from __future__ import annotations

from collections.abc import Callable
from contextlib import asynccontextmanager

from fastapi import FastAPI

from cloud.auth import create_auth_provider
from cloud.control_config import (
    CloudControlConfig,
    load_control_config,
    validate_control_config,
)
from cloud.database import CloudDatabase


DatabaseFactory = Callable[[CloudControlConfig], CloudDatabase]


def create_app(
    *,
    config: CloudControlConfig | None = None,
    database_factory: DatabaseFactory | None = None,
) -> FastAPI:
    """Create the independently deployable cloud API application."""
    control_config = config or load_control_config()
    validate_control_config(control_config)
    build_database = database_factory or _default_database_factory
    auth_provider = create_auth_provider(
        control_config.credentials,
        allow_insecure_anonymous=control_config.allow_insecure_anonymous,
    )

    @asynccontextmanager
    async def lifespan(app: FastAPI):
        database = build_database(control_config)
        app.state.cloud_config = control_config
        app.state.database = database
        app.state.auth_provider = auth_provider
        try:
            yield
        finally:
            database.close()

    return FastAPI(title="Device Cloud API", lifespan=lifespan)


def _default_database_factory(config: CloudControlConfig) -> CloudDatabase:
    return CloudDatabase(
        config.database_url,
        create_schema=config.environment != "production",
    )