backend/main.py

"""FastAPI application for HF Agent web interface."""

import logging
import os
from contextlib import asynccontextmanager
from pathlib import Path

from dotenv import load_dotenv

load_dotenv()

# Ensure HF_TOKEN is set — fall back to HF_ADMIN_TOKEN if available (HF Spaces)
if not os.environ.get("HF_TOKEN") and os.environ.get("HF_ADMIN_TOKEN"):
    os.environ["HF_TOKEN"] = os.environ["HF_ADMIN_TOKEN"]

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

from routes.agent import router as agent_router
from routes.auth import router as auth_router

# Configure logging
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
)
logger = logging.getLogger(__name__)


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Application lifespan handler."""
    logger.info("Starting HF Agent backend...")
    yield
    logger.info("Shutting down HF Agent backend...")


app = FastAPI(
    title="HF Agent",
    description="ML Engineering Assistant API",
    version="1.0.0",
    lifespan=lifespan,
)

# CORS middleware for development
app.add_middleware(
    CORSMiddleware,
    allow_origins=[
        "http://localhost:5173",  # Vite dev server
        "http://localhost:3000",
        "http://127.0.0.1:5173",
        "http://127.0.0.1:3000",
    ],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Include routers
app.include_router(agent_router)
app.include_router(auth_router)

# Serve static files (frontend build) in production
static_path = Path(__file__).parent.parent / "static"
if static_path.exists():
    app.mount("/", StaticFiles(directory=str(static_path), html=True), name="static")
    logger.info(f"Serving static files from {static_path}")
else:
    logger.info("No static directory found, running in API-only mode")


@app.get("/api")
async def api_root():
    """API root endpoint."""
    return {
        "name": "HF Agent API",
        "version": "1.0.0",
        "docs": "/docs",
    }


if __name__ == "__main__":
    import uvicorn

    port = int(os.environ.get("PORT", 7860))
    uvicorn.run(app, host="0.0.0.0", port=port)