import random
import string
from datetime import datetime, timedelta
from typing import Dict, Any, Optional, Union

from jose import JWTError, jwt
from passlib.context import CryptContext
from private_gpt.users.core.config import settings

ACCESS_TOKEN_EXPIRE_MINUTES = 60 * 24 * 1   # 12 hrs # Default Value
REFRESH_TOKEN_EXPIRE_MINUTES = 60 * 24 * 7 # 7 days  # Default Value
ALGORITHM = "HS256"
# JWT_SECRET_KEY = settings.SECRET_KEY
# JWT_REFRESH_SECRET_KEY = settings.REFRESH_KEY

JWT_SECRET_KEY = "QUICKGPT"
JWT_REFRESH_SECRET_KEY = "QUICKGPT_REFRESH"

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

def verify_password(plain_password: str, hashed_password: str) -> bool:
    return pwd_context.verify(plain_password, hashed_password)


def get_password_hash(password: str) -> str:
    return pwd_context.hash(password)


def create_access_token(subject: Union[str, Any], expires_delta: int = None) -> str:
    if expires_delta is not None:
        expires_delta = datetime.utcnow() + expires_delta
    else:
        expires_delta = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    
    to_encode = {"exp": expires_delta, **subject}
    encoded_jwt = jwt.encode(to_encode, JWT_SECRET_KEY, ALGORITHM)
    return encoded_jwt


def create_refresh_token(subject: Union[str, Any], expires_delta: int = None) -> str:
    if expires_delta is not None:
        expires_delta = datetime.utcnow() + expires_delta
    else:
        expires_delta = datetime.utcnow() + timedelta(minutes=REFRESH_TOKEN_EXPIRE_MINUTES)
    
    to_encode = {"exp": expires_delta, **subject}
    encoded_jwt = jwt.encode(to_encode, JWT_REFRESH_SECRET_KEY, ALGORITHM)
    return encoded_jwt

def generate_random_password(length: int = 12) -> str:
    """
    Generate a random password.
    """
    characters = string.ascii_letters + string.digits
    return ''.join(random.choice(characters) for i in range(length))


def verify_refresh_token(token: str) -> Optional[Dict[str, Any]]:
    try:
        payload = jwt.decode(token, JWT_REFRESH_SECRET_KEY,
                             algorithms=[ALGORITHM])
        return payload
    except JWTError:
        return None