CipherStream/SourceFiles/Caesar.cpp

//Ciphers/SourceFiles/Caesar.hpp
//Matthew Ellison
// Created: 4-25-18
//Modified: 5-5-18
//This file contains the implementation of the Caesar class
//This class implements the Caesar Cipher and is inteded to be turned into a library


#include "../Headers/Caesar.hpp"
#include <string>
#include <cctype>


Caesar::Caesar(){
	reset();
}

Caesar::~Caesar(){
}

void Caesar::setInputString(std::string input){
	inputString = input;
}

std::string Caesar::getInputString() const{
	return inputString;
}

void Caesar::setShift(int shiftAmount){
	//If you shift more than 26 you will just be wrapping back around again
	shift = shiftAmount % 26;
}

int Caesar::getShift() const{
	return shift;
}

std::string Caesar::getOutputString() const{
	return outputString;
}

std::string Caesar::encode(){
	char temp;	//A temperary holder for the current working character
	for(int cnt = 0;cnt < inputString.size();++cnt){
		temp = inputString.at(cnt);
		//If it is a upper case letter shift it and wrap if necessary
		if(isupper(temp)){
			temp += shift;
			//Wrap around if the letter is now out of bounds
			if(temp < 'A'){
				temp += 26;
			}
			else if(temp > 'Z'){
				temp -= 26;
			}
		}
		//If it is a lower case letter shift it and wrap if necessary
		else if(islower(temp)){
			temp += shift;
			//Wrap around if the letter is now out of bounds
			if(temp < 'a'){
				temp += 26;
			}
			else if(temp > 'z'){
				temp -= 26;
			}
		}
		//If it is whitespace, number, or punctuation just let it pass through
		//Add it to the output string
		outputString += temp;
	}
	return outputString;
}

std::string Caesar::encode(int shiftAmount, std::string input){
	setShift(shiftAmount);
	setInputString(input);
	return encode();
}

std::string Caesar::decode(){
	char temp;
	for(int cnt = 0;cnt < inputString.size();++cnt){
		temp = inputString.at(cnt);
		//If it is an upper case letter shift it and wrap if necessary
		if(isupper(temp)){
			temp -= shift;
			if(temp < 'A'){
				temp += 26;
			}
			else if(temp > 'Z'){
				temp -= 26;
			}
		}
		//If it is a lower case letter shift it and wrap if necessary
		else if(islower(temp)){
			temp -= shift;
			if(temp < 'a'){
				temp += 26;
			}
			else if(temp > 'z'){
				temp -= 26;
			}
		}
		//If it is whitespace, number, or punctuation just let it pass through
		//Add it to the output string
		outputString += temp;
	}
	return outputString;
}

std::string Caesar::decode(int shiftAmount, std::string input){
	setShift(shiftAmount);
	setInputString(input);
	return decode();
}

void Caesar::reset(){
	inputString = outputString = "";
	shift = 0;
}