from uuid import uuid4

from sqlalchemy import BigInteger, Column, Enum as DBEnum, ForeignKey, Unicode
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import backref, relationship
from sqlalchemy.util import OrderedSet
from teal.db import CASCADE_OWN

from ereuse_devicehub.db import db
from ereuse_devicehub.resources.device.models import Device
from ereuse_devicehub.resources.enums import ImageMimeTypes, Orientation
from ereuse_devicehub.resources.models import STR_BIG_SIZE, Thing


class ImageList(Thing):
    id = db.Column(UUID(as_uuid=True), primary_key=True, default=uuid4)
    device_id = Column(BigInteger, ForeignKey(Device.id), nullable=False)
    device = relationship(Device,
                          primaryjoin=Device.id == device_id,
                          backref=backref('images',
                                          lazy=True,
                                          cascade=CASCADE_OWN,
                                          order_by=lambda: ImageList.created,
                                          collection_class=OrderedSet))


class Image(Thing):
    id = db.Column(UUID(as_uuid=True), primary_key=True, default=uuid4)
    name = Column(Unicode(STR_BIG_SIZE), default='', nullable=False)
    content = db.Column(db.LargeBinary, nullable=False)
    file_format = db.Column(DBEnum(ImageMimeTypes), nullable=False)
    orientation = db.Column(DBEnum(Orientation), nullable=False)
    image_list_id = Column(UUID(as_uuid=True), ForeignKey(ImageList.id), nullable=False)
    image_list = relationship(ImageList,
                              primaryjoin=ImageList.id == image_list_id,
                              backref=backref('images',
                                              cascade=CASCADE_OWN,
                                              order_by=lambda: Image.created,
                                              collection_class=OrderedSet))

    # todo make an image Field that converts to/from image object
    # todo which metadata we get from Photobox?