#-*-coding: utf-8 -*-
'''
 (1)작성자:김준현
                '''
import random
''' ---------- SETTING ---------- '''
TEMP_CEA_LIST=[]
AlphaBat_String=''
TEMP_SUB_LIST=[]
SUB_String=''
for symbol in range(97, 123):
    '''97, 98, 99, 100, ..., 122'''
    TEMP_CEA_LIST.append(chr(symbol))
    TEMP_SUB_LIST.append(chr(symbol))

while(True):
    random.shuffle(TEMP_SUB_LIST)
    if TEMP_SUB_LIST != TEMP_CEA_LIST:
        break

AlphaBat_String = ''.join(TEMP_CEA_LIST)
SUB_String = ''.join(TEMP_SUB_LIST)
'''---------------------------------'''

'''--------- ceasar cipher ---------'''
class ceasar:
    def __init__(self, p, k, c, pp):
        ''' p: 평서문, k: 비밀키(1~25), c: 암호문, pp:해독평문 '''
        self.p = p
        self.k = k
        self.c = c
        self.decryption_P = pp
    def plainText_encrypt(self):
        for charactor in self.p:
            if charactor in AlphaBat_String:
                index = AlphaBat_String.find(charactor) + self.k
                if index > len(AlphaBat_String)-1:
                    index = index % len(AlphaBat_String)
                self.c = self.c + AlphaBat_String[index]

            else:
                '''charactor not in AlphaBat_String'''
                self.c = self.c +charactor
        return self.c
    def cipherText_decrypt(self):
        for charactor in self.c:
            if charactor in AlphaBat_String:
                index = AlphaBat_String.find(charactor) - self.k
                if index < 0:
                    index = index + len(AlphaBat_String)
                self.decryption_P = self.decryption_P + AlphaBat_String[index]

            else:
                '''charactor not in AlphaBat_String'''
                self.decryption_P = self.decryption_P + charactor
        return self.decryption_P

'''--------- substitution cipher ---------'''
class substitutionCipher:
    def __init__(self, p, c, pp):
        self.p = p
        self.c = c
        self.decryption_P = pp
    def plainText_encrypt(self):
        for charactor in self.p:
            if charactor in AlphaBat_String:
                index = AlphaBat_String.find(charactor)
                self.c = self.c + SUB_String[index]

            else:
                '''charactor not in AlphaBat_String'''
                self.c = self.c +charactor
        return self.c
    def cipherText_decrypt(self):
        for charactor in self.c:
            if charactor in SUB_String:
                index = SUB_String.find(charactor)
                self.decryption_P = self.decryption_P + AlphaBat_String[index]

            else:
                '''charactor not in AlphaBat_String'''
                self.decryption_P = self.decryption_P +charactor
        return self.decryption_P

'''--------- vigenere cipher ---------'''
class vigenere:
     def __init__(self, p, k, c, pp):
        ''' p: 평서문, k: 비밀키(1~25), c: 암호문, pp:해독평문 '''
        self.p = p
        self.k = k
        self.c = c
        self.decryption_P = pp
     #cipherText = vigenere(plaintext, secretKey,cipherText,Result_plaintext).plainText_encrypt()
     def plainText_encrypt(self):
         i=0
         for charactor in self.p:
            if charactor in AlphaBat_String:
                index = AlphaBat_String.find(charactor) + AlphaBat_String.find(self.k[i])
                if index > len(AlphaBat_String)-1:
                    index = index % len(AlphaBat_String)
                self.c += AlphaBat_String[index]

            else:
                self.c += charactor

            i+=1
            if i >len(self.k)-1:
                i = 0

         return self.c

     def cipherText_decrypt(self):
         i=0
         for charactor in self.c:
            if charactor in AlphaBat_String:
                index = AlphaBat_String.find(charactor) - AlphaBat_String.find(self.k[i])
                if index <0 :
                    index = index + len(AlphaBat_String)
                self.decryption_P += AlphaBat_String[index]

            else:
                self.decryption_P += charactor

            i+=1
            if i >len(self.k)-1:
                i = 0

         return self.decryption_P

def main():
    plaintext = input("plaintext is ")
    plaintext = plaintext.lower()
    cipherText = ''
    Result_plaintext = ''

    print("(1): ceasar cipher      ")
    print("(2): substitution cipher")
    print("(3): vigenere cipher    ")


    while(True):
        result = int(input("result: "))
        #ceasar cipher
        if result == 1:
            secretKey = random.randint(1, 25)
            cipherText = ceasar(plaintext, secretKey,cipherText,Result_plaintext).plainText_encrypt()
            print("시저암호법: 평문[{0:s}]   -> 암호문[{1:s}] ". format(plaintext,cipherText))
            d = ceasar(plaintext, secretKey,cipherText,Result_plaintext).cipherText_decrypt()
            print("시저암호법: 암호문[{0:s}] -> 평문[{1:s}] ". format(cipherText,d))
            break
        #substitution cipher
        elif result == 2:
            cipherText = substitutionCipher(plaintext,cipherText,Result_plaintext).plainText_encrypt()
            print("대치암호법: 평문[{0:s}]   -> 암호문[{1:s}] ". format(plaintext,cipherText))
            d = substitutionCipher(plaintext,cipherText,Result_plaintext).cipherText_decrypt()
            print("대치암호법: 암호문[{0:s}] -> 평문[{1:s}] ". format(cipherText,d))
            break
        #vigenere cipher
        elif result == 3:
            secretKey_SIZE = random.randint(1, len(plaintext))
            secretKey = vigenere_secret_key_setting(secretKey_SIZE)
            cipherText = vigenere(plaintext, secretKey,cipherText,Result_plaintext).plainText_encrypt()
            print("비즈네르암호법: 평문[{0:s}]   -> 암호문[{1:s}] ". format(plaintext,cipherText))
            d = vigenere(plaintext, secretKey,cipherText,Result_plaintext).cipherText_decrypt()
            print("비즈네르암호법: 암호문[{0:s}] -> 평문[{1:s}] ". format(cipherText,d))
            break
        else:
            print("잘못입력했어")


def vigenere_secret_key_setting(secretKey_SIZE):
    size = 0
    tmp_key=''
    while(size!=secretKey_SIZE-1):
        tmp_key += AlphaBat_String[random.randint(0, len(AlphaBat_String)-1)]
        size +=1
    return tmp_key

if __name__=="__main__":
    main()