import hashlib
import datetime

import sqlalchemy as sa
from sqlalchemy import Column, Table, ForeignKey, types, UniqueConstraint
from sqlalchemy.orm import relation, backref

from imagery.model.meta import Session, DeclarativeBase, metadata
from imagery.model import Album


""" * * * * * * * * * * * * * """
""" * * Association Tables  * """

class AlbumOwner(DeclarativeBase):
    __tablename__ = 'albumOwner'

    album_id = Column(types.Integer, ForeignKey('album.id'), nullable=False, primary_key=True, unique=True)
    user_id = Column(types.Integer, ForeignKey('user.id'), nullable=False)

class PhotoOwner(DeclarativeBase):
    __tablename__ = 'photoOwner'

    photo_id = Column(types.Integer, ForeignKey('photo.id'), nullable=False, primary_key=True, unique=True)
    user_id = Column(types.Integer, ForeignKey('user.id'), nullable=False)


class GroupPermission(DeclarativeBase):
    __tablename__ = 'groupPermission'

    group_id = Column(types.Integer, ForeignKey('group.id'), nullable=False, primary_key=True)
    permission_id = Column(types.Integer, ForeignKey('permission.id'), nullable=False, primary_key=True)

class UserGroup(DeclarativeBase):
    __tablename__ = 'userGroup'

    group_id = Column(types.Integer, ForeignKey('group.id'), nullable=False, primary_key=True)
    user_id = Column(types.Integer, ForeignKey('user.id'), nullable=False, primary_key=True)


""" * * * * * * * * * * * * * """
""" * * * * *  User * * * * * """

class User(DeclarativeBase):
    __tablename__ = 'user'

    id = Column(types.Integer, primary_key=True)
    username = Column(types.String(16), nullable=False, unique=True)
    _password = Column('password', types.String(255), nullable=False)
    name = Column(types.String(255))
    email = Column(types.String(128))
    create_date = Column(types.DateTime, nullable=True)

    ownedAlbums = relation('Album', secondary=AlbumOwner.__table__, backref=backref('owner', uselist=False), single_parent=True)
    ownedPhotos = relation('Photo', secondary=PhotoOwner.__table__, backref=backref('owner', uselist=False), single_parent=True)

    def __init__(self, username, passwd, name = None, email = None):
        self.username = username
        self.password = passwd
        self.name = name
        self.email = email
        self.create_date = datetime.datetime.now()

    def validate_password(self, password):
        p = hashlib.md5(password).hexdigest()
        return (self.password == p)

    def __get_password__(self):
        return self._password

    def __set_password__(self, password):
        p = hashlib.md5(password).hexdigest()
        self._password = p

    password = property(__get_password__, __set_password__)


""" * * * * * * * * * * * * * """
""" * * * * Permission  * * * """

class Permission(DeclarativeBase):
    __tablename__ = 'permission'

    id = Column(types.Integer, primary_key=True)
    name = Column(types.String(16), nullable=False)
    title = Column(types.String(64))
    context = Column(types.String(64), nullable=False)
    __mapper_args__ = {'polymorphic_on' : context}

    groups = relation('Group', secondary=GroupPermission.__table__)

    def __init__(self, name, context, title=None, initial_groups=[]):
        self.name = name
        self.title = title
        self.context = context
        self.groups = initial_groups


class GlobalPermission(Permission):
    __mapper_args__ = {'polymorphic_identity' : 'global'}

    def __init__(self, name, title=None, initial_groups=[]):
        self.name = name
        self.title = title
        self.groups = initial_groups

class AlbumPermission(Permission):
    __mapper_args__ = {'polymorphic_identity' : 'album'}

    def __init__(self, name, title=None, initial_groups=[]):
        self.name = name
        self.title = title
        self.groups = initial_groups



""" * * * * * * * * * * * * * """
""" * * * * *  Group  * * * * """

class Group(DeclarativeBase):
    __tablename__ = 'group'

    id = Column(types.Integer, primary_key=True)
    name = Column(types.String(16), nullable=False, unique=True)
    create_date = Column(types.DateTime, nullable=True)

    users = relation('User', secondary=UserGroup.__table__, backref=backref('groups'))
    permissions = relation('Permission', secondary=GroupPermission.__table__)

    def __init__(self, name, initial_members=[]):
        self.name = name
        self.create_date = datetime.datetime.now()
        self.users = initial_members