"""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"):
        if not isinstance(app.state.postgres_connection_manager, PostgresConnectionManager):
            raise ValueError(
                "postgres_connection_manager attribute of app's state is already set"
                f"with other value ({app.state.postgres_connection_manager})"
            )
        return

    app.state.postgres_connection_manager = connection_manager


def obtain(request: Request) -> PostgresConnectionManager:
    """Get a PostgresConnectionManager from request's app state."""
    if not hasattr(request.app.state, "postgres_connection_manager"):
        raise ValueError("PostgresConnectionManager dispencer was not initialized at app preparation")
    return request.app.state.postgres_connection_manager