import re


class CaesarCypherClass:
    """
    恺撒密码，提供以恺撒密码方法进行加密及解密的方法，加密方法使用CaesarEncode()函数，解密方法使用CaesarDecode()函数
    """

    def __init__(self, *args, **kwargs):
        pass

    @staticmethod
    def caesar_encode(s):
        """
        恺撒密码加密方法，需要提供需要加密的明文。
        """
        s_encode = ''
        for c in s:
            if 'a' <= c <= 'z':
                s_encode += chr(ord('a') + (ord(c) - ord('a') + 3) % 26)
            elif 'A' <= c <= 'Z':
                s_encode += chr(ord('A') + (ord(c) - ord('A') + 3) % 26)
            elif 0x4E00 <= ord(c) <= 0x9FA5:
                s_encode += chr(ord(c) + 3)
            elif '0' <= c <= '9':
                s_encode += chr(ord('0') + (ord(c) - ord('0') + 3) % 10)
            else:
                s_encode += c
        return s_encode

    @staticmethod
    def caesar_decode(s):
        """
        恺撒密码解密方法，需要提供需要解密的密文。
        """
        s_decode = ''
        for c in s:
            if 'a' <= c <= 'z':
                s_decode += chr(ord('a') + (ord(c) - ord('a') - 3) % 26)
            elif 'A' <= c <= 'Z':
                s_decode += chr(ord('A') + (ord(c) - ord('A') - 3) % 26)
            elif 0x4E00 <= ord(c) <= 0x9FA5:
                s_decode += chr(ord(c) - 3)
            elif '0' <= c <= '9':
                s_decode += chr(ord('0') + (ord(c) - ord('0') - 3) % 10)
            else:
                s_decode += c
        return s_decode


class Base64CypherClass:
    """
    Base64的加解密算法，最简单的加密方式，可加密短的文字、小图片、小文件，图片文件大小不宜超过10M
    """
    def __init__(self, *args, **kwargs):
        """
        Base64类初始化函数
        :param args:
        :param kwargs:
        """
        import importlib
        self.base64 = importlib.import_module('base64')
        self.os = importlib.import_module('os')
        self.time = importlib.import_module('time')
        self.re = importlib.import_module('re')

    @staticmethod
    def base64_encode_str(self, s):
        """
        Base64字符串加密
        :param self:
        :param s: 要加密的字符串
        :return: 加密后的字符串
        """
        return self.base64.b64encode(s.encode('utf-8'))

    @staticmethod
    def base64_decode_str(self, s):
        """
        Base64字符串解密，解密前先判断是否为Base64加密方式
        :param self:
        :param s: 要解密的字符串
        :return: 解密后的字符串
        """
        try:
            self.base64.b64decode(s)
            return self.base64.b64decode(s).decode('utf-8')
        except Exception as e:
            return f"base64解密失败，请确定加密方式是否正确。错误信息：{e}"

    @staticmethod
    def base64_encode_pic(self, pic):
        """
        Base64加密图片，路径不存在则返回"图片路径不存在"
        :param self:
        :param pic: 要加密的图片路径
        :return: 返回加密的base64字符
        """
        if self.os.path.exists(pic):
            with open(pic, 'rb') as f:
                read_pic = open(pic, 'rb')
                read_data = read_pic.read()
                read_pic.close()
            return self.base64.b64encode(read_data)
        else:
            return "图片路径不存在"

    @staticmethod
    def base64_decode_pic(self, pic_bs64):
        """
        Base64解密图片
        :param self:
        :param pic_bs64:
        :return: 返回图片路径
        """
        pic_path = f"upload/temp/pic{int(self.time.time())}"
        if self.os.path.exists(f"{pic_path}.jpg"):
            self.os.remove(f"{pic_path}.jpg")
        elif not self.os.path.exists("upload/temp/pic"):
            self.os.path.mkdir("upload/temp/pic")

        with open(f"{pic_path}.jpg", 'wb') as f:
            f.write(self.base64.b64decode(pic_bs64))

        return f"{pic_path}.jpg"