:created_on: Apr 08, 2010

:author: marcink

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

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

"""

import os

import time

import logging

import datetime

import traceback

import hashlib

import collections

import functools

import sqlalchemy

from sqlalchemy import *

from sqlalchemy.ext.hybrid import hybrid_property

from sqlalchemy.orm import relationship, joinedload, class_mapper, validates

from beaker.cache import cache_region, region_invalidate

from webob.exc import HTTPNotFound

from pylons.i18n.translation import lazy_ugettext as _

from kallithea.lib.exceptions import DefaultUserException

from kallithea.lib.vcs import get_backend

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

from kallithea.lib.vcs.utils.lazy import LazyProperty

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

from kallithea.lib.utils2 import str2bool, safe_str, get_changeset_safe, \

    safe_unicode, remove_prefix, time_to_datetime, aslist, Optional, safe_int, \

    get_clone_url, urlreadable

from kallithea.lib.compat import json

from kallithea.lib.caching_query import FromCache

from kallithea.model.meta import Base, Session

URL_SEP = '/'

log = logging.getLogger(__name__)

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

# BASE CLASSES

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

_hash_key = lambda k: hashlib.md5(safe_str(k)).hexdigest()

    """

    Base Model for all classes

    """

    @classmethod

    def _get_keys(cls):

        """return column names for this model """

        return class_mapper(cls).c.keys()

    def get_dict(self):

        """

        return dict with keys and values corresponding

        to this model data """

        d = {}

        for k in self._get_keys():

            d[k] = getattr(self, k)

        # also use __json__() if present to get additional fields

        _json_attr = getattr(self, '__json__', None)

        if _json_attr:

            # update with attributes from __json__

            if callable(_json_attr):

                _json_attr = _json_attr()

            for k, val in _json_attr.iteritems():

                d[k] = val

        return d

    def get_appstruct(self):

        """return list with keys and values tuples corresponding

        to this model data """

        l = []

        for k in self._get_keys():

            l.append((k, getattr(self, k),))

        return l

    def populate_obj(self, populate_dict):

        """populate model with data from given populate_dict"""

        for k in self._get_keys():

            if k in populate_dict:

                setattr(self, k, populate_dict[k])

    @classmethod

    def query(cls):

        return Session().query(cls)

        if value is None:

            return None

        if isinstance(value, cls):

            return value

        if isinstance(value, (int, long)) or safe_str(value).isdigit():

            return cls.get(value)

        if callback is not None:

            return callback(value)

        raise Exception(

            'given object must be int, long or Instance of %s '

            'got %s, no callback provided' % (cls, type(value))

        )

    @classmethod

    def get_or_404(cls, id_):

        try:

            id_ = int(id_)

        except (TypeError, ValueError):

            raise HTTPNotFound

        res = cls.query().get(id_)

        if res is None:

            raise HTTPNotFound

        return res

    @classmethod

    def delete(cls, id_):

        obj = cls.query().get(id_)

        Session().delete(obj)

    def __repr__(self):

        if hasattr(self, '__unicode__'):

            # python repr needs to return str

            try:

                return safe_str(self.__unicode__())

            except UnicodeDecodeError:

                pass

        return '<DB:%s>' % (self.__class__.__name__)

_table_args_default_dict = {'extend_existing': True,

                            'mysql_engine': 'InnoDB',

                            'mysql_charset': 'utf8',

                            'sqlite_autoincrement': True,

                           }

    __tablename__ = 'settings'

    __table_args__ = (

        _table_args_default_dict,

    )

    SETTINGS_TYPES = {

        'str': safe_str,

        'int': safe_int,

        'unicode': safe_unicode,

        'bool': str2bool,

        'list': functools.partial(aslist, sep=',')

    }

    DEFAULT_UPDATE_URL = ''

    app_settings_id = Column(Integer(), primary_key=True)

    app_settings_name = Column(String(255), nullable=False, unique=True)

    _app_settings_value = Column("app_settings_value", Unicode(4096), nullable=False)

    _app_settings_type = Column("app_settings_type", String(255), nullable=True) # FIXME: not nullable?

    def __init__(self, key='', val='', type='unicode'):

        self.app_settings_name = key

        self.app_settings_value = val

        self.app_settings_type = type

    @validates('_app_settings_value')

    def validate_settings_value(self, key, val):

        assert type(val) == unicode

        return val

    @hybrid_property

    def app_settings_value(self):

        v = self._app_settings_value

        _type = self.app_settings_type

        converter = self.SETTINGS_TYPES.get(_type) or self.SETTINGS_TYPES['unicode']

        return converter(v)

    @app_settings_value.setter

    def app_settings_value(self, val):

        """

        Setter that will always make sure we use unicode in app_settings_value

        :param val:

        """

        self._app_settings_value = safe_unicode(val)

    @hybrid_property

    def app_settings_type(self):

        return self._app_settings_type

        return settings

    @classmethod

    def get_auth_plugins(cls, cache=False):

        auth_plugins = cls.get_by_name("auth_plugins").app_settings_value

        return auth_plugins

    @classmethod

    def get_auth_settings(cls, cache=False):

        ret = cls.query() \

                .filter(cls.app_settings_name.startswith('auth_')).all()

        fd = {}

        for row in ret:

            fd[row.app_settings_name] = row.app_settings_value

        return fd

    @classmethod

    def get_default_repo_settings(cls, cache=False, strip_prefix=False):

        ret = cls.query() \

                .filter(cls.app_settings_name.startswith('default_')).all()

        fd = {}

        for row in ret:

            key = row.app_settings_name

            if strip_prefix:

                key = remove_prefix(key, prefix='default_')

            fd.update({key: row.app_settings_value})

        return fd

    @classmethod

    def get_server_info(cls):

        import pkg_resources

        import platform

        import kallithea

        from kallithea.lib.utils import check_git_version

        mods = [(p.project_name, p.version) for p in pkg_resources.working_set]

        info = {

            'modules': sorted(mods, key=lambda k: k[0].lower()),

            'py_version': platform.python_version(),

            'platform': safe_unicode(platform.platform()),

            'kallithea_version': kallithea.__version__,

            'git_version': safe_unicode(check_git_version()),

            'git_path': kallithea.CONFIG.get('git_path')

        }

        return info

    __tablename__ = 'ui'

    __table_args__ = (

        # FIXME: ui_key as key is wrong and should be removed when the corresponding

        # Ui.get_by_key has been replaced by the composite key

        UniqueConstraint('ui_key'),

        UniqueConstraint('ui_section', 'ui_key'),

        _table_args_default_dict,

    )

    HOOK_UPDATE = 'changegroup.update'

    HOOK_REPO_SIZE = 'changegroup.repo_size'

    HOOK_PUSH = 'changegroup.push_logger'

    HOOK_PRE_PUSH = 'prechangegroup.pre_push'

    HOOK_PULL = 'outgoing.pull_logger'

    HOOK_PRE_PULL = 'preoutgoing.pre_pull'

    ui_id = Column(Integer(), primary_key=True)

    ui_section = Column(String(255), nullable=False)

    ui_key = Column(String(255), nullable=False)

    ui_value = Column(String(255), nullable=True) # FIXME: not nullable?

    ui_active = Column(Boolean(), nullable=False, default=True)

    @classmethod

    def get_by_key(cls, section, key):

        """ Return specified Ui object, or None if not found. """

        return cls.query().filter_by(ui_section=section, ui_key=key).scalar()

    @classmethod

    def get_or_create(cls, section, key):

        """ Return specified Ui object, creating it if necessary. """

        setting = cls.get_by_key(section, key)

        if setting is None:

            setting = cls(ui_section=section, ui_key=key)

            Session().add(setting)

        return setting

    @classmethod

    def get_builtin_hooks(cls):

        q = cls.query()

        q = q.filter(cls.ui_key.in_([cls.HOOK_UPDATE, cls.HOOK_REPO_SIZE,

                                     cls.HOOK_PUSH, cls.HOOK_PRE_PUSH,

                                     cls.HOOK_PULL, cls.HOOK_PRE_PULL]))

        q = q.filter(cls.ui_section == 'hooks')

        return q.all()

    @classmethod

    def get_custom_hooks(cls):

        q = cls.query()

        q = q.filter(~cls.ui_key.in_([cls.HOOK_UPDATE, cls.HOOK_REPO_SIZE,

                                      cls.HOOK_PUSH, cls.HOOK_PRE_PUSH,

                                      cls.HOOK_PULL, cls.HOOK_PRE_PULL]))

        q = q.filter(cls.ui_section == 'hooks')

        return q.all()

    @classmethod

    def get_repos_location(cls):

        return cls.get_by_key('paths', '/').ui_value

    @classmethod

    def create_or_update_hook(cls, key, val):

        new_ui = cls.get_or_create('hooks', key)

        new_ui.ui_active = True

        new_ui.ui_value = val

    def __repr__(self):

        return '<%s[%s]%s=>%s]>' % (self.__class__.__name__, self.ui_section,

                                    self.ui_key, self.ui_value)

    __tablename__ = 'users'

    __table_args__ = (

        Index('u_username_idx', 'username'),

        Index('u_email_idx', 'email'),

        _table_args_default_dict,

    )

    DEFAULT_USER = 'default'

    DEFAULT_GRAVATAR_URL = 'https://secure.gravatar.com/avatar/{md5email}?d=identicon&s={size}'

    # The name of the default auth type in extern_type, 'internal' lives in auth_internal.py

    DEFAULT_AUTH_TYPE = 'internal'

    user_id = Column(Integer(), primary_key=True)

    username = Column(String(255), nullable=False, unique=True)

    password = Column(String(255), nullable=False)

    active = Column(Boolean(), nullable=False, default=True)

    admin = Column(Boolean(), nullable=False, default=False)

    name = Column("firstname", Unicode(255), nullable=False)

    lastname = Column(Unicode(255), nullable=False)

    _email = Column("email", String(255), nullable=True, unique=True) # FIXME: not nullable?

    last_login = Column(DateTime(timezone=False), nullable=True)

    extern_type = Column(String(255), nullable=True) # FIXME: not nullable?

    extern_name = Column(String(255), nullable=True) # FIXME: not nullable?

    api_key = Column(String(255), nullable=False)

    inherit_default_permissions = Column(Boolean(), nullable=False, default=True)

    created_on = Column(DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    _user_data = Column("user_data", LargeBinary(), nullable=True)  # JSON data # FIXME: not nullable?

    user_log = relationship('UserLog')

    user_perms = relationship('UserToPerm', primaryjoin="User.user_id==UserToPerm.user_id", cascade='all')

    repositories = relationship('Repository')

    repo_groups = relationship('RepoGroup')

    user_groups = relationship('UserGroup')

    user_followers = relationship('UserFollowing', primaryjoin='UserFollowing.follows_user_id==User.user_id', cascade='all')

    followings = relationship('UserFollowing', primaryjoin='UserFollowing.user_id==User.user_id', cascade='all')

    repo_to_perm = relationship('UserRepoToPerm', primaryjoin='UserRepoToPerm.user_id==User.user_id', cascade='all')

    repo_group_to_perm = relationship('UserRepoGroupToPerm', primaryjoin='UserRepoGroupToPerm.user_id==User.user_id', cascade='all')

    group_member = relationship('UserGroupMember', cascade='all')

    notifications = relationship('UserNotification', cascade='all')

    # notifications assigned to this user

    user_created_notifications = relationship('Notification', cascade='all')

    # comments created by this user

    user_comments = relationship('ChangesetComment', cascade='all')

    #extra emails for this user

        """

        return ('%s %s (%s)' % (self.firstname, self.lastname, self.username)

                if (self.firstname and self.lastname) else self.username)

    @property

    def full_contact(self):

        return '%s %s <%s>' % (self.firstname, self.lastname, self.email)

    @property

    def short_contact(self):

        return '%s %s' % (self.firstname, self.lastname)

    @property

    def is_admin(self):

        return self.admin

    @property

    def AuthUser(self):

        """

        Returns instance of AuthUser for this user

        """

        from kallithea.lib.auth import AuthUser

        return AuthUser(dbuser=self)

    @hybrid_property

    def user_data(self):

        if not self._user_data:

            return {}

        try:

            return json.loads(self._user_data)

        except TypeError:

            return {}

    @user_data.setter

    def user_data(self, val):

        try:

            self._user_data = json.dumps(val)

        except Exception:

            log.error(traceback.format_exc())

    def __unicode__(self):

        return u"<%s('id:%s:%s')>" % (self.__class__.__name__,

                                      self.user_id, self.username)

    @classmethod

    def get_or_404(cls, id_, allow_default=True):

        '''

        the default user.

        '''

        user = super(User, cls).get_or_404(id_)

        if allow_default == False:

            if user.username == User.DEFAULT_USER:

                raise DefaultUserException

        return user

    @classmethod

    def get_by_username_or_email(cls, username_or_email, case_insensitive=False, cache=False):

        """

        For anything that looks like an email address, look up by the email address (matching

        case insensitively).

        For anything else, try to look up by the user name.

        This assumes no normal username can have '@' symbol.

        """

        if '@' in username_or_email:

            return User.get_by_email(username_or_email, cache=cache)

        else:

            return User.get_by_username(username_or_email, case_insensitive=case_insensitive, cache=cache)

    @classmethod

    def get_by_username(cls, username, case_insensitive=False, cache=False):

        if case_insensitive:

            q = cls.query().filter(func.lower(cls.username) == func.lower(username))

        else:

            q = cls.query().filter(cls.username == username)

        if cache:

            q = q.options(FromCache(

                            "sql_cache_short",

                            "get_user_%s" % _hash_key(username)

                          )

            )

        return q.scalar()

    @classmethod

    def get_by_api_key(cls, api_key, cache=False, fallback=True):

        if len(api_key) != 40 or not api_key.isalnum():

            return None

        q = cls.query().filter(cls.api_key == api_key)

        if cache:

            q = q.options(FromCache("sql_cache_short",

                                    "get_api_key_%s" % api_key))

        res = q.scalar()

        if user is None:

            raise Exception('Missing administrative account!')

        return user

    @classmethod

    def get_default_user(cls, cache=False):

        user = User.get_by_username(User.DEFAULT_USER, cache=cache)

        if user is None:

            raise Exception('Missing default account!')

        return user

    def get_api_data(self, details=False):

        """

        Common function for generating user related data for API

        """

        user = self

        data = dict(

            user_id=user.user_id,

            username=user.username,

            firstname=user.name,

            lastname=user.lastname,

            email=user.email,

            emails=user.emails,

            active=user.active,

            admin=user.admin,

        )

        if details:

            data.update(dict(

                extern_type=user.extern_type,

                extern_name=user.extern_name,

                api_key=user.api_key,

                api_keys=user.api_keys,

                last_login=user.last_login,

                ip_addresses=user.ip_addresses

                ))

        return data

    def __json__(self):

        data = dict(

            full_name=self.full_name,

            full_name_or_username=self.full_name_or_username,

            short_contact=self.short_contact,

            full_contact=self.full_contact

        )

        data.update(self.get_api_data())

        return data

    __tablename__ = 'user_api_keys'

    __table_args__ = (

        Index('uak_api_key_idx', 'api_key'),

        Index('uak_api_key_expires_idx', 'api_key', 'expires'),

        _table_args_default_dict,

    )

    __mapper_args__ = {}

    user_api_key_id = Column(Integer(), primary_key=True)

    user_id = Column(Integer(), ForeignKey('users.user_id'), nullable=False)

    api_key = Column(String(255), nullable=False, unique=True)

    description = Column(UnicodeText(), nullable=False)

    expires = Column(Float(53), nullable=False)

    created_on = Column(DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    user = relationship('User')

    @property

    def expired(self):

        if self.expires == -1:

            return False

        return time.time() > self.expires

    __tablename__ = 'user_email_map'

    __table_args__ = (

        Index('uem_email_idx', 'email'),

        _table_args_default_dict,

    )

    __mapper_args__ = {}

    email_id = Column(Integer(), primary_key=True)

    user_id = Column(Integer(), ForeignKey('users.user_id'), nullable=False)

    _email = Column("email", String(255), nullable=False, unique=True)

    user = relationship('User')

    @validates('_email')

    def validate_email(self, key, email):

        # check if this email is not main one

        main_email = Session().query(User).filter(User.email == email).scalar()

        if main_email is not None:

            raise AttributeError('email %s is present is user table' % email)

        return email

    @hybrid_property

    def email(self):

        return self._email

    @email.setter

    def email(self, val):

        self._email = val.lower() if val else None

    __tablename__ = 'user_ip_map'

    __table_args__ = (

        UniqueConstraint('user_id', 'ip_addr'),

        _table_args_default_dict,

    )

    __mapper_args__ = {}

    ip_id = Column(Integer(), primary_key=True)

    user_id = Column(Integer(), ForeignKey('users.user_id'), nullable=False)

    ip_addr = Column(String(255), nullable=False)

    active = Column(Boolean(), nullable=False, default=True)

    user = relationship('User')

    @classmethod

    def _get_ip_range(cls, ip_addr):

        from kallithea.lib import ipaddr

        net = ipaddr.IPNetwork(address=ip_addr)

        return [str(net.network), str(net.broadcast)]

    def __json__(self):

        return dict(

          ip_addr=self.ip_addr,

          ip_range=self._get_ip_range(self.ip_addr)

        )

    def __unicode__(self):

        return u"<%s('user_id:%s=>%s')>" % (self.__class__.__name__,

                                            self.user_id, self.ip_addr)

    __tablename__ = 'user_logs'

    __table_args__ = (

        _table_args_default_dict,

    )

    user_log_id = Column(Integer(), primary_key=True)

    user_id = Column(Integer(), ForeignKey('users.user_id'), nullable=True)

    username = Column(String(255), nullable=False)

    repository_id = Column(Integer(), ForeignKey('repositories.repo_id'), nullable=True)

    repository_name = Column(Unicode(255), nullable=False)

    user_ip = Column(String(255), nullable=True)

    action = Column(UnicodeText(), nullable=False)

    action_date = Column(DateTime(timezone=False), nullable=False)

    def __unicode__(self):

        return u"<%s('id:%s:%s')>" % (self.__class__.__name__,

                                      self.repository_name,

                                      self.action)

    @property

    def action_as_day(self):

        return datetime.date(*self.action_date.timetuple()[:3])

    user = relationship('User')

    repository = relationship('Repository', cascade='')

    __tablename__ = 'users_groups'

    __table_args__ = (

        _table_args_default_dict,

    )

    users_group_id = Column(Integer(), primary_key=True)

    users_group_name = Column(Unicode(255), nullable=False, unique=True)

    user_group_description = Column(Unicode(10000), nullable=True) # FIXME: not nullable?

    users_group_active = Column(Boolean(), nullable=False)

    inherit_default_permissions = Column("users_group_inherit_default_permissions", Boolean(), nullable=False, default=True)

    owner_id = Column('user_id', Integer(), ForeignKey('users.user_id'), nullable=False)

    created_on = Column(DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    _group_data = Column("group_data", LargeBinary(), nullable=True)  # JSON data # FIXME: not nullable?

    members = relationship('UserGroupMember', cascade="all, delete-orphan")

    users_group_to_perm = relationship('UserGroupToPerm', cascade='all')

    users_group_repo_to_perm = relationship('UserGroupRepoToPerm', cascade='all')

    users_group_repo_group_to_perm = relationship('UserGroupRepoGroupToPerm', cascade='all')

    user_user_group_to_perm = relationship('UserUserGroupToPerm ', cascade='all')

    user_group_user_group_to_perm = relationship('UserGroupUserGroupToPerm ', primaryjoin="UserGroupUserGroupToPerm.target_user_group_id==UserGroup.users_group_id", cascade='all')

    owner = relationship('User')

    @hybrid_property

    def group_data(self):

        if not self._group_data:

            return {}

        try:

            return json.loads(self._group_data)

        except TypeError:

            return {}

    @group_data.setter

    def group_data(self, val):

        try:

            self._group_data = json.dumps(val)

        except Exception:

            log.error(traceback.format_exc())

    def __unicode__(self):

        return u"<%s('id:%s:%s')>" % (self.__class__.__name__,

                                      self.users_group_id,

                                      self.users_group_name)

    @classmethod

    def get_by_group_name(cls, group_name, cache=False,

                          case_insensitive=False):

        if case_insensitive:

            q = cls.query().filter(func.lower(cls.users_group_name) == func.lower(group_name))

        else:

            q = cls.query().filter(cls.users_group_name == group_name)

        if cache:

            q = q.options(FromCache(

                            "sql_cache_short",

                            "get_group_%s" % _hash_key(group_name)

                          )

            )

        return q.scalar()

    @classmethod

    def get(cls, user_group_id, cache=False):

        user_group = cls.query()

        if cache:

            user_group = user_group.options(FromCache("sql_cache_short",

                                    "get_users_group_%s" % user_group_id))

        return user_group.get(user_group_id)

    def get_api_data(self, with_members=True):

        user_group = self

        data = dict(

            users_group_id=user_group.users_group_id,

            group_name=user_group.users_group_name,

            group_description=user_group.user_group_description,

            active=user_group.users_group_active,

            owner=user_group.owner.username,

        )

        if with_members:

            members = []

            for user in user_group.members:

                user = user.user

                members.append(user.get_api_data())

            data['members'] = members

        return data

    __tablename__ = 'users_groups_members'

    __table_args__ = (

        _table_args_default_dict,

    )

    users_group_member_id = Column(Integer(), primary_key=True)

    users_group_id = Column(Integer(), ForeignKey('users_groups.users_group_id'), nullable=False)

    user_id = Column(Integer(), ForeignKey('users.user_id'), nullable=False)

    user = relationship('User')

    users_group = relationship('UserGroup')

    def __init__(self, gr_id='', u_id=''):

        self.users_group_id = gr_id

        self.user_id = u_id

    __tablename__ = 'repositories_fields'

    __table_args__ = (

        UniqueConstraint('repository_id', 'field_key'),  # no-multi field

        _table_args_default_dict,

    )

    PREFIX = 'ex_'  # prefix used in form to not conflict with already existing fields

    repo_field_id = Column(Integer(), primary_key=True)

    repository_id = Column(Integer(), ForeignKey('repositories.repo_id'), nullable=False)

    field_key = Column(String(250), nullable=False)

    field_label = Column(String(1024), nullable=False)

    field_value = Column(String(10000), nullable=False)

    field_desc = Column(String(1024), nullable=False)

    field_type = Column(String(255), nullable=False)

    created_on = Column(DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    repository = relationship('Repository')

    @property

    def field_key_prefixed(self):

        return 'ex_%s' % self.field_key

    @classmethod

    def un_prefix_key(cls, key):

        if key.startswith(cls.PREFIX):

            return key[len(cls.PREFIX):]

        return key

    @classmethod

    def get_by_key_name(cls, key, repo):

        row = cls.query() \

                .filter(cls.repository == repo) \

                .filter(cls.field_key == key).scalar()

        return row

    __tablename__ = 'repositories'

    __table_args__ = (

        Index('r_repo_name_idx', 'repo_name'),

        _table_args_default_dict,

    )

    DEFAULT_CLONE_URI = '{scheme}://{user}@{netloc}/{repo}'

    DEFAULT_CLONE_URI_ID = '{scheme}://{user}@{netloc}/_{repoid}'

    STATE_CREATED = u'repo_state_created'

    STATE_PENDING = u'repo_state_pending'

    STATE_ERROR = u'repo_state_error'

    repo_id = Column(Integer(), primary_key=True)

    repo_name = Column(Unicode(255), nullable=False, unique=True)

    repo_state = Column(String(255), nullable=False)

    clone_uri = Column(String(255), nullable=True) # FIXME: not nullable?

    repo_type = Column(String(255), nullable=False)

    owner_id = Column('user_id', Integer(), ForeignKey('users.user_id'), nullable=False)

    private = Column(Boolean(), nullable=False)

    enable_statistics = Column("statistics", Boolean(), nullable=False, default=True)

    enable_downloads = Column("downloads", Boolean(), nullable=False, default=True)

    description = Column(Unicode(10000), nullable=False)

    created_on = Column(DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    updated_on = Column(DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    _landing_revision = Column("landing_revision", String(255), nullable=False)

    enable_locking = Column(Boolean(), nullable=False, default=False)

    _locked = Column("locked", String(255), nullable=True) # FIXME: not nullable?

    _changeset_cache = Column("changeset_cache", LargeBinary(), nullable=True) # JSON data # FIXME: not nullable?

    fork_id = Column(Integer(), ForeignKey('repositories.repo_id'), nullable=True)

    group_id = Column(Integer(), ForeignKey('groups.group_id'), nullable=True)

    owner = relationship('User')

    fork = relationship('Repository', remote_side=repo_id)

    group = relationship('RepoGroup')

    repo_to_perm = relationship('UserRepoToPerm', cascade='all', order_by='UserRepoToPerm.repo_to_perm_id')

    users_group_to_perm = relationship('UserGroupRepoToPerm', cascade='all')

    stats = relationship('Statistics', cascade='all', uselist=False)

    followers = relationship('UserFollowing',

                             primaryjoin='UserFollowing.follows_repo_id==Repository.repo_id',

                             cascade='all')

    extra_fields = relationship('RepositoryField',

                                cascade="all, delete-orphan")

    logs = relationship('UserLog')

    def set_invalidate(self):

        """

        Mark caches of this repo as invalid.

        """

        CacheInvalidation.set_invalidate(self.repo_name)

    _scm_instance = None

    @property

    def scm_instance(self):

        if self._scm_instance is None:

            self._scm_instance = self.scm_instance_cached()

        return self._scm_instance

    def scm_instance_cached(self, valid_cache_keys=None):

        @cache_region('long_term', 'scm_instance_cached')

        def _c(repo_name): # repo_name is just for the cache key

            log.debug('Creating new %s scm_instance and populating cache', repo_name)

            return self.scm_instance_no_cache()

        rn = self.repo_name

        valid = CacheInvalidation.test_and_set_valid(rn, None, valid_cache_keys=valid_cache_keys)

        if not valid:

            log.debug('Cache for %s invalidated, getting new object', rn)

            region_invalidate(_c, None, 'scm_instance_cached', rn)

        else:

            log.debug('Trying to get scm_instance of %s from cache', rn)

        return _c(rn)

    def scm_instance_no_cache(self):

        repo_full_path = safe_str(self.repo_full_path)

        alias = get_scm(repo_full_path)[0]

        log.debug('Creating instance of %s repository from %s',

                  alias, self.repo_full_path)

        backend = get_backend(alias)

        if alias == 'hg':

            repo = backend(repo_full_path, create=False,

                           baseui=self._ui)

        else:

            repo = backend(repo_full_path, create=False)

        return repo