"""
LightRAG Python Sidecar - Knowledge Graph Integration for LLM Gateway

FastAPI server providing hybrid knowledge graph RAG capabilities:
- Entity extraction & linking (LLM-powered)
- Hybrid retrieval (BM25 + vector similarity)
- Knowledge graph storage (PostgreSQL + Qdrant)
- Evaluation framework for retrieval quality
"""

from fastapi import FastAPI, HTTPException, BackgroundTasks
from fastapi.middleware.cors import CORSMiddleware
from contextlib import asynccontextmanager
import logging
import os

from app.config import settings
from app.db import init_db
from app.routes import query, ingest, eval, health

# 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 lifecycle management."""
    # Startup
    logger.info(f"Starting LightRAG Sidecar on port {settings.LIGHTRAG_PORT}")
    logger.info(f"Domain: {settings.LIGHTRAG_DOMAIN}")
    logger.info(f"LLM Backend: {settings.LLM_BACKEND}")
    logger.info(f"Database: {settings.DATABASE_URL}")
    logger.info(f"Qdrant: {settings.QDRANT_URL}")

    try:
        await init_db()
        logger.info("Database initialized successfully")
    except Exception as e:
        logger.error(f"Failed to initialize database: {e}")
        raise

    yield

    # Shutdown
    logger.info("Shutting down LightRAG Sidecar")


# Create app
app = FastAPI(
    title="LightRAG Sidecar",
    description="Knowledge Graph RAG integration for LLM Gateway",
    version="1.0.0",
    lifespan=lifespan
)

# CORS middleware for llm-gateway
app.add_middleware(
    CORSMiddleware,
    allow_origins=["http://localhost:3103", "http://192.168.178.82:3103"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Mount routers
app.include_router(health.router, prefix="/api/kg", tags=["health"])
app.include_router(query.router, prefix="/api/kg", tags=["query"])
app.include_router(ingest.router, prefix="/api/kg", tags=["ingest"])
app.include_router(eval.router, prefix="/api/kg", tags=["evaluation"])


@app.get("/", tags=["info"])
async def root():
    """API root endpoint."""
    return {
        "service": "LightRAG Sidecar",
        "version": "1.0.0",
        "domain": settings.LIGHTRAG_DOMAIN,
        "endpoints": {
            "health": "/api/kg/health",
            "query": "/api/kg/query",
            "ingest": "/api/kg/ingest",
            "eval": "/api/kg/eval",
        }
    }


if __name__ == "__main__":
    import uvicorn

    uvicorn.run(
        "app.main:app",
        host="0.0.0.0",
        port=settings.LIGHTRAG_PORT,
        reload=os.getenv("ENVIRONMENT") == "development"
    )