// Encryption.cpp : This file contains the 'main' function. Program execution begins and ends there.
#include "pch.h"
#include <iostream>
#include <fstream>
#include <string>
#include <vector>

#include <cstdint>
#define DELTA 0x9e3779b9
#define MX (((z>>5^y<<2) + (y>>3^z<<4)) ^ ((sum^y) + (key[(p&3)^e] ^ z)))

void btea(uint32_t *v, int n, uint32_t const key[4]) {
	uint32_t y, z, sum;
	unsigned p, rounds, e;
	if (n > 1) {          /* Coding Part */
		rounds = 6 + 52 / n;
		sum = 0;
		z = v[n - 1];
		do {
			sum += DELTA;
			e = (sum >> 2) & 3;
			for (p = 0; p < n - 1; p++) {
				y = v[p + 1];
				z = v[p] += MX;
			}
			y = v[0];
			z = v[n - 1] += MX;
		} while (--rounds);
	}
	else if (n < -1) {  /* Decoding Part */
		n = -n;
		rounds = 6 + 52 / n;
		sum = rounds * DELTA;
		y = v[0];
		do {
			e = (sum >> 2) & 3;
			for (p = n - 1; p > 0; p--) {
				z = v[p - 1];
				y = v[p] -= MX;
			}
			z = v[n - 1];
			y = v[0] -= MX;
			sum -= DELTA;
		} while (--rounds);
	}
}

int main(int argc, char** argv)
{
	std::cout << "you have entered" << argc << "arguments: " << "\n";
	for (auto i = 0; i < argc; ++i)
	{
		std::cout << argv[i] << "\n\n";
	}
	//uint32_t key[4];
	//key[3] = argv[2][3] - 48;
	//key[2] = argv[2][2] - 48;
	//key[1] = argv[2][1] - 48;
	//key[0] = argv[2][0] - 48;
	//const int n = 128 / sizeof(uint32_t);
	//char TestStr[128] = "1234567";
	//std::cout << "\nTest: \n";
	//printf("%s\n\n", TestStr);
	//btea(reinterpret_cast<uint32_t*>(TestStr), n, key);
	//std::cout << "Encrypted: \n";
	//printf("%s\n\n", TestStr);
	//btea(reinterpret_cast<uint32_t*>(TestStr), -n, key);
	//std::cout << "Decrypted: \n";
	//printf("%s\n\n", TestStr);

	//ENCRYPT OR DECRYPT COMMAND
	const auto opType = argv[1];
	std::vector<char> toProcess;

	//READING INPUT FILE
	const auto inputfile = argv[3];
	std::ifstream ifstreamFile;
	ifstreamFile.open(inputfile);
	if (ifstreamFile.is_open())
	{
		if (static_cast<std::string>(opType) == "Encrypt" || static_cast<std::string>(opType) == "encrypt")
		{
			std::cout << "Start encryption process >> \n";
			while (!ifstreamFile.eof())
			{
				toProcess.push_back(ifstreamFile.get());
			}
		}
		else if (static_cast<std::string>(opType) == "Decrypt" || static_cast<std::string>(opType) == "decrypt")
		{
			std::cout << "Start decryption process >> \n";
			while (!ifstreamFile.eof())
			{
				toProcess.push_back(ifstreamFile.get());
			}
		}
		else
			std::cout << "!!cmd argument 1 >> Operation type Invalid input!!";

		std::cout << "Input: \n";
		for (auto cha : toProcess)
		{
			std::cout << cha;
		}
		std::cout << '\n';
	}
	else
		std::cout << "Source File >> " << inputfile << " >> FAILED TO OPEN\n";
	ifstreamFile.close();

	//GETTING PASSWORD
	uint32_t key[4];
	key[3] = argv[2][3] - 48;
	key[2] = argv[2][2] - 48;
	key[1] = argv[2][1] - 48;
	key[0] = argv[2][0] - 48;


	//HANDLING PRE-ENCRYPTION
	const auto initSize = toProcess.size();
	const unsigned int c = 40;
	const int paddingsize = 4 - (toProcess.size() % 4);
	const auto cc = toProcess.size() + paddingsize;
	int nCounter = cc / sizeof(uint32_t);
	std::cout << "\nTo process>> \n";
	if (static_cast<std::string>(opType) == "Encrypt" || static_cast<std::string>(opType) == "encrypt")
	{
		toProcess.pop_back();
		for (unsigned int i = 0; i < cc; ++i)
		{
			if(i >= initSize - 1 && i < cc - 1)
			{
				toProcess.push_back('l');
			}
			else if (i == cc - 1)
			{
				toProcess.push_back(static_cast<char>(paddingsize));
			}
			//if (i >= ii - 1 && i < c -1)
			//{
			//	toProcess.push_back('l');
			//}
			//else if (i == c)
			//{
			//	toProcess.push_back(0);
			//}
			//else
			//{
			//	//toProcess[i] = inputChars[i];
			//}
			std::cout << toProcess[i];
		}
	}
	else if (static_cast<std::string>(opType) == "Decrypt" || static_cast<std::string>(opType) == "decrypt")
	{
		toProcess.pop_back();
		for (unsigned int i = 0; i < toProcess.size() - 1; ++i)
		{
			std::cout << toProcess[i];
		}
		nCounter = toProcess.size() / sizeof(uint32_t);
	}
	std::cout << '\n' << "InitSize: " << initSize << " :: Size: " << toProcess.size() << " :: nCounter: " << nCounter << '\n';

	//PROCESSING
	std::cout << "\nOutput>> \n";
	if (static_cast<std::string>(opType) == "Encrypt" || static_cast<std::string>(opType) == "encrypt")
	{
		btea(reinterpret_cast<uint32_t*>(toProcess.data()), nCounter, key);
		std::cout << toProcess.data() << std::endl;

		std::cout << '\n';
		for (auto i = 0; i < toProcess.size(); i++)
		{
			std::cout << toProcess[i];
		}

		std::cout << '\n';
	}
	else if (static_cast<std::string>(opType) == "Decrypt" || static_cast<std::string>(opType) == "decrypt")
	{
		btea(reinterpret_cast<uint32_t*>(&toProcess[0]), -nCounter, key);
		std::cout << &toProcess[0] << std::endl;
	/*	for (auto& toProces : toProcess)
		{
			if (toProces == 'l')
			{
				toProces = 0;
			}
		}*/
		std::cout <<"\n\nUn-Padded>>\n" << &toProcess[0] << std::endl;
	}

	//if (static_cast<std::string>(opType) == "Decrypt" || static_cast<std::string>(opType) == "decrypt")
	//{
	//	//HANDLING POST-DECRYPTION
	//	for (auto i = 0; i < 5; ++i)
	//	{
	//		toProcess.pop_back();
	//	}
	//	std::cout << "\n\nUn-Padded>>\n" << toProcess.data() << std::endl;
	//}

	std::cout << '\n' << "InitSize: " << initSize << " :: Size: " << toProcess.size() << " :: nCounter: " << nCounter << '\n';
	//WRITING OUTPUT FILE
	const auto outputfile = argv[4];
	std::ofstream ofstreamFile;
	ofstreamFile.open(outputfile);
	if (ofstreamFile.is_open())
	{
		//streamFile << &toProcess[0];
		for (char toProces : toProcess)
		{
			ofstreamFile << toProces;
			std::cout << toProces;
		}
	}
	else
		std::cout << "Source File >> " << outputfile << " >> FAILED TO OPEN\n";
	ofstreamFile.close();
	std::cout << '\n';

	std::cin.ignore();
	return 0;
}