import logging
from contextlib import asynccontextmanager

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

from app.api.router import api_router
from app.config import settings

logger = logging.getLogger("olivas")


@asynccontextmanager
async def lifespan(app: FastAPI):
    # Startup: load ML models
    logger.info(f"Starting OliVAS backend (device={settings.device})")
    from app.services.saliency.model_manager import model_manager

    try:
        model_manager.load_models(device=settings.device)
        logger.info(f"Models loaded: {list(model_manager.models.keys())}")
    except Exception as e:
        logger.warning(f"Failed to load ML models: {e}. Analysis will fail until models load.")

    yield

    # Shutdown
    model_manager.cleanup()
    logger.info("OliVAS backend shut down")


app = FastAPI(
    title="OliVAS",
    description="Open-Source Visual Attention Software by OLIVER",
    version="0.1.0",
    lifespan=lifespan,
)

app.add_middleware(
    CORSMiddleware,
    allow_origins=settings.cors_origins_list,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

app.include_router(api_router)