// PlacementTestPlaygrounds.cpp : This file contains the 'main' function. Program execution begins and ends there.
//Timo Nys
//16-11-2019

#include "pch.h"
#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>

std::string RunLengthCompress(const std::string& word);
float CalculateCompressionRatio(int originalCount, int newCount);

int main()
{
	std::ifstream fileToEncode;
	std::string fileName;
	//Prompt the user for a VALID filename to compress
	do
	{
		std::cout << "Give the name of file to be encoded. \n";
		std::cin >> fileName;

		fileToEncode.open(fileName + ".txt");

	} while (!fileToEncode.is_open());

	//Prompt the user how to name the file to compress to
	std::cout << "Give the name of file to write the compressed result to. \n";
	std::cin >> fileName;
	std::ofstream fileToCompressTo{ fileName + ".txt" };

	//Compress every word in the file
	std::string wordToEncode;

	if (fileToEncode.is_open())
	{
		int originalLetterCount{ 0 };
		int newLetterCount{ 0 };
		while (fileToEncode >> wordToEncode)
		{
			originalLetterCount += wordToEncode.length();
			std::string compressedResult = RunLengthCompress(wordToEncode);
			fileToCompressTo << compressedResult << ' '; //Parse the compressed result to the compressed file and add a space between individual words
			newLetterCount += compressedResult.length() ;

		}
		//Print the compression rate
		float compressionRatio = CalculateCompressionRatio(originalLetterCount, newLetterCount);
		std::cout << std::setprecision(4) << compressionRatio;
	}

	return 0;
}

std::string RunLengthCompress(const std::string& word)
{
	std::string compressed{ "" };
	std::string toCompress{ word };//cache it in local memory
	size_t wordLength = word.length();

	for (size_t i = 0; i < wordLength; ++i)
	{
		int amount{ 1 };//init at 1 cause the character/number will always appear at least once
		while (i < wordLength - 1 && toCompress[i] == toCompress[i + 1])
		{
			++amount;
			++i;
		}
		compressed += std::to_string(amount) + toCompress[i];
	}
	return compressed;
}

float CalculateCompressionRatio(int originalCount, int newCount)
{
	return float(originalCount) / float(newCount);
}