backend/app/utils/security.py

"""
Security utilities - password hashing, JWT token handling.
"""
from passlib.context import CryptContext
from jose import JWTError, jwt
from datetime import datetime, timedelta
from typing import Optional
from ..config import settings

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


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


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


def create_access_token(data: dict, expires_delta: Optional[timedelta] = None) -> str:
    """Create a JWT access token."""
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(minutes=settings.JWT_EXPIRATION_MINUTES)
    
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, settings.JWT_SECRET, algorithm=settings.JWT_ALGORITHM)
    return encoded_jwt


def decode_access_token(token: str) -> Optional[dict]:
    """Decode and verify a JWT token."""
    try:
        payload = jwt.decode(token, settings.JWT_SECRET, algorithms=[settings.JWT_ALGORITHM])
        return payload
    except JWTError:
        return None


def create_password_reset_token(email: str) -> str:
    """Create a password reset token (time-limited)."""
    delta = timedelta(hours=1)
    return create_access_token({"sub": email, "type": "password_reset"}, delta)


def verify_password_reset_token(token: str) -> Optional[str]:
    """Verify password reset token and return email."""
    payload = decode_access_token(token)
    if payload and payload.get("type") == "password_reset":
        return payload.get("sub")
    return None