import os
from contextlib import asynccontextmanager

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

from db.init import init_database
from routers import documents, chat, auth
from core.config import settings


@asynccontextmanager
async def lifespan(app: FastAPI):
    await init_database()
    yield


app = FastAPI(title="RAG Backend API", lifespan=lifespan)

# Configure CORS — restrict to allowed origins from settings
app.add_middleware(
    CORSMiddleware,
    allow_origins=settings.allowed_origins_list,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Register routers
app.include_router(documents.router)
app.include_router(chat.router)
app.include_router(auth.router)


# Serve frontend static files in single-container mode (e.g. Hugging Face Spaces).
# Must be mounted AFTER all API routes to avoid catching API requests.
static_dir = os.path.join(os.path.dirname(__file__), "static")
if os.path.exists(static_dir):
    app.mount("/", StaticFiles(directory=static_dir, html=True), name="static")
else:
    @app.get("/")
    async def root():
        return {"status": "running"}


if __name__ == "__main__":
    import uvicorn

    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)