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
from pydantic import BaseModel


load_dotenv()
app = FastAPI()

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


class NodeStatusRequest(BaseModel):
    node_name: str
    host: str
    port: int
    dbname: str
    user: str
    password: str



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
    )



#{
#     "host": "172.16.10.178",
#     "node_name = "node3",
#     "port": 5444,
#     "dbname": "postgres",
#     "user": "postgres",
#     "password": "postgres",
#     "connect_timeout": 3,
# }


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

    try:
        db_config = {
            "host": data.host,
            "port": data.port,
            "dbname": data.dbname,
            "user": data.user,
            "password": data.password,
            "connect_timeout": 3,
        }
        conn = psycopg2.connect(**db_config)

        conn.close()

        return {
            "node": data.node_name,
            "online": True,
            "status": "online"
        }

    except Exception as e:

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