app/main.py

import logging
import os
from fastapi import FastAPI, HTTPException, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
from fastapi.responses import JSONResponse, RedirectResponse
from pathlib import Path

from app.routers import rag

# Setup logging
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s - %(levelname)s - %(message)s",
    handlers=[
        logging.StreamHandler(),
        logging.FileHandler("logs/app.log"),
    ]
)
logger = logging.getLogger(__name__)

# Create the FastAPI app
app = FastAPI(
    title="RAG Research Assistant API",
    description="API for a Retrieval Augmented Generation system for research papers",
    version="1.0.0",
)

# Configure CORS settings
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # In production, replace with specific origins
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Include routers
app.include_router(rag.router)

# Root path handler - add this for Hugging Face Spaces
@app.get("/")
async def root():
    """Root endpoint that redirects to docs"""
    return {
        "message": "Welcome to the RAG Research Assistant API",
        "documentation": "/docs",
        "endpoints": {
            "rag": "/rag/query",
            "health": "/health"
        }
    }

# Mount static files if frontend exists
frontend_build_path = Path("../frontend/build")
if frontend_build_path.exists():
    app.mount("/static", StaticFiles(directory=str(frontend_build_path)), name="frontend")

@app.get("/health")
async def health_check():
    """Simple health check endpoint"""
    return {"status": "healthy"}

@app.on_event("startup")
async def startup_event():
    """Startup event handler"""
    # Ensure logs directory exists
    Path("logs").mkdir(exist_ok=True)
    logger.info("Application started")

@app.on_event("shutdown")
async def shutdown_event():
    """Shutdown event handler"""
    logger.info("Application shut down")

if __name__ == "__main__":
    import uvicorn
    # Determine port from environment or use default
    port = int(os.environ.get("PORT", 7860))
    
    # Run the application using Uvicorn
    uvicorn.run("app.main:app", host="0.0.0.0", port=port, reload=True)