from datetime import datetime, timedelta, timezone
from passlib.context import CryptContext
from jose import JWTError, jwt
from app.core.config import get_settings

settings = get_settings()

# Password hashing context
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")


def hash_password(password: str) -> str:
    """Hash a plain-text password using bcrypt."""
    return pwd_context.hash(password)


def verify_password(plain_password: str, hashed_password: str) -> bool:
    """Verify a plain-text password against a bcrypt hash."""
    return pwd_context.verify(plain_password, hashed_password)


def create_access_token(data: dict, expires_delta: timedelta | None = None) -> str:
    """
    Create a JWT access token.
    
    Args:
        data: Payload to encode (e.g. {"sub": user_id})
        expires_delta: Token expiration time
    
    Returns:
        Encoded JWT string
    """
    to_encode = data.copy()
    expire = datetime.now(timezone.utc) + (
        expires_delta or timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
    )
    to_encode.update({"exp": expire})
    return jwt.encode(to_encode, settings.SECRET_KEY, algorithm=settings.ALGORITHM)


def decode_access_token(token: str) -> dict | None:
    """
    Decode and validate a JWT token.
    
    Returns:
        Decoded payload dict, or None if invalid/expired
    """
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM])
        return payload
    except JWTError:
        return None