#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from hashlib import md5, sha1, sha256, blake2b
from zlib import crc32
from typing import Self, Protocol
from Interfaces.Application.CXCVInterface import CXCVInterface

class HashAlgorithm(Protocol):
    def update(self:Self, data:bytes) -> None: ...
    def hexdigest(self:Self) -> str: ...

class CRC32HashAlgorithm(HashAlgorithm):

    def __init__(self:Self) -> None:
        self.__value:int = 0

    def update(self:Self, data:bytes) -> None:
        self.__value = crc32(data, self.__value)

    def hexdigest(self:Self) -> str:
        return f"{self.__value & 0xFFFFFFFF:08x}"

class HashModel():

    def __init__(self:Self, cxcv:CXCVInterface, data:bytes = b"", chunk_size:int = 4096) -> None:
        
        self.cxcv:CXCVInterface = cxcv
        self.__chunk_size:int = chunk_size
        self.md5:str = ""
        self.sha1:str = ""
        self.sha256:str = ""
        self.blake2b:str = ""
        self.crc32:str = ""
        self.__hashes:list[HashAlgorithm] = ["md5", "sha1", "sha256", "blake2b", "crc32"]
        self.__algorithms:list[HashAlgorithm] = [
            method() for method in (md5, sha1, sha256, blake2b, CRC32HashAlgorithm)
        ]

        len(data) and self.update(data)

    def __update_chunk(self:Self, chunk:bytes) -> None:
        for hash_algorithm in self.__algorithms:
            hash_algorithm.update(chunk)

    def update(self:Self, data:bytes|str) -> None:

        done:bool = False

        if isinstance(data, bytes):

            while data:

                chunk:bytes = data[:self.__chunk_size]

                data = data[self.__chunk_size:]
                self.__update_chunk(chunk)

            done = True

        elif isinstance(data, str):
            self.cxcv.files.load_by_chunks(data, self.__update_chunk, self.__chunk_size)
            done = True

        if done:

            name:str

            for name in self.__hashes:
                setattr(self, name, getattr(self.__algorithms[self.__hashes.index(name)], "hexdigest")())