How to mock Argon2 password hashing in Python

import hashlib
import hmac
import os


class Argon2Mock:
    def __init__(self, salt_size=16, hash_len=32):
        self.salt_size = salt_size
        self.hash_len = hash_len
        
    def hash(self, password: str, salt: bytes = None) -> str:
        if salt is None:
            salt = os.urandom(self.salt_size)
        elif len(salt) != self.salt_size:
            raise ValueError(f"Salt must be {self.salt_size} bytes")
            
        # Mock Argon2 derivation: iterate HMAC-SHA256 to simulate hashing
        derived = salt
        for _ in range(10000):  # Simple iteration count
            derived = hmac.new(derived, password.encode(), hashlib.sha256).digest()
        
        derived = derived[:self.hash_len]
        return f"argon2$v=19$m=65536,t=3,p=4$" \
            f"{salt.hex()}$" \
            f"{derived.hex()}"
    
    def verify(self, password: str, encoded: str) -> bool:
        try:
            parts = encoded.split("$")
            salt_hex, hash_hex = parts[-2], parts[-1]
            salt = bytes.fromhex(salt_hex)
            expected = self.hash(password, salt)
            return hmac.compare_digest(expected, encoded)
        except Exception:
            return False


if __name__ == "__main__":
    argon = Argon2Mock()
    hashed = argon.hash("mySecretPass!42")
    print("Encoded:", hashed)
    print("Valid password:", argon.verify("mySecretPass!42", hashed))
    print("Invalid password:", argon.verify("wrongPass", hashed))