"""PostgresConnectionManager dependency functions are defined here."""

from fastapi import FastAPI, Request

from {{project_slug}}.db.connection.manager import PostgresConnectionManager


def init_dispencer(app: FastAPI, connection_manager: PostgresConnectionManager) -> None:
    """Initialize PostgresConnectionManager dispencer at app's state."""
    if hasattr(app.state, "postgres_connection_manager_dep"):
        if not isinstance(app.state.postgres_connection_manager_dep, PostgresConnectionManager):
            raise ValueError(
                "postgres_connection_manager_dep attribute of app's state is already set"
                f"with other value ({app.state.postgres_connection_manager_dep})"
            )
        return

    app.state.postgres_connection_manager_dep = connection_manager


def from_app(app: FastAPI) -> PostgresConnectionManager:
    """Get a connection_manager from app state."""
    if not hasattr(app.state, "postgres_connection_manager_dep"):
        raise ValueError("PostgresConnectionManager dispencer was not initialized at app preparation")
    return app.state.postgres_connection_manager_dep


async def from_request(request: Request) -> PostgresConnectionManager:
    """Get a PostgresConnectionManager from request or app state."""
    if hasattr(request.state, "postgres_connection_manager_dep"):
        connection_manager = request.state.postgres_connection_manager_dep
        if isinstance(connection_manager, PostgresConnectionManager):
            return connection_manager
    return from_app(request.app)