tracim_v2/tracim/models/data.py

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

import datetime as datetime_root
import json
import os
from datetime import datetime
from typing import TYPE_CHECKING

from babel.dates import format_timedelta
from bs4 import BeautifulSoup
from sqlalchemy import Column, inspect, Index
from sqlalchemy import ForeignKey
from sqlalchemy import Sequence
from sqlalchemy.ext.associationproxy import association_proxy
from sqlalchemy.ext.hybrid import hybrid_property
from sqlalchemy.orm import backref
from sqlalchemy.orm import deferred
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 LargeBinary
from sqlalchemy.types import Text
from sqlalchemy.types import Unicode
from depot.fields.sqlalchemy import UploadedFileField
from depot.fields.upload import UploadedFile
from depot.io.utils import FileIntent

from tracim.translation import fake_translator as l_
from tracim.exceptions import ContentRevisionUpdateError
from tracim.models.meta import DeclarativeBase
from tracim.models.auth import User

DEFAULT_PROPERTIES = dict(
    allowed_content=dict(
        folder=True,
        file=True,
        page=True,
        thread=True,
    ),
)


class BreadcrumbItem(object):

    def __init__(self, icon_string: str, label: str, url: str, is_active: bool = False):
        """
            A BreadcrumbItem contains minimal information required to build a breadcrumb
            icon_string: this is the Tango related id, eg 'places/remote-folder'
        """
        self.icon = icon_string
        self.label = label
        self.url = url
        self.is_active =is_active

class Workspace(DeclarativeBase):

    __tablename__ = 'workspaces'

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

    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] Check about calendar code
    # @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 [ContentType('folder')]

    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 = 0
    READER = 1
    CONTRIBUTOR = 2
    CONTENT_MANAGER = 4
    WORKSPACE_MANAGER = 8

    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')

    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 icon(self):
        return UserRoleInWorkspace.ICON[self.role]

    @property
    def style(self):
        return UserRoleInWorkspace.STYLE[self.role]

    def role_as_label(self):
        return UserRoleInWorkspace.LABEL[self.role]

    @classmethod
    def get_all_role_values(self):
        return [
            UserRoleInWorkspace.READER,
            UserRoleInWorkspace.CONTRIBUTOR,
            UserRoleInWorkspace.CONTENT_MANAGER,
            UserRoleInWorkspace.WORKSPACE_MANAGER
        ]

class RoleType(object):
    def __init__(self, role_id):
        self.role_type_id = role_id
        self.icon = UserRoleInWorkspace.ICON[role_id]
        self.role_label = UserRoleInWorkspace.LABEL[role_id]
        self.css_style = UserRoleInWorkspace.STYLE[role_id]


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'

    _ICONS = {
        'archiving': 'fa fa-archive',
        'content-comment': 'fa-comment-o',
        'creation': 'fa-magic',
        'deletion': 'fa-trash',
        'edition': 'fa-edit',
        'revision': 'fa-history',
        'status-update': 'fa-random',
        'unarchiving': 'fa-file-archive-o',
        'undeletion': 'fa-trash-o',
        'move': 'fa-arrows',
        'copy': 'fa-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
        self.label = ActionDescription._LABELS[id]
        self.icon = ActionDescription._ICONS[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,
                ]


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'

    _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, type=''):
        self.id = id
        self.icon = ContentStatus._ICONS[id]
        self.css = ContentStatus._CSS[id]

        if type==ContentType.Thread:
            self.label = ContentStatus._LABELS_THREAD[id]
        elif type==ContentType.File:
            self.label = ContentStatus._LABELS_FILE[id]
        else:
            self.label = ContentStatus._LABELS[id]


    @classmethod
    def all(cls, type='') -> ['ContentStatus']:
        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

    @classmethod
    def allowed_values(cls):
        return ContentStatus._LABELS.keys()

class ContentType(object):
    Any = 'any'

    Folder  = 'folder'
    File    = 'file'
    Comment = 'comment'
    Thread = 'thread'
    Page = 'page'
    Event = 'event'

    # Fake types, used for breadcrumb only
    FAKE_Dashboard = 'dashboard'
    FAKE_Workspace = 'workspace'

    _STRING_LIST_SEPARATOR = ','

    _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,
    }

    _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]

    @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==ContentType.Folder:
            return '/workspaces/{}/folders/{}'.format(content.workspace_id, content.content_id)
        elif content.type==ContentType.File:
            return '/workspaces/{}/folders/{}/files/{}'.format(content.workspace_id, content.parent_id, content.content_id)
        elif content.type==ContentType.Thread:
            return '/workspaces/{}/folders/{}/threads/{}'.format(content.workspace_id, content.parent_id, content.content_id)
        elif content.type==ContentType.Page:
            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
        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,
                    icon=self.icon,
                    color=self.color,
                    label=self.label,
                    priority=self.priority)


class ContentChecker(object):

    @classmethod
    def check_properties(cls, item):
        if item.type==ContentType.Folder:
            properties = item.properties
            if 'allowed_content' not in properties.keys():
                return False
            if 'folders' not in properties['allowed_content']:
                return False
            if 'files' not in properties['allowed_content']:
                return False
            if 'pages' not in properties['allowed_content']:
                return False
            if 'threads' not in properties['allowed_content']:
                return False
            return True

        if item.type == ContentType.Event:
            properties = item.properties
            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

        # TODO - G.M - 15-03-2018 - Choose only correct Content-type for origin
        # Only content who can be copied need this
        if item.type == ContentType.Any:
            properties = item.properties
            if 'origin' in properties.keys():
                return True
        raise NotImplementedError

    @classmethod
    def reset_properties(cls, item):
        if item.type==ContentType.Folder:
            item.properties = DEFAULT_PROPERTIES
            return

        raise NotImplementedError


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)
    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=ContentStatus.OPEN)
    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")
    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)
    )

    @property
    def file_name(self):
        return '{0}{1}'.format(
            self.label,
            self.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.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)

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

    def get_label_as_file(self):
        file_extension = self.file_extension or ''

        if self.type == ContentType.Thread:
            file_extension = '.html'
        elif self.type == ContentType.Page:
            file_extension = '.html'

        return '{0}{1}'.format(
            self.label,
            file_extension,
        )


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")

    @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

    @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 '{0}{1}'.format(
            self.revision.label,
            self.revision.file_extension,
        )

    @file_name.setter
    def file_name(self, value: str) -> None:
        file_name, file_extension = os.path.splitext(value)
        if not self.revision.label:
            self.revision.label = file_name
        self.revision.file_extension = file_extension

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

    @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
        return list(set([revision.node for revision in self.children_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_editable(self) -> bool:
        return not self.is_archived and not self.is_deleted

    @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:
            return DEFAULT_PROPERTIES
        return json.loads(self._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=tg.i18n.get_lang()[0])

    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=tg.i18n.get_lang()[0])

    def get_child_nb(self, content_type: ContentType, content_status = ''):
        child_nb = 0
        for child in self.get_valid_children():
            if child.type == content_type or content_type == ContentType.Any:
                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_label_as_file(self) -> str:
        """
        :return: Return content label in file representation context
        """
        return self.revision.get_label_as_file()

    def get_status(self) -> ContentStatus:
        return ContentStatus(self.status, self.type.__str__())

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

    def get_last_activity_date(self) -> datetime_root.datetime:
        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 ContentType.Comment==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(ContentType(type_label))
        except Exception as e:
            print(e.__str__())
            print('----- /*\ *****')
            raise ValueError('Not allowed content property')

        return ContentType.sorted(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: list('NodeTreeItem'), is_selected = 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):
        content_type = ContentType(content.type)

        label = content.get_label()
        if content.type==ContentType.Comment:
            # TODO :  28-03-2018 [i18n] Internationalize this ?
            label = ('<strong>{}</strong> wrote:').format(content.owner.get_display_name())

        return VirtualEvent(id=content.content_id,
                            created=content.created,
                            owner=content.owner,
                            type=content_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')
        assert hasattr(type, 'css')
        assert hasattr(type, '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=tg.i18n.get_lang()[0])

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