from datetime import datetime, timedelta, timezone
from typing import Optional, Union
from jose import JWTError, jwt
from ea_chatbot.config import Settings

settings = Settings()

def create_access_token(data: dict, expires_delta: Optional[timedelta] = None) -> str:
    """
    Create a JWT access token.
    
    Args:
        data: The payload data to encode.
        expires_delta: Optional expiration time delta.
        
    Returns:
        str: The encoded JWT token.
    """
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(minutes=settings.access_token_expire_minutes)
    
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, settings.secret_key, algorithm=settings.algorithm)
    return encoded_jwt

def decode_access_token(token: str) -> Optional[dict]:
    """
    Decode a JWT access token.
    
    Args:
        token: The token to decode.
        
    Returns:
        Optional[dict]: The decoded payload if valid, None otherwise.
    """
    try:
        payload = jwt.decode(token, settings.secret_key, algorithms=[settings.algorithm])
        return payload
    except JWTError:
        return None