import warnings
from sqlalchemy import String, Column, ForeignKey, UniqueConstraint, TypeDecorator
from sqlalchemy.orm import relationship
from orm.base import Base, REGISTRY, engine, local_session
from orm.community import Community


class ClassType(TypeDecorator):
	impl = String

	@property
	def python_type(self):
		return NotImplemented

	def process_literal_param(self, value, dialect):
		return NotImplemented

	def process_bind_param(self, value, dialect):
		return value.__name__ if isinstance(value, type) else str(value)

	def process_result_value(self, value, dialect):
		class_ = REGISTRY.get(value)
		if class_ is None:
			warnings.warn(f"Can't find class <{value}>,find it yourself!", stacklevel=2)
		return class_

class Role(Base):
	__tablename__ = 'role'

	name: str = Column(String, nullable=False, comment="Role Name")
	desc: str = Column(String, nullable=True, comment="Role Description")
	community: int = Column(ForeignKey("community.id", ondelete="CASCADE"), nullable=False, comment="Community")
	permissions = relationship(lambda: Permission)

	@staticmethod
	def init_table():
		with local_session() as session:
			default = session.query(Role).filter(Role.name == "author").first()
		if default:
			Role.default_role = default
			return

		default = Role.create(
			name = "author",
			desc = "Role for author",
			community = Community.default_community.id
		)

		Role.default_role = default

class Operation(Base):
	__tablename__ = 'operation'
	name: str = Column(String, nullable=False, unique=True, comment="Operation Name")

	@staticmethod
	def init_table():
		with local_session() as session:
			edit_op = session.query(Operation).filter(Operation.name == "edit").first()
		if not edit_op:
			edit_op = Operation.create(name = "edit")
		Operation.edit_id = edit_op.id


class Resource(Base):
	__tablename__ = "resource"
	resource_class: str = Column(String, nullable=False, unique=True, comment="Resource class")
	name: str = Column(String, nullable=False, unique=True, comment="Resource name")

	@staticmethod
	def init_table():
		with local_session() as session:
			shout_res = session.query(Resource).filter(Resource.name == "shout").first()
		if not shout_res:
			shout_res = Resource.create(name = "shout", resource_class = "shout")
		Resource.shout_id = shout_res.id


class Permission(Base):
	__tablename__ = "permission"
	__table_args__ = (UniqueConstraint("role_id", "operation_id", "resource_id"), {"extend_existing": True})

	role_id: int = Column(ForeignKey("role.id", ondelete="CASCADE"), nullable=False, comment="Role")
	operation_id: int = Column(ForeignKey("operation.id", ondelete="CASCADE"), nullable=False, comment="Operation")
	resource_id: int = Column(ForeignKey("resource.id", ondelete="CASCADE"), nullable=False, comment="Resource")


if __name__ == '__main__':
	Base.metadata.create_all(engine)
	ops = [
		Permission(role_id=1, operation_id=1, resource_id=1),
		Permission(role_id=1, operation_id=2, resource_id=1),
		Permission(role_id=1, operation_id=3, resource_id=1),
		Permission(role_id=1, operation_id=4, resource_id=1),
		Permission(role_id=2, operation_id=4, resource_id=1)
	]
	global_session.add_all(ops)
	global_session.commit()