"""
Security utilities for authentication.
"""
import hashlib
from datetime import datetime, timedelta, timezone
from typing import Optional

import bcrypt
import jwt
from jwt.exceptions import PyJWTError

from app.core.config import get_settings

settings = get_settings()


def sha256_hash(password: str) -> str:
    """SHA-256 hash a raw password (matches client-side hashing)."""
    return hashlib.sha256(password.encode()).hexdigest()


def verify_password(sha256_password: str, hashed_password: str) -> bool:
    """Verify a SHA-256 hashed password against its bcrypt hash."""
    return bcrypt.checkpw(
        sha256_password.encode(), hashed_password.encode()
    )


def get_password_hash(raw_password: str) -> str:
    """Hash a raw password: SHA-256 then bcrypt."""
    return bcrypt.hashpw(
        sha256_hash(raw_password).encode(), bcrypt.gensalt()
    ).decode()


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.now(timezone.utc) + expires_delta
    else:
        expire = datetime.now(timezone.utc) + timedelta(
            minutes=settings.access_token_expire_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 access token."""
    try:
        payload = jwt.decode(
            token, settings.jwt_secret, algorithms=[settings.jwt_algorithm]
        )
        return payload
    except PyJWTError:
        return None