"""Shared datasources — initialised once via FastAPI lifespan."""

import logging
from contextlib import asynccontextmanager
from typing import Any, AsyncIterator

from fastapi import FastAPI
from owsclient import OwsClient
from owscontext import get_correlation_id, get_request_context
from python_pdp_sdk import MigrationAuthorizationBackend, PdpAuthorizationBackend
from python_pdp_sdk.backends.authorization_backend import AuthorizationBackend
from python_pdp_sdk.connectors.ows_pdp.ows_pdp import OwsPdpClient

import config
from context import request_tags

logger = logging.getLogger(__name__)

AUTHORIZATION_BACKEND_KEY = "AUTHORIZATION_BACKEND"
OWS_CLIENT_KEY = "OWS_CLIENT"

DATA_SOURCES: dict[str, Any] = {}


@asynccontextmanager
async def lifespan(app: FastAPI) -> AsyncIterator[dict[str, Any]]:
    ows_client = setup_ows_client()
    logger.info("[lifespan] Initialized ows client")
    DATA_SOURCES[OWS_CLIENT_KEY] = ows_client

    authorization_backend = setup_authorization_backend(ows_client)
    logger.info("[lifespan] Initialized authorization backend")
    DATA_SOURCES[AUTHORIZATION_BACKEND_KEY] = authorization_backend

    try:
        yield DATA_SOURCES
    finally:
        DATA_SOURCES.clear()


def setup_ows_client() -> OwsClient:
    """Create and return a configured OwsClient instance."""
    return OwsClient(
        environment=config.ENVIRONMENT,
        service_name=config.SERVICE_NAME,
        correlation_id_getter=get_correlation_id,
        request_context_getter=get_request_context,
    )


def setup_authorization_backend(ows_client: OwsClient) -> AuthorizationBackend:
    """Create and return a MigrationAuthorizationBackend wrapping PdpAuthorizationBackend."""
    pdp_backend = PdpAuthorizationBackend(OwsPdpClient(ows_client))
    return MigrationAuthorizationBackend(
        inner_backend=pdp_backend,
        service_name=config.SERVICE_NAME,
        environment=config.DD_ENV,
        dd_api_key=config.DD_API_KEY,
        extra_tags_getter=request_tags,
    )


def get_authorization_backend() -> AuthorizationBackend:
    return DATA_SOURCES[AUTHORIZATION_BACKEND_KEY]