from __future__ import annotations

import base64
import hashlib
import hmac
import secrets


def hash_password(password: str, salt: str | None = None) -> str:
    salt_value = salt or secrets.token_hex(16)
    derived = hashlib.pbkdf2_hmac(
        "sha256",
        password.encode("utf-8"),
        salt_value.encode("utf-8"),
        200_000,
    )
    digest = base64.b64encode(derived).decode("utf-8")
    return f"pbkdf2_sha256${salt_value}${digest}"


def verify_password(password: str, password_hash: str) -> bool:
    algorithm, salt, digest = password_hash.split("$", 2)
    if algorithm != "pbkdf2_sha256":
        return False
    expected = hash_password(password, salt=salt)
    return hmac.compare_digest(expected, password_hash)


def generate_session_token() -> str:
    return f"iron_{secrets.token_urlsafe(32)}"


def hash_session_token(token: str) -> str:
    return hashlib.sha256(token.encode("utf-8")).hexdigest()