#PypherStream/Caesar.py
#Matthew Ellison
# Created: 03-30-19
#Modified: 03-30-19
#This file contains the Caesar class for the PypherStream Project.
#This class takes input and uses a Caesar Cipher to encode or decode a message.
#This is a Python port of the CipherStream program found at https://bitbucket.org/Mattrixwv/CipherStream


class Caesar:
	__version = "1.0"	#The current version number for the library
	def __init__(self):
		self.__inputString = ""	#The string that needs encoded/decoded
		self.__outputString = ""	#The encoded/decoded string
		self.__shift = 0	#The amount that you need to shift each letter
	#Sets shift and makes sure it is within the propper bounds
	def __setShift(self, shiftAmount: int):
		self.__shift = shiftAmount % 26
	#Sets the input string
	def __setInputString(self, inputString: str):
		self.__inputString = inputString
	#Encodes the inputString and stores the result in outputString
	def __encode(self) -> str:
		temp = 0	#A temperary holder for the current working character
		for cnt in range(0, len(self.__inputString)):
			temp = ord(self.__inputString[cnt])
			#If it is an upper case letter shift it and wrap if necessary
			if(chr(temp).isupper()):
				temp += self.__shift
				#Wrap around if the letter is now out of bounds
				if(temp < ord('A')):
					temp += 26
				elif(temp > ord('Z')):
					temp -= 26
			#If it is a lower case letter shift it and wrap if necessary
			elif(chr(temp).islower()):
				temp += self.__shift
				#Wrap around if the letter is now out of bounds
				if(temp < ord('a')):
					temp += 26
				elif(temp > ord('z')):
					temp -= 26

			#If it is whitespace, number, or punctuation just let it pass through
			#Add it to the output string
			self.__outputString += chr(temp)
		return self.__outputString
			
	#Decodes the inputString and stores the result in outputString
	def __decode(self) -> str:
		temp = 0
		for cnt in range(0, len(self.__inputString)):
			temp = ord(self.__inputString[cnt])
			#If it is an upper case letter shift it and wrap if necessary
			if(chr(temp).isupper()):
				temp -= self.__shift
				if(temp < ord('A')):
					temp += 26
				elif(temp > ord('Z')):
					temp -= 26
			#If it is a lower case letter shift it and wrap if necessary
			elif(chr(temp).islower()):
				temp -= self.__shift
				if(temp < ord('a')):
					temp += 26
				elif(temp > ord('z')):
					temp -= 26
			#If it is whitespace, number, or punctuation just let it pass through
			#Add it to the output string
			self.__outputString += chr(temp)
		return self.__outputString

	#Returns the inputString
	def getInputString(self) -> str:
		return self.__inputString
	#Returns the shift value
	def getShift(self) -> int:
		return self.__shift
	#Returns the outputString
	def getOutputString(self) -> str:
		return self.__outputString
	#Sets the shift and inputString and encodes the message
	def encode(self, shiftAmount: int, inputStr: str) -> str:
		self.reset()
		self.__setShift(shiftAmount)
		self.__setInputString(inputStr)
		return self.__encode()
	#Sets the shift and inputString and decodes the message
	def decode(self, shiftAmount: int, inputStr: str) -> str:
		self.reset()
		self.__setShift(shiftAmount)
		self.__setInputString(inputStr)
		return self.__decode()

	#Makes sure all of the variables are empty
	def reset(self):
		self.__inputString = self.__outputString = ""
		self.__shift = 0

	#Returns the version of the library
	@classmethod
	def getVersion(cls) -> str:
		return cls.__version

#This will run the appropriate commands if this script is called stand alone instead of with the rest of the PypherStream program
if __name__ == "__main__":
	NotImplemented