"""uvicorn entry point: `uvicorn intern_decision_serve.main:app_from_env --factory --workers 1`."""
from __future__ import annotations

import os

from fastapi import FastAPI

from .app import create_app, inference_thread
from .config import Settings


def app_from_env() -> FastAPI:
    settings = Settings.from_env(os.environ)
    # INV-5: never download at runtime, inside the image or out of it. Set before torch /
    # transformers / huggingface_hub are imported, since they read it at import time.
    os.environ["HF_HUB_OFFLINE"] = "1"
    os.environ["TRANSFORMERS_OFFLINE"] = "1"
    from .engine import TorchEngine   # torch loads only inside load(), never in the unit tests

    # INV-2: load, warm-up and every later call run on this one thread (per-thread CUDA state).
    executor = inference_thread()
    engine = executor.submit(TorchEngine.load, settings).result()
    return create_app(settings, engine, executor)