from datetime import datetime, timedelta, timezone
from typing import Optional
from jose import jwt
from passlib.context import CryptContext
from ..core import config

# Use PBKDF2-SHA256 to avoid bcrypt's 72-byte limit and backend issues
pwd_context = CryptContext(schemes=["pbkdf2_sha256"], 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: str, expires_delta: Optional[timedelta] = None) -> str:
    if expires_delta is None:
        expires_delta = timedelta(days=7)
    expire = datetime.now(timezone.utc) + expires_delta
    to_encode = {"sub": subject, "exp": expire}
    return jwt.encode(to_encode, config.JWT_SECRET, algorithm=config.JWT_ALGORITHM)

def decode_token(token: str) -> Optional[str]:
    try:
        payload = jwt.decode(token, config.JWT_SECRET, algorithms=[config.JWT_ALGORITHM])
        return payload.get("sub")
    except Exception:
        return None