"""! @brief Defines the encryption class."""
##
# @file Vermasseln.py
#
# @brief Defines the Vermasseln class.
#
# @section description_vermasseln Description
# Defines the base class for the program encryption mechansim.
# - Vermasseln (base class)
#
# @section libraries_configloader Libraries/Modules
# - <a href="https://docs.python.org/3/library/platform.html">platform</a> Python standard library
#   - Access to underlying platform’s identifying data.
# - <a href="https://docs.python.org/3/library/base64.html">base64</a> Python standard library
#   - Provides functions for encoding binary data to printable ASCII characters and decoding such encodings back to binary data.
# - <a href="https://docs.python.org/3/library/random.html">random</a> Python module
#   -  Implements pseudo-random number generators for various distributions.
# - <a href="https://docs.python.org/3/library/string.html">string</a> Python standard library
#   - Common string operations.
# - <a href="https://pycryptodome.readthedocs.io/en/latest/src/api.html">Crypto</a> Python package
#   - Provides cryptographic functionalities.
#
# @section notes_vermasseln Notes
# - None.
#
# @section todo_vermasseln TODO
# - None.
#
# @section author_vermasseln Author(s)
# - Created by Linuxero on 03/14/2025.
# - Modified by Linuxero on 03/14/2025.
#
# Copyright (c) 2025 Schnaxero.  All rights reserved.

from Crypto.Cipher import AES
from base64 import b64encode, b64decode
import platform
from Crypto.Hash import SHA256, SHA3_512
# from Crypto.Protocol.KDF import PBKDF2
# from Crypto.Random import get_random_bytes
import random
import string


class Vermasseln:
    """! The Vermasseln class.
    Defines the class utilized by different parts of the program.
    Handles the encryption/decryption of the whole program.
    """
    def oscarVermasseln(self, data, local= True):
        """! Encrypts data.
        @param data The data to encrypt.
        @param local Is the encryption local to the host or not?
        @return  encrypted data.
        """
        b_data = data.encode("utf-8")
        cipher = self.__vermasslungsKobold(local)

        ciphertext, tag = cipher.encrypt_and_digest(b_data)
        decoded_data = [b64encode(x).decode("utf-8") for x in (ciphertext, tag)]
        storable_data = ".".join(decoded_data)

        return storable_data

    def entschluesseln(self, data, local = True):
        """! Decrypts data.
        @param data The data to decrypt.
        @param local Is the encryption local to the host or not?
        @return  decrypted data on success, None on failure.
        """
        try:
            data_list = data.split(".")
            encoded_data = [b64decode(x) for x in data_list]
            cipher = self.__vermasslungsKobold(local)
            decrypted_data = cipher.decrypt_and_verify(encoded_data[0], encoded_data[1])
            decrypted_data = decrypted_data.decode("utf-8")
        except (ValueError, IndexError) as e:
            print(f"Configuration corrupted: {str(e)}")
            decrypted_data = None

        except Exception as e:
            print(str(e))
            decrypted_data = None

        return decrypted_data

    def __vermasslungsKobold(self, local = True):
        """! Prepares the encryption key.
        @param local Is the encryption local to the host or not?
        @return  encryption key.
        """
        key = platform.processor().encode("utf-8") if local else b"(==daniishtverhaftetwegensexy#)"
        key = key[0:31]
        hash_key = SHA256.new(key)
        hashed = hash_key.digest()
        nonce = platform.machine().encode("utf-8") if local else b"(==Uskarishtverhaftetwegensexy#)"
        cipher = AES.new(hashed, AES.MODE_SIV, nonce = nonce)
        return cipher

    @classmethod
    def userPasswordHash(self, password, salt = None):
        """! Hashes data.
        @param password The data to hash.
        @param salt The salt to use if available.
        @return  hashed data.
        """
        if not salt:
            salt = "".join(random.choice(string.ascii_letters + string.digits) for i in range (32))
        hash_pw = (salt + password).encode("utf-8")
        h_obj = SHA3_512.new(hash_pw)
        password = salt + "$" + h_obj.hexdigest()
        return password