import os
import uvicorn
from dotenv import load_dotenv
from fastapi import FastAPI,Depends, Header, HTTPException, status
import psycopg2
from jwt import ExpiredSignatureError, InvalidTokenError
import jwt
load_dotenv()
app = FastAPI()

SECRET_KEY = os.getenv("SECRET_KEY")
ALGORITHM = os.getenv("ALGORITHM", "HS256")




def verify_token(
    authorization: str = Header(None),
):

    if not authorization:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Authorization header missing",
            headers={
                "WWW-Authenticate": "Bearer"
            },
        )

    parts = authorization.split()

    if len(parts) != 2:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid Authorization header",
        )

    scheme = parts[0]
    token = parts[1]

    if scheme.lower() != "bearer":
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Authorization scheme must be Bearer",
        )

    try:

        payload = jwt.decode(
            token,
            SECRET_KEY,
            algorithms=[ALGORITHM],
        )

        return payload

    except ExpiredSignatureError:

        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Token expired",
        )

    except InvalidTokenError:

        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid token",
        )
 





@app.get("/")
def root():
    return {"message": "PostgreSQL Agent is running"}



if __name__ == "__main__":
    host = os.getenv("HOST", "127.0.0.1")
    port = int(os.getenv("PORT", 9000))

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



DB_CONFIG = {
    "host": "172.16.10.178",
    "port": 5444,
    "dbname": "postgres",
    "user": "postgres",
    "password": "postgres",
    "connect_timeout": 3,
}

NODE_NAME = "node3"


@app.get("/node/status")
def node_status(token_data=Depends(verify_token)):

    try:
        conn = psycopg2.connect(**DB_CONFIG)

        conn.close()

        return {
            "node": NODE_NAME,
            "online": True,
            "status": "online"
        }

    except Exception as e:

        return {
            "node": NODE_NAME,
            "online": False,
            "status": "offline",
            "error": str(e)
        }