backend.tracim_backend.models.data

Complexity

Total Complexity

236

Size/Duplication

Total Lines	1518
Duplicated Lines	1.58 %

Importance

Changes

0

80 Methods

Rating	Name	Duplication	Size	Complexity
A	Content.get_current_revision()	0	11	4
A	Content.properties()	0	12	1
A	Content.new_revision()	0	14	2
B	Content.get_child_nb()	0	9	6
A	Content.datetime_as_delta()	0	6	2
A	Content.depot_file()	0	3	1
A	Content.is_readonly()	0	3	1
B	Content.get_valid_children()	0	5	6
A	Content.created_as_delta()	0	6	2
A	Content.get_label()	0	2	1
A	Content.is_active()	0	3	1
A	UserRoleInWorkspace.role_as_label()	0	2	1
B	ContentRevisionRO.copy()	0	28	5
A	Content.type()	0	3	1
A	UserRoleInWorkspace.get_all_role_values()	0	6	1
A	Content.get_previous_revision()	0	12	4
A	ContentRevisionRO.get_last_action()	0	2	1
A	Content.owner_id()	0	3	1
A	Content.description()	0	3	1
A	Content.file_mimetype()	0	3	1
A	UserRoleInWorkspace.role_object()	0	2	1
A	Content.copy()	0	6	2
A	ContentRevisionRO.has_new_information_for()	0	13	3
A	Content.get_status()	0	2	1
A	Content.label()	0	3	1
A	Content.revision_type()	0	3	1
A	VirtualEvent.__init__()	0	10	1
A	Content.parent_id()	0	3	1
A	Content.file_name()	0	3	1
A	Content.is_deleted()	0	3	1
A	Content.is_temporary()	0	3	1
A	Content.has_new_information_for()	0	20	5
A	ContentRevisionRO.new_from()	0	27	3
C	ContentChecker.check_properties()	0	23	11
A	Content.created()	0	3	1
A	Content.description_as_raw_text()	0	4	1
A	Content.revision_id()	0	3	1
A	ContentRevisionRO.__setattr__()	0	20	5
A	Content.content_id()	0	3	1
A	VirtualEvent.create_from_content_revision()	0	11	1
A	Content.get_last_action()	0	2	1
A	Content.children()	0	13	2
A	VirtualEvent.create_from_content()	0	17	2
A	Content.get_last_activity_date()	0	14	5
A	ContentRevisionRO.file_name()	0	5	1
A	Content.first_revision()	0	3	1
A	Content.parent()	0	3	1
A	Content.revision()	0	3	1
A	Workspace.get_label()	0	3	1
A	Content.node()	0	3	1
A	ContentRevisionRO.is_readonly()	0	3	1
A	ContentRevisionRO.is_active()	0	3	1
A	UserRoleInWorkspace.get_all_role_slug()	0	9	1
A	Content.get_allowed_content_types()	0	17	4
A	Content.get_comments()	0	6	5
A	ContentRevisionRO.get_label()	0	2	1
A	Workspace.contents()	0	11	4
A	Content.get_last_comment_from()	0	12	5
A	Content.updated()	0	3	1
A	Content.format_path()	0	7	1
A	ActionDescription.allowed_values()	0	13	1
A	Content.last_revision()	0	3	1
D	VirtualEvent.create_readable_date()	24	24	13
C	Content.get_history()	0	23	10
A	VirtualEvent.created_as_delta()	0	5	2
A	Content.workspace_id()	0	3	1
A	Workspace.get_allowed_content_types()	0	3	1
C	Workspace.get_valid_children()	0	13	9
A	Content.status()	0	3	1
A	Content.workspace()	0	3	1
A	Content.owner()	0	3	1
A	Content.get_simple_last_activity_date()	0	11	3
A	VirtualEvent.create_from()	0	6	3
A	Content.file_extension()	0	3	1
A	Workspace.get_user_role()	0	5	3
A	Content._properties()	0	3	1
A	NodeTreeItem.__init__()	0	9	1
A	Content.is_archived()	0	3	1
A	ContentRevisionRO.get_status()	0	5	2
A	ActionDescription.__init__()	0	8	1

# -*- coding: utf-8 -*-
import datetime as datetime_root
import json
import os
import typing
from datetime import datetime

from babel.dates import format_timedelta
from bs4 import BeautifulSoup
from depot.fields.sqlalchemy import UploadedFileField
from depot.fields.upload import UploadedFile
from depot.io.utils import FileIntent
from sqlalchemy import Column
from sqlalchemy import ForeignKey
from sqlalchemy import Index
from sqlalchemy import Sequence
from sqlalchemy import inspect
from sqlalchemy.ext.associationproxy import association_proxy
from sqlalchemy.ext.hybrid import hybrid_property
from sqlalchemy.orm import backref
from sqlalchemy.orm import relationship
from sqlalchemy.orm.attributes import InstrumentedAttribute
from sqlalchemy.orm.collections import attribute_mapped_collection
from sqlalchemy.types import Boolean
from sqlalchemy.types import DateTime
from sqlalchemy.types import Integer
from sqlalchemy.types import Text
from sqlalchemy.types import Unicode

from tracim_backend.app_models.contents import ContentStatus
from tracim_backend.app_models.contents import content_status_list
from tracim_backend.app_models.contents import content_type_list
from tracim_backend.exceptions import ContentRevisionUpdateError
from tracim_backend.exceptions import ContentStatusNotExist
from tracim_backend.lib.utils.translation import Translator
from tracim_backend.lib.utils.translation import get_locale
from tracim_backend.models.auth import User
from tracim_backend.models.meta import DeclarativeBase
from tracim_backend.models.roles import WorkspaceRoles


class Workspace(DeclarativeBase):

    __tablename__ = 'workspaces'

    workspace_id = Column(Integer, Sequence('seq__workspaces__workspace_id'), autoincrement=True, primary_key=True)

    # TODO - G.M - 2018-10-30 - Make workspace label unique
    # Uniqueness of label is only check in high level when workspace is created,
    # we should be sure at database level that workspace label are unique
    # nb: be careful about mysql compat with long unicode, forcing utf8 charset
    # for mysql will probably be needed, see fix in User sqlalchemy object
    label = Column(Unicode(1024), unique=False, nullable=False, default='')
    description = Column(Text(), unique=False, nullable=False, default='')
    calendar_enabled = Column(Boolean, unique=False, nullable=False, default=False)

    #  Default value datetime.utcnow,
    # see: http://stackoverflow.com/a/13370382/801924 (or http://pastebin.com/VLyWktUn)
    created = Column(DateTime, unique=False, nullable=False, default=datetime.utcnow)
    #  Default value datetime.utcnow,
    # see: http://stackoverflow.com/a/13370382/801924 (or http://pastebin.com/VLyWktUn)
    updated = Column(DateTime, unique=False, nullable=False, default=datetime.utcnow)

    is_deleted = Column(Boolean, unique=False, nullable=False, default=False)

    revisions = relationship("ContentRevisionRO")

    @hybrid_property
    def contents(self) -> ['Content']:
        # Return a list of unique revisions parent content
        contents = []
        for revision in self.revisions:
            # TODO BS 20161209: This ``revision.node.workspace`` make a lot
            # of SQL queries !
            if revision.node.workspace == self and revision.node not in contents:
                contents.append(revision.node)

        return contents

    # TODO - G-M - 27-03-2018 - [Calendar] Replace this in context model object
    # @property
    # def calendar_url(self) -> str:
    #     # TODO - 20160531 - Bastien: Cyclic import if import in top of file
    #     from tracim.lib.calendar import CalendarManager
    #     calendar_manager = CalendarManager(None)
    #
    #     return calendar_manager.get_workspace_calendar_url(self.workspace_id)

    def get_user_role(self, user: User) -> int:
        for role in user.roles:
            if role.workspace.workspace_id==self.workspace_id:
                return role.role
        return UserRoleInWorkspace.NOT_APPLICABLE

    def get_label(self):
        """ this method is for interoperability with Content class"""
        return self.label

    def get_allowed_content_types(self):
        # @see Content.get_allowed_content_types()
        return content_type_list.endpoint_allowed_types_slug()

    def get_valid_children(
            self,
            content_types: list=None,
            show_deleted: bool=False,
            show_archived: bool=False,
    ):
        for child in self.contents:
            # we search only direct children
            if not child.parent \
                    and (show_deleted or not child.is_deleted) \
                    and (show_archived or not child.is_archived):
                if not content_types or child.type in content_types:
                    yield child


class UserRoleInWorkspace(DeclarativeBase):

    __tablename__ = 'user_workspace'

    user_id = Column(Integer, ForeignKey('users.user_id'), nullable=False, default=None, primary_key=True)
    workspace_id = Column(Integer, ForeignKey('workspaces.workspace_id'), nullable=False, default=None, primary_key=True)
    role = Column(Integer, nullable=False, default=0, primary_key=False)
    do_notify = Column(Boolean, unique=False, nullable=False, default=False)

    workspace = relationship('Workspace', remote_side=[Workspace.workspace_id], backref='roles', lazy='joined')
    user = relationship('User', remote_side=[User.user_id], backref='roles')

    NOT_APPLICABLE = WorkspaceRoles.NOT_APPLICABLE.level
    READER = WorkspaceRoles.READER.level
    CONTRIBUTOR = WorkspaceRoles.CONTRIBUTOR.level
    CONTENT_MANAGER = WorkspaceRoles.CONTENT_MANAGER.level
    WORKSPACE_MANAGER = WorkspaceRoles.WORKSPACE_MANAGER.level

    # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
    # SLUG = {
    #     NOT_APPLICABLE: 'not-applicable',
    #     READER: 'reader',
    #     CONTRIBUTOR: 'contributor',
    #     CONTENT_MANAGER: 'content-manager',
    #     WORKSPACE_MANAGER: 'workspace-manager',
    # }

    # LABEL = dict()
    # LABEL[0] = l_('N/A')
    # LABEL[1] = l_('Reader')
    # LABEL[2] = l_('Contributor')
    # LABEL[4] = l_('Content Manager')
    # LABEL[8] = l_('Workspace Manager')
    # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
    #
    # STYLE = dict()
    # STYLE[0] = ''
    # STYLE[1] = 'color: #1fdb11;'
    # STYLE[2] = 'color: #759ac5;'
    # STYLE[4] = 'color: #ea983d;'
    # STYLE[8] = 'color: #F00;'
    #
    # ICON = dict()
    # ICON[0] = ''
    # ICON[1] = 'fa-eye'
    # ICON[2] = 'fa-pencil'
    # ICON[4] = 'fa-graduation-cap'
    # ICON[8] = 'fa-legal'
    #
    #
    # @property
    # def fa_icon(self):
    #     return UserRoleInWorkspace.ICON[self.role]
    #
    # @property
    # def style(self):
    #     return UserRoleInWorkspace.STYLE[self.role]
    #

    def role_object(self):
        return WorkspaceRoles.get_role_from_level(level=self.role)

    def role_as_label(self):
        return self.role_object().label

    @classmethod
    def get_all_role_values(cls) -> typing.List[int]:
        """
        Return all valid role value
        """
        return [role.level for role in WorkspaceRoles.get_all_valid_role()]

    @classmethod
    def get_all_role_slug(cls) -> typing.List[str]:
        """
        Return all valid role slug
        """
        # INFO - G.M - 25-05-2018 - Be carefull, as long as this method
        # and get_all_role_values are both used for API, this method should
        # return item in the same order as get_all_role_values
        return [role.slug for role in WorkspaceRoles.get_all_valid_role()]

# TODO - G.M - 10-04-2018 - [Cleanup] Drop this
# class RoleType(object):
#     def __init__(self, role_id):
#         self.role_type_id = role_id
        # self.fa_icon = UserRoleInWorkspace.ICON[role_id]
        # self.role_label = UserRoleInWorkspace.LABEL[role_id]
        # self.css_style = UserRoleInWorkspace.STYLE[role_id]


# TODO - G.M - 09-04-2018 [Cleanup] It this items really needed ?
# class LinkItem(object):
#     def __init__(self, href, label):
#         self.href = href
#        self.label = label


class ActionDescription(object):
    """
    Allowed status are:
    - open
    - closed-validated
    - closed-invalidated
    - closed-deprecated
    """

    COPY = 'copy'
    ARCHIVING = 'archiving'
    COMMENT = 'content-comment'
    CREATION = 'creation'
    DELETION = 'deletion'
    EDITION = 'edition' # Default action if unknow
    REVISION = 'revision'
    STATUS_UPDATE = 'status-update'
    UNARCHIVING = 'unarchiving'
    UNDELETION = 'undeletion'
    MOVE = 'move'

    # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
    _ICONS = {
        'archiving': 'archive',
        'content-comment': 'comment-o',
        'creation': 'magic',
        'deletion': 'trash',
        'edition': 'edit',
        'revision': 'history',
        'status-update': 'random',
        'unarchiving': 'file-archive-o',
        'undeletion': 'trash-o',
        'move': 'arrows',
        'copy': 'files-o',
    }
    #
    # _LABELS = {
    #     'archiving': l_('archive'),
    #     'content-comment': l_('Item commented'),
    #     'creation': l_('Item created'),
    #     'deletion': l_('Item deleted'),
    #     'edition': l_('item modified'),
    #     'revision': l_('New revision'),
    #     'status-update': l_('New status'),
    #     'unarchiving': l_('Item unarchived'),
    #     'undeletion': l_('Item undeleted'),
    #     'move': l_('Item moved'),
    #     'copy': l_('Item copied'),
    # }

    def __init__(self, id):
        assert id in ActionDescription.allowed_values()
        self.id = id
        # FIXME - G.M - 17-04-2018 - Label and fa_icon needed for webdav
        #  design template,
        # find a way to not rely on this.
        self.label = self.id
        self.fa_icon = ActionDescription._ICONS[id]
        #self.icon = self.fa_icon
        # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
        # self.label = ActionDescription._LABELS[id]

        # self.css = ''

    @classmethod
    def allowed_values(cls):
        return [cls.ARCHIVING,
                cls.COMMENT,
                cls.CREATION,
                cls.DELETION,
                cls.EDITION,
                cls.REVISION,
                cls.STATUS_UPDATE,
                cls.UNARCHIVING,
                cls.UNDELETION,
                cls.MOVE,
                cls.COPY,
                ]


# TODO - G.M - 30-05-2018 - Drop this old code when whe are sure nothing
# is lost .


# class ContentStatus(object):
#     """
#     Allowed status are:
#     - open
#     - closed-validated
#     - closed-invalidated
#     - closed-deprecated
#     """
#
#     OPEN = 'open'
#     CLOSED_VALIDATED = 'closed-validated'
#     CLOSED_UNVALIDATED = 'closed-unvalidated'
#     CLOSED_DEPRECATED = 'closed-deprecated'
#
#     # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
#     # _LABELS = {'open': l_('work in progress'),
#     #            'closed-validated': l_('closed — validated'),
#     #            'closed-unvalidated': l_('closed — cancelled'),
#     #            'closed-deprecated': l_('deprecated')}
#     #
#     # _LABELS_THREAD = {'open': l_('subject in progress'),
#     #                   'closed-validated': l_('subject closed — resolved'),
#     #                   'closed-unvalidated': l_('subject closed — cancelled'),
#     #                   'closed-deprecated': l_('deprecated')}
#     #
#     # _LABELS_FILE = {'open': l_('work in progress'),
#     #                 'closed-validated': l_('closed — validated'),
#     #                 'closed-unvalidated': l_('closed — cancelled'),
#     #                 'closed-deprecated': l_('deprecated')}
#     #
#     # _ICONS = {
#     #     'open': 'fa fa-square-o',
#     #     'closed-validated': 'fa fa-check-square-o',
#     #     'closed-unvalidated': 'fa fa-close',
#     #     'closed-deprecated': 'fa fa-warning',
#     # }
#     #
#     # _CSS = {
#     #     'open': 'tracim-status-open',
#     #     'closed-validated': 'tracim-status-closed-validated',
#     #     'closed-unvalidated': 'tracim-status-closed-unvalidated',
#     #     'closed-deprecated': 'tracim-status-closed-deprecated',
#     # }
#
#     def __init__(self,
#                  id,
#                  # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
#                  # type=''
#     ):
#         self.id = id
#         # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
#         # self.icon = ContentStatus._ICONS[id]
#         # self.css = ContentStatus._CSS[id]
#         #
#         # if type==content_type_list.Thread.slug:
#         #     self.label = ContentStatus._LABELS_THREAD[id]
#         # elif type==content_type_list.File.slug:
#         #     self.label = ContentStatus._LABELS_FILE[id]
#         # else:
#         #     self.label = ContentStatus._LABELS[id]
#
#
#     @classmethod
#     def all(cls, type='') -> ['ContentStatus']:
#         # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
#         # all = []
#         # all.append(ContentStatus('open', type))
#         # all.append(ContentStatus('closed-validated', type))
#         # all.append(ContentStatus('closed-unvalidated', type))
#         # all.append(ContentStatus('closed-deprecated', type))
#         # return all
#         status_list = list()
#         for elem in cls.allowed_values():
#             status_list.append(ContentStatus(elem))
#         return status_list
#
#     @classmethod
#     def allowed_values(cls):
#         # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
#         # return ContentStatus._LABELS.keys()
#         return [
#             ContentStatus.OPEN,
#             ContentStatus.CLOSED_UNVALIDATED,
#             ContentStatus.CLOSED_VALIDATED,
#             ContentStatus.CLOSED_DEPRECATED
#         ]


# class ContentType(object):
#     Any = 'any'
#
#     Folder = 'folder'
#     File = 'file'
#     Comment = 'comment'
#     Thread = 'thread'
#     Page = 'page'
#     Event = 'event'
#
#     # TODO - G.M - 10-04-2018 - [Cleanup] Do we really need this ?
#     # _STRING_LIST_SEPARATOR = ','
#
#     # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
#     # _ICONS = {  # Deprecated
#     #     'dashboard': 'fa-home',
#     #     'workspace': 'fa-bank',
#     #     'folder': 'fa fa-folder-open-o',
#     #     'file': 'fa fa-paperclip',
#     #     'page': 'fa fa-file-text-o',
#     #     'thread': 'fa fa-comments-o',
#     #     'comment': 'fa fa-comment-o',
#     #     'event': 'fa fa-calendar-o',
#     # }
#     #
#     # _CSS_ICONS = {
#     #     'dashboard': 'fa fa-home',
#     #     'workspace': 'fa fa-bank',
#     #     'folder': 'fa fa-folder-open-o',
#     #     'file': 'fa fa-paperclip',
#     #     'page': 'fa fa-file-text-o',
#     #     'thread': 'fa fa-comments-o',
#     #     'comment': 'fa fa-comment-o',
#     #     'event': 'fa fa-calendar-o',
#     # }
#     #
#     # _CSS_COLORS = {
#     #     'dashboard': 't-dashboard-color',
#     #     'workspace': 't-less-visible',
#     #     'folder': 't-folder-color',
#     #     'file': 't-file-color',
#     #     'page': 't-page-color',
#     #     'thread': 't-thread-color',
#     #     'comment': 't-thread-color',
#     #     'event': 't-event-color',
#     # }
#
#     _ORDER_WEIGHT = {
#         'folder': 0,
#         'page': 1,
#         'thread': 2,
#         'file': 3,
#         'comment': 4,
#         'event': 5,
#     }
#
#     # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
#     # _LABEL = {
#     #     'dashboard': '',
#     #     'workspace': l_('workspace'),
#     #     'folder': l_('folder'),
#     #     'file': l_('file'),
#     #     'page': l_('page'),
#     #     'thread': l_('thread'),
#     #     'comment': l_('comment'),
#     #     'event': l_('event'),
#     # }
#     #
#     # _DELETE_LABEL = {
#     #     'dashboard': '',
#     #     'workspace': l_('Delete this workspace'),
#     #     'folder': l_('Delete this folder'),
#     #     'file': l_('Delete this file'),
#     #     'page': l_('Delete this page'),
#     #     'thread': l_('Delete this thread'),
#     #     'comment': l_('Delete this comment'),
#     #     'event': l_('Delete this event'),
#     # }
#     #
#     # @classmethod
#     # def get_icon(cls, type: str):
#     #     assert(type in ContentType._ICONS) # DYN_REMOVE
#     #     return ContentType._ICONS[type]
#
#     @classmethod
#     def all(cls):
#         return cls.allowed_types()
#
#     @classmethod
#     def allowed_types(cls):
#         return [cls.Folder, cls.File, cls.Comment, cls.Thread, cls.Page,
#                 cls.Event]
#
#     @classmethod
#     def allowed_types_for_folding(cls):
#         # This method is used for showing only "main"
#         # types in the left-side treeview
#         return [cls.Folder, cls.File, cls.Thread, cls.Page]
#
#     # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
#     # @classmethod
#     # def allowed_types_from_str(cls, allowed_types_as_string: str):
#     #     allowed_types = []
#     #     # HACK - THIS
#     #     for item in allowed_types_as_string.split(ContentType._STRING_LIST_SEPARATOR):
#     #         if item and item in ContentType.allowed_types_for_folding():
#     #             allowed_types.append(item)
#     #     return allowed_types
#     #
#     # @classmethod
#     # def fill_url(cls, content: 'Content'):
#     #     # TODO - DYNDATATYPE - D.A. - 2014-12-02
#     #     # Make this code dynamic loading data types
#     #
#     #     if content.type==content_type_list.Folder.slug:
#     #         return '/workspaces/{}/folders/{}'.format(content.workspace_id, content.content_id)
#     #     elif content.type==content_type_list.File.slug:
#     #         return '/workspaces/{}/folders/{}/files/{}'.format(content.workspace_id, content.parent_id, content.content_id)
#     #     elif content.type==content_type_list.Thread.slug:
#     #         return '/workspaces/{}/folders/{}/threads/{}'.format(content.workspace_id, content.parent_id, content.content_id)
#     #     elif content.type==content_type_list.Page.slug:
#     #         return '/workspaces/{}/folders/{}/pages/{}'.format(content.workspace_id, content.parent_id, content.content_id)
#     #
#     # @classmethod
#     # def fill_url_for_workspace(cls, workspace: Workspace):
#     #     # TODO - DYNDATATYPE - D.A. - 2014-12-02
#     #     # Make this code dynamic loading data types
#     #     return '/workspaces/{}'.format(workspace.workspace_id)
#
#     @classmethod
#     def sorted(cls, types: ['ContentType']) -> ['ContentType']:
#         return sorted(types, key=lambda content_type: content_type.priority)
#
#     @property
#     def type(self):
#         return self.id
#
#     def __init__(self, type):
#         self.id = type
#         # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
#         # self.icon = ContentType._CSS_ICONS[type]
#         # self.color = ContentType._CSS_COLORS[type]  # deprecated
#         # self.css = ContentType._CSS_COLORS[type]
#         # self.label = ContentType._LABEL[type]
#         self.priority = ContentType._ORDER_WEIGHT[type]
#
#     def toDict(self):
#         return dict(id=self.type,
#                     type=self.type,
#                     # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
#                     # icon=self.icon,
#                     # color=self.color,
#                     # label=self.label,
#                     priority=self.priority)

class ContentChecker(object):

    @classmethod
    def check_properties(cls, item):
        properties = item.properties
        if item.type == content_type_list.Event.slug:
            if 'name' not in properties.keys():
                return False
            if 'raw' not in properties.keys():
                return False
            if 'start' not in properties.keys():
                return False
            if 'end' not in properties.keys():
                return False
            return True
        else:
            if 'allowed_content' in properties.keys():
                for content_slug, value in properties['allowed_content'].items():  # nopep8
                    if not isinstance(value, bool):
                        return False
                    if not content_slug in content_type_list.endpoint_allowed_types_slug():  # nopep8
                        return False
            if 'origin' in properties.keys():
                pass
            return True


class ContentRevisionRO(DeclarativeBase):
    """
    Revision of Content. It's immutable, update or delete an existing ContentRevisionRO will throw
    ContentRevisionUpdateError errors.
    """

    __tablename__ = 'content_revisions'

    revision_id = Column(Integer, primary_key=True)
    content_id = Column(Integer, ForeignKey('content.id'), nullable=False)
    # TODO - G.M - 2018-06-177 - [author] Owner should be renamed "author"
    owner_id = Column(Integer, ForeignKey('users.user_id'), nullable=True)

    label = Column(Unicode(1024), unique=False, nullable=False)
    description = Column(Text(), unique=False, nullable=False, default='')
    file_extension = Column(
        Unicode(255),
        unique=False,
        nullable=False,
        server_default='',
    )
    file_mimetype = Column(Unicode(255),  unique=False, nullable=False, default='')
    # INFO - A.P - 2017-07-03 - Depot Doc
    # http://depot.readthedocs.io/en/latest/#attaching-files-to-models
    # http://depot.readthedocs.io/en/latest/api.html#module-depot.fields
    depot_file = Column(UploadedFileField, unique=False, nullable=True)
    properties = Column('properties', Text(), unique=False, nullable=False, default='')

    type = Column(Unicode(32), unique=False, nullable=False)
    status = Column(Unicode(32), unique=False, nullable=False, default=str(content_status_list.get_default_status().slug))
    created = Column(DateTime, unique=False, nullable=False, default=datetime.utcnow)
    updated = Column(DateTime, unique=False, nullable=False, default=datetime.utcnow)
    is_deleted = Column(Boolean, unique=False, nullable=False, default=False)
    is_archived = Column(Boolean, unique=False, nullable=False, default=False)
    is_temporary = Column(Boolean, unique=False, nullable=False, default=False)
    revision_type = Column(Unicode(32), unique=False, nullable=False, default='')

    workspace_id = Column(Integer, ForeignKey('workspaces.workspace_id'), unique=False, nullable=True)
    workspace = relationship('Workspace', remote_side=[Workspace.workspace_id])

    parent_id = Column(Integer, ForeignKey('content.id'), nullable=True, default=None)
    parent = relationship("Content", foreign_keys=[parent_id], back_populates="children_revisions")

    node = relationship("Content", foreign_keys=[content_id], back_populates="revisions")
    # TODO - G.M - 2018-06-177 - [author] Owner should be renamed "author"
    owner = relationship('User', remote_side=[User.user_id])

    """ List of column copied when make a new revision from another """
    _cloned_columns = (
        'content_id',
        'created',
        'description',
        'file_mimetype',
        'file_extension',
        'is_archived',
        'is_deleted',
        'label',
        'owner',
        'owner_id',
        'parent',
        'parent_id',
        'properties',
        'revision_type',
        'status',
        'type',
        'updated',
        'workspace',
        'workspace_id',
        'is_temporary',
    )

    # Read by must be used like this:
    # read_datetime = revision.ready_by[<User instance>]
    # if user did not read the content, then a key error is raised
    read_by = association_proxy(
        'revision_read_statuses',  # name of the attribute
        'view_datetime',  # attribute the value is taken from
        creator=lambda k, v: \
            RevisionReadStatus(user=k, view_datetime=v)
    )

    @hybrid_property
    def file_name(self) -> str:
        return '{0}{1}'.format(
            self.label,
            self.file_extension,
        )

    @file_name.setter
    def file_name(self, value: str) -> None:
        file_name, file_extension = os.path.splitext(value)
        self.label = file_name
        self.file_extension = file_extension

    @file_name.expression
    def file_name(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.label + ContentRevisionRO.file_extension


    @classmethod
    def new_from(cls, revision: 'ContentRevisionRO') -> 'ContentRevisionRO':
        """

        Return new instance of ContentRevisionRO where properties are copied from revision parameter.
        Look at ContentRevisionRO._cloned_columns to see what columns are copieds.

        :param revision: revision to copy
        :type revision: ContentRevisionRO
        :return: new revision from revision parameter
        :rtype: ContentRevisionRO
        """
        new_rev = cls()

        for column_name in cls._cloned_columns:
            column_value = getattr(revision, column_name)
            setattr(new_rev, column_name, column_value)

        new_rev.updated = datetime.utcnow()
        if revision.depot_file:
            new_rev.depot_file = FileIntent(
                revision.depot_file.file.read(),
                revision.file_name,
                revision.file_mimetype,
            )

        return new_rev

    @classmethod
    def copy(
            cls,
            revision: 'ContentRevisionRO',
            parent: 'Content'
    ) -> 'ContentRevisionRO':

        copy_rev = cls()
        import copy
        copy_columns = cls._cloned_columns
        for column_name in copy_columns:
            # INFO - G-M - 15-03-2018 - set correct parent
            if column_name == 'parent_id':
                column_value = copy.copy(parent.id)
            elif column_name == 'parent':
                column_value = copy.copy(parent)
            else:
                column_value = copy.copy(getattr(revision, column_name))
            setattr(copy_rev, column_name, column_value)

        # copy attached_file
        if revision.depot_file:
            copy_rev.depot_file = FileIntent(
                revision.depot_file.file.read(),
                revision.file_name,
                revision.file_mimetype,
            )
        return copy_rev

    def __setattr__(self, key: str, value: 'mixed'):
        """
        ContentRevisionUpdateError is raised if tried to update column and revision own identity
        :param key: attribute name
        :param value: attribute value
        :return:
        """
        if key in ('_sa_instance_state', ):  # Prevent infinite loop from SQLAlchemy code and altered set
            return super().__setattr__(key, value)

        # FIXME - G.M - 28-03-2018 - Cycling Import
        from tracim_backend.models.revision_protection import RevisionsIntegrity
        if inspect(self).has_identity \
                and key in self._cloned_columns \
                and not RevisionsIntegrity.is_updatable(self):
                raise ContentRevisionUpdateError(
                    "Can't modify revision. To work on new revision use tracim.model.new_revision " +
                    "context manager.")

        super().__setattr__(key, value)

    @property
    def is_active(self) -> bool:
        return not self.is_deleted and not self.is_archived

    @property
    def is_readonly(self) -> bool:
        return False

    def get_status(self) -> ContentStatus:
        try:
            return content_status_list.get_one_by_slug(self.status)
        except ContentStatusNotExist as exc:
            return content_status_list.get_default_status()

    def get_label(self) -> str:
        return self.label or self.file_name or ''

    def get_last_action(self) -> ActionDescription:
        return ActionDescription(self.revision_type)

    def has_new_information_for(self, user: User) -> bool:
        """
        :param user: the _session current user
        :return: bool, True if there is new information for given user else False
                       False if the user is None
        """
        if not user:
            return False

        if user not in self.read_by.keys():
            return True

        return False

# TODO - G.M - 2018-06-177 - [author] Owner should be renamed "author"
Index('idx__content_revisions__owner_id', ContentRevisionRO.owner_id)
Index('idx__content_revisions__parent_id', ContentRevisionRO.parent_id)


class Content(DeclarativeBase):
    """
    Content is used as a virtual representation of ContentRevisionRO.
    content.PROPERTY (except for content.id, content.revisions, content.children_revisions) will return
    value of most recent revision of content.

    # UPDATE A CONTENT

    To update an existing Content, you must use tracim.model.new_revision context manager:
    content = my_sontent_getter_method()
    with new_revision(content):
        content.description = 'foo bar baz'
    DBSession.flush()

    # QUERY CONTENTS

    To query contents you will need to join your content query with ContentRevisionRO. Join
    condition is available at tracim.lib.content.ContentApi#_get_revision_join:

    content = DBSession.query(Content).join(ContentRevisionRO, ContentApi._get_revision_join())
                  .filter(Content.label == 'foo')
                  .one()

    ContentApi provide also prepared Content at tracim.lib.content.ContentApi#get_canonical_query:

    content = ContentApi.get_canonical_query()
              .filter(Content.label == 'foo')
              .one()
    """

    __tablename__ = 'content'

    revision_to_serialize = -0  # This flag allow to serialize a given revision if required by the user

    id = Column(Integer, primary_key=True)
    # TODO - A.P - 2017-09-05 - revisions default sorting
    # The only sorting that makes sens is ordering by "updated" field. But:
    # - its content will soon replace the one of "created",
    # - this "updated" field will then be dropped.
    # So for now, we order by "revision_id" explicitly, but remember to switch
    # to "created" once "updated" removed.
    # https://github.com/tracim/tracim/issues/336
    revisions = relationship(
        "ContentRevisionRO",
        foreign_keys=[ContentRevisionRO.content_id],
        back_populates="node",
        order_by="ContentRevisionRO.revision_id"
    )
    children_revisions = relationship(
        "ContentRevisionRO",
        foreign_keys=[ContentRevisionRO.parent_id],
        back_populates="parent",
        order_by='ContentRevisionRO.revision_id',
    )

    @hybrid_property
    def content_id(self) -> int:
        return self.revision.content_id

    @content_id.setter
    def content_id(self, value: int) -> None:
        self.revision.content_id = value

    @content_id.expression
    def content_id(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.content_id

    @hybrid_property
    def revision_id(self) -> int:
        return self.revision.revision_id

    @revision_id.setter
    def revision_id(self, value: int):
        self.revision.revision_id = value

    @revision_id.expression
    def revision_id(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.revision_id

    # TODO - G.M - 2018-06-177 - [author] Owner should be renamed "author"
    # and should be author of first revision.
    @hybrid_property
    def owner_id(self) -> int:
        return self.revision.owner_id

    @owner_id.setter
    def owner_id(self, value: int) -> None:
        self.revision.owner_id = value

    @owner_id.expression
    def owner_id(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.owner_id

    @hybrid_property
    def label(self) -> str:
        return self.revision.label

    @label.setter
    def label(self, value: str) -> None:
        self.revision.label = value

    @label.expression
    def label(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.label

    @hybrid_property
    def description(self) -> str:
        return self.revision.description

    @description.setter
    def description(self, value: str) -> None:
        self.revision.description = value

    @description.expression
    def description(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.description

    @hybrid_property
    def file_name(self) -> str:
        return self.revision.file_name

    @file_name.setter
    def file_name(self, value: str) -> None:
        file_name, file_extension = os.path.splitext(value)
        self.label = file_name
        self.file_extension = file_extension

    @file_name.expression
    def file_name(cls) -> InstrumentedAttribute:
        return Content.label + Content.file_extension

    @hybrid_property
    def file_extension(self) -> str:
        return self.revision.file_extension

    @file_extension.setter
    def file_extension(self, value: str) -> None:
        self.revision.file_extension = value

    @file_extension.expression
    def file_extension(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.file_extension

    @hybrid_property
    def file_mimetype(self) -> str:
        return self.revision.file_mimetype

    @file_mimetype.setter
    def file_mimetype(self, value: str) -> None:
        self.revision.file_mimetype = value

    @file_mimetype.expression
    def file_mimetype(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.file_mimetype

    @hybrid_property
    def _properties(self) -> str:
        return self.revision.properties

    @_properties.setter
    def _properties(self, value: str) -> None:
        self.revision.properties = value

    @_properties.expression
    def _properties(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.properties

    @hybrid_property
    def type(self) -> str:
        return self.revision.type

    @type.setter
    def type(self, value: str) -> None:
        self.revision.type = value

    @type.expression
    def type(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.type

    @hybrid_property
    def status(self) -> str:
        return self.revision.status

    @status.setter
    def status(self, value: str) -> None:
        self.revision.status = value

    @status.expression
    def status(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.status

    @hybrid_property
    def created(self) -> datetime:
        return self.revision.created

    @created.setter
    def created(self, value: datetime) -> None:
        self.revision.created = value

    @created.expression
    def created(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.created

    @hybrid_property
    def updated(self) -> datetime:
        return self.revision.updated

    @updated.setter
    def updated(self, value: datetime) -> None:
        self.revision.updated = value

    @updated.expression
    def updated(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.updated

    @hybrid_property
    def is_deleted(self) -> bool:
        return self.revision.is_deleted

    @is_deleted.setter
    def is_deleted(self, value: bool) -> None:
        self.revision.is_deleted = value

    @is_deleted.expression
    def is_deleted(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.is_deleted

    @hybrid_property
    def is_archived(self) -> bool:
        return self.revision.is_archived

    @is_archived.setter
    def is_archived(self, value: bool) -> None:
        self.revision.is_archived = value

    @is_archived.expression
    def is_archived(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.is_archived

    @hybrid_property
    def is_temporary(self) -> bool:
        return self.revision.is_temporary

    @is_temporary.setter
    def is_temporary(self, value: bool) -> None:
        self.revision.is_temporary = value

    @is_temporary.expression
    def is_temporary(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.is_temporary

    @hybrid_property
    def revision_type(self) -> str:
        return self.revision.revision_type

    @revision_type.setter
    def revision_type(self, value: str) -> None:
        self.revision.revision_type = value

    @revision_type.expression
    def revision_type(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.revision_type

    @hybrid_property
    def workspace_id(self) -> int:
        return self.revision.workspace_id

    @workspace_id.setter
    def workspace_id(self, value: int) -> None:
        self.revision.workspace_id = value

    @workspace_id.expression
    def workspace_id(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.workspace_id

    @hybrid_property
    def workspace(self) -> Workspace:
        return self.revision.workspace

    @workspace.setter
    def workspace(self, value: Workspace) -> None:
        self.revision.workspace = value

    @workspace.expression
    def workspace(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.workspace

    @hybrid_property
    def parent_id(self) -> int:
        return self.revision.parent_id

    @parent_id.setter
    def parent_id(self, value: int) -> None:
        self.revision.parent_id = value

    @parent_id.expression
    def parent_id(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.parent_id

    @hybrid_property
    def parent(self) -> 'Content':
        return self.revision.parent

    @parent.setter
    def parent(self, value: 'Content') -> None:
        self.revision.parent = value

    @parent.expression
    def parent(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.parent

    @hybrid_property
    def node(self) -> 'Content':
        return self.revision.node

    @node.setter
    def node(self, value: 'Content') -> None:
        self.revision.node = value

    @node.expression
    def node(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.node

    # TODO - G.M - 2018-06-177 - [author] Owner should be renamed "author"
    # and should be author of first revision.
    @hybrid_property
    def owner(self) -> User:
        return self.revision.owner

    @owner.setter
    def owner(self, value: User) -> None:
        self.revision.owner = value

    @owner.expression
    def owner(cls) -> InstrumentedAttribute:
        return ContentRevisionRO.owner

    @hybrid_property
    def children(self) -> ['Content']:
        """
        :return: list of children Content
        :rtype Content
        """
        # Return a list of unique revisions parent content
        # TODO - G.M - 2018-10-24 - Set is just here to avoid distinct object,
        # check if possible to do this better, probably using database sorting
        # and sql distinct.
        revisions = set([revision.node for revision in self.children_revisions])
        revisions = sorted(revisions, key=lambda r: r.revision_id)
        return revisions

    @property
    def revision(self) -> ContentRevisionRO:
        return self.get_current_revision()

    @property
    def first_revision(self) -> ContentRevisionRO:
        return self.revisions[0]  # FIXME

    @property
    def last_revision(self) -> ContentRevisionRO:
        return self.revisions[-1]

    @property
    def is_readonly(self) -> bool:
        return self.revision.is_readonly

    @property
    def is_active(self) -> bool:
        return self.revision.is_active

    @property
    def depot_file(self) -> UploadedFile:
        return self.revision.depot_file

    @depot_file.setter
    def depot_file(self, value):
        self.revision.depot_file = value

    def get_current_revision(self) -> ContentRevisionRO:
        if not self.revisions:
            return self.new_revision()

        # If last revisions revision don't have revision_id, return it we just add it.
        if self.revisions[-1].revision_id is None:
            return self.revisions[-1]

        # Revisions should be ordred by revision_id but we ensure that here
        revisions = sorted(self.revisions, key=lambda revision: revision.revision_id)
        return revisions[-1]

    def new_revision(self) -> ContentRevisionRO:
        """
        Return and assign to this content a new revision.
        If it's a new content, revision is totally new.
        If this content already own revision, revision is build from last revision.
        :return:
        """
        if not self.revisions:
            self.revisions.append(ContentRevisionRO())
            return self.revisions[0]

        new_rev = ContentRevisionRO.new_from(self.get_current_revision())
        self.revisions.append(new_rev)
        return new_rev

    def get_valid_children(self, content_types: list=None) -> ['Content']:
        for child in self.children:
            if not child.is_deleted and not child.is_archived:
                if not content_types or child.type in content_types:
                    yield child.node

    @hybrid_property
    def properties(self) -> dict:
        """ return a structure decoded from json content of _properties """

        if not self._properties:
            properties = {}
        else:
            properties = json.loads(self._properties)
        if content_type_list.get_one_by_slug(self.type) != content_type_list.Event:
            if not 'allowed_content' in properties:
                properties['allowed_content'] = content_type_list.default_allowed_content_properties(self.type)  # nopep8
        return properties

    @properties.setter
    def properties(self, properties_struct: dict) -> None:
        """ encode a given structure into json and store it in _properties attribute"""
        self._properties = json.dumps(properties_struct)
        ContentChecker.check_properties(self)

    def created_as_delta(self, delta_from_datetime:datetime=None):
        if not delta_from_datetime:
            delta_from_datetime = datetime.utcnow()

        return format_timedelta(delta_from_datetime - self.created,
                                locale=get_locale())

    def datetime_as_delta(self, datetime_object,
                          delta_from_datetime:datetime=None):
        if not delta_from_datetime:
            delta_from_datetime = datetime.utcnow()
        return format_timedelta(delta_from_datetime - datetime_object,
                                locale=get_locale())

    def get_child_nb(self, content_type: str, content_status = ''):
        child_nb = 0
        for child in self.get_valid_children():
            if child.type == content_type or content_type.slug == content_type_list.Any_SLUG:
                if not content_status:
                    child_nb = child_nb+1
                elif content_status==child.status:
                    child_nb = child_nb+1
        return child_nb

    def get_label(self):
        return self.label or self.file_name or ''

    def get_status(self) -> ContentStatus:
        return self.revision.get_status()

    def get_last_action(self) -> ActionDescription:
        return ActionDescription(self.revision_type)

    def get_simple_last_activity_date(self) -> datetime_root.datetime:
        """
        Get last activity_date, comments_included. Do not search recursively
        in revision or children.
        :return:
        """
        last_revision_date = self.updated
        for comment in self.get_comments():
            if comment.updated > last_revision_date:
                last_revision_date = comment.updated
        return last_revision_date

    def get_last_activity_date(self) -> datetime_root.datetime:
        """
        Get last activity date with complete recursive search
        :return:
        """
        last_revision_date = self.updated
        for revision in self.revisions:
            if revision.updated > last_revision_date:
                last_revision_date = revision.updated

        for child in self.children:
            if child.updated > last_revision_date:
                last_revision_date = child.updated
        return last_revision_date

    def has_new_information_for(self, user: User) -> bool:
        """
        :param user: the _session current user
        :return: bool, True if there is new information for given user else False
                       False if the user is None
        """
        revision = self.get_current_revision()

        if not user:
            return False

        if user not in revision.read_by.keys():
            # The user did not read this item, so yes!
            return True

        for child in self.get_valid_children():
            if child.has_new_information_for(user):
                return True

        return False

    def get_comments(self):
        children = []
        for child in self.children:
            if content_type_list.Comment.slug == child.type and not child.is_deleted and not child.is_archived:
                children.append(child.node)
        return children

    def get_last_comment_from(self, user: User) -> 'Content':
        # TODO - Make this more efficient
        last_comment_updated = None
        last_comment = None
        for comment in self.get_comments():
            if user.user_id == comment.owner.user_id:
                if not last_comment or last_comment_updated<comment.updated:
                    # take only the latest comment !
                    last_comment = comment
                    last_comment_updated = comment.updated

        return last_comment

    def get_previous_revision(self) -> 'ContentRevisionRO':
        rev_ids = [revision.revision_id for revision in self.revisions]
        rev_ids.sort()

        if len(rev_ids)>=2:
            revision_rev_id = rev_ids[-2]

            for revision in self.revisions:
                if revision.revision_id == revision_rev_id:
                    return revision

        return None

    def description_as_raw_text(self):
        # 'html.parser' fixes a hanging bug
        # see http://stackoverflow.com/questions/12618567/problems-running-beautifulsoup4-within-apache-mod-python-django
        return BeautifulSoup(self.description, 'html.parser').text

    def get_allowed_content_types(self):
        types = []
        try:
            allowed_types = self.properties['allowed_content']
            for type_label, is_allowed in allowed_types.items():
                if is_allowed:
                   types.append(
                        content_type_list.get_one_by_slug(type_label)
                   )
        # TODO BS 2018-08-13: This try/except is not correct: except exception
        # if we know what to except.
        except Exception as e:
            print(e.__str__())
            print('----- /*\ *****')
            raise ValueError('Not allowed content property')

        return types

    def get_history(self, drop_empty_revision=False) -> '[VirtualEvent]':
        events = []
        for comment in self.get_comments():
            events.append(VirtualEvent.create_from_content(comment))

        revisions = sorted(self.revisions, key=lambda rev: rev.revision_id)
        for revision in revisions:
            # INFO - G.M - 09-03-2018 - Do not show file revision with empty
            # file to have a more clear view of revision.
            # Some webdav client create empty file before uploading, we must
            # have possibility to not show the related revision
            if drop_empty_revision:
                if revision.depot_file and revision.depot_file.file.content_length == 0:  # nopep8
                    # INFO - G.M - 12-03-2018 -Always show the last and
                    # first revision.
                    if revision != revisions[-1] and revision != revisions[0]:
                        continue

            events.append(VirtualEvent.create_from_content_revision(revision))

        sorted_events = sorted(events,
                               key=lambda event: event.created, reverse=True)
        return sorted_events

    @classmethod
    def format_path(cls, url_template: str, content: 'Content') -> str:
        wid = content.workspace.workspace_id
        fid = content.parent_id  # May be None if no parent
        ctype = content.type
        cid = content.content_id
        return url_template.format(wid=wid, fid=fid, ctype=ctype, cid=cid)

    def copy(self, parent):
        cpy_content = Content()
        for rev in self.revisions:
            cpy_rev = ContentRevisionRO.copy(rev, parent)
            cpy_content.revisions.append(cpy_rev)
        return cpy_content


class RevisionReadStatus(DeclarativeBase):

    __tablename__ = 'revision_read_status'

    revision_id = Column(Integer, ForeignKey('content_revisions.revision_id', ondelete='CASCADE', onupdate='CASCADE'), primary_key=True)
    user_id = Column(Integer, ForeignKey('users.user_id', ondelete='CASCADE', onupdate='CASCADE'), primary_key=True)
    #  Default value datetime.utcnow, see: http://stackoverflow.com/a/13370382/801924 (or http://pastebin.com/VLyWktUn)
    view_datetime = Column(DateTime, unique=False, nullable=False, default=datetime.utcnow)

    content_revision = relationship(
        'ContentRevisionRO',
        backref=backref(
            'revision_read_statuses',
            collection_class=attribute_mapped_collection('user'),
            cascade='all, delete-orphan'
        ))

    user = relationship('User', backref=backref(
        'revision_readers',
        collection_class=attribute_mapped_collection('view_datetime'),
        cascade='all, delete-orphan'
    ))


class NodeTreeItem(object):
    """
        This class implements a model that allow to simply represents
        the left-panel menu items. This model is used by dbapi but
        is not directly related to sqlalchemy and database
    """
    def __init__(
        self,
        node: Content,
        children: typing.List['NodeTreeItem'],
        is_selected: bool = False,
    ):
        self.node = node
        self.children = children
        self.is_selected = is_selected


class VirtualEvent(object):
    @classmethod
    def create_from(cls, object):
        if Content == object.__class__:
            return cls.create_from_content(object)
        elif ContentRevisionRO == object.__class__:
            return cls.create_from_content_revision(object)

    @classmethod
    def create_from_content(cls, content: Content):

        label = content.get_label()
        if content.type == content_type_list.Comment.slug:
            # TODO - G.M  - 10-04-2018 - [Cleanup] Remove label param
            # from this object ?
            # TODO - G.M - 2018-08-20 - [I18n] fix trad of this
            label = '<strong>{}</strong> wrote:'.format(content.owner.get_display_name())

        return VirtualEvent(id=content.content_id,
                            created=content.created,
                            owner=content.owner,
                            type=ActionDescription(content.revision_type),
                            label=label,
                            content=content.description,
                            ref_object=content)

    @classmethod
    def create_from_content_revision(cls, revision: ContentRevisionRO):
        action_description = ActionDescription(revision.revision_type)

        return VirtualEvent(id=revision.revision_id,
                            created=revision.updated,
                            owner=revision.owner,
                            type=action_description,
                            label=action_description.label,
                            content='',
                            ref_object=revision)

    def __init__(self, id, created, owner, type, label, content, ref_object):
        self.id = id
        self.created = created
        self.owner = owner
        self.type = type
        self.label = label
        self.content = content
        self.ref_object = ref_object

        assert hasattr(type, 'id')
        # TODO - G.M - 10-04-2018 - [Cleanup] Drop this
        # assert hasattr(type, 'css')
        # assert hasattr(type, 'fa_icon')
        # assert hasattr(type, 'label')

    def created_as_delta(self, delta_from_datetime:datetime=None):
        if not delta_from_datetime:
            delta_from_datetime = datetime.utcnow()
        return format_timedelta(delta_from_datetime - self.created,
                                locale=get_locale())

    def create_readable_date(self, delta_from_datetime:datetime=None):

This code seems to be duplicated in your project.

        aff = ''

        if not delta_from_datetime:
            delta_from_datetime = datetime.utcnow()

        delta = delta_from_datetime - self.created

        if delta.days > 0:
            if delta.days >= 365:
                aff = '%d year%s ago' % (delta.days/365, 's' if delta.days/365>=2 else '')
            elif delta.days >= 30:
                aff = '%d month%s ago' % (delta.days/30, 's' if delta.days/30>=2 else '')
            else:
                aff = '%d day%s ago' % (delta.days, 's' if delta.days>=2 else '')
        else:
            if delta.seconds < 60:
                aff = '%d second%s ago' % (delta.seconds, 's' if delta.seconds>1 else '')
            elif delta.seconds/60 < 60:
                aff = '%d minute%s ago' % (delta.seconds/60, 's' if delta.seconds/60>=2 else '')
            else:
                aff = '%d hour%s ago' % (delta.seconds/3600, 's' if delta.seconds/3600>=2 else '')

        return aff