from contextlib import asynccontextmanager

from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles
from starlette.middleware.gzip import GZipMiddleware

from logsetup import setup_logging

setup_logging()

from config import FRONTEND_DIST, STORAGE_DIR
from database import init_db, close_db
from guide import reconcile_guides
from routes import router


@asynccontextmanager
async def lifespan(app: FastAPI):
    (STORAGE_DIR / "topics").mkdir(parents=True, exist_ok=True)
    await init_db()
    await reconcile_guides()
    yield
    await close_db()


class CachedStatic(StaticFiles):
    """StaticFiles with Cache-Control: hashed assets forever (immutable),
    index.html never cached (it always points at the current asset hashes)."""
    async def get_response(self, path, scope):
        resp = await super().get_response(path, scope)
        if path.startswith("assets/"):
            resp.headers["Cache-Control"] = "public, max-age=31536000, immutable"
        else:
            resp.headers["Cache-Control"] = "no-cache"
        return resp


app = FastAPI(title="Creator", lifespan=lifespan)

# gzip for the JS/CSS bundle + large JSON responses (~1.39 MB JS → ~400 KB).
app.add_middleware(GZipMiddleware, minimum_size=500)

app.include_router(router)

if FRONTEND_DIST.exists():
    app.mount("/", CachedStatic(directory=FRONTEND_DIST, html=True), name="frontend")