import os
from contextlib import asynccontextmanager
from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from config import settings
from routes.documents import router as documents_router
from routes.chat import router as chat_router


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Application lifespan - create required directories on startup."""
    os.makedirs(settings.UPLOAD_DIR, exist_ok=True)
    os.makedirs(settings.CHROMA_DB_PATH, exist_ok=True)
    print("✅ RAG Assistant API started")
    print(f"   LLM Model: {settings.LLM_MODEL}")
    print(f"   Embedding Model: {settings.EMBEDDING_MODEL}")
    print(f"   ChromaDB Path: {settings.CHROMA_DB_PATH}")
    yield
    print("🛑 RAG Assistant API shutting down")


app = FastAPI(
    title="RAG Assistant API",
    description="A Retrieval-Augmented Generation assistant that answers questions from uploaded PDF documents.",
    version="1.0.0",
    lifespan=lifespan,
)

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

# Register routers
app.include_router(documents_router)
app.include_router(chat_router)




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


if __name__ == "__main__":
    import uvicorn

    uvicorn.run("main:app", host="0.0.0.0", port=8001, reload=True)