session().query(User)

        .join(ChangesetComment.author)

        .filter(ChangesetComment.revision == revision)

        .all())

def _list_pull_request_commenters(pull_request):

    return (Session().query(User)

        .join(ChangesetComment.author)

        .filter(ChangesetComment.pull_request_id == pull_request.pull_request_id)

        .all())

class ChangesetCommentsModel(object):

    def _get_notification_data(self, repo, comment, author, comment_text,

                               line_no=None, revision=None, pull_request=None,

                               status_change=None, closing_pr=False):

        """

        :returns: tuple (subj,body,recipients,notification_type,email_kwargs)

        """

        # make notification

        body = comment_text  # text of the comment

        line = ''

        if line_no:

            line = _('on line %s') % line_no

        # changeset

        if revision:

            notification_type = NotificationModel.TYPE_CHANGESET_COMMENT

            cs = repo.scm_instance.get_changeset(revision)

            desc = cs.short_id

            threading = ['%s-rev-%s@%s' % (repo.repo_name, revision, h.canonical_hostname())]

            if line_no: # TODO: url to file _and_ line number

                threading.append('%s-rev-%s-line-%s@%s' % (repo.repo_name, revision, line_no,

                                                           h.canonical_hostname()))

            comment_url = h.canonical_url('changeset_home',

                repo_name=repo.repo_name,

                revision=revision,

                anchor='comment-%s' % comment.comment_id)

            subj = h.link_to(

                'Re changeset: %(desc)s %(line)s' %

                          {'desc': desc, 'line': line},

                 comment_url)

            # get the current participants of this changeset

            recipients = _list_changeset_commenters(revision)

            # add changeset author if it's known locally

            cs_author = User.get_from_cs_author(cs.author)

            if not cs_author:

                # use repo owner if we cannot extract the author correctly

                # FIXME: just use committer name even if not a user

                cs_author = repo.owner

            recipients.append(cs_author)