from datetime import datetime, timedelta, timezone
from jose import JWTError, jwt, ExpiredSignatureError
from passlib.context import CryptContext
from app.config import *

settings = Settings()
SECRET_KEY = settings.jwt_secret
ALGORITHM="HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 10080  # 7 days

pwd_context = CryptContext(schemes=['argon2'], deprecated="auto")

def hash_password(password: str):
    return pwd_context.hash(password)

def verify_password(plain_password, hashed_password):
    return pwd_context.verify(plain_password, hashed_password)

def create_access_token(data: dict, expires_delta: timedelta | None = None):
    to_encode = data.copy()
    expire = datetime.now(timezone.utc) + (expires_delta or timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES))
    to_encode.update({"exp": expire})
    return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)

def decode_access_token(token: str):
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        return payload
    except ExpiredSignatureError:
        # Raise explicitly so backend knows token expired
        raise ExpiredSignatureError("Token Expired")
    except JWTError:
        # Any other JWT error (invalid signature, tampered, etc.)
        return None