/*
 * RLE - TP 1 du cours 8INF241 – Multimédia
 *
 * Copyright 2008 Michaël Larouche <larouche@kde.org>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include <iostream>
#include <fstream>

using namespace std;

static const char *input25Filename = "input25File.txt";
static const char *input100Filename = "input100File.txt";
static const char *out25Filename = "out25File.txt";
static const char *out100Filename = "out100File.txt";

void compressRle(fstream &input, fstream &output)
{
	char readChar;
	char currentChar;
	int numChar = 1;

	input >> readChar;
	currentChar = readChar;

	while( !input.eof() )
	{
		input >> readChar;

		if( readChar != currentChar || input.eof() )
		{
			// Write frequency,letter and separator to output
			output << numChar << currentChar << "/";
			// Reset currentChar and numChar
			numChar  = 1;
			currentChar = readChar;
		}
		else
		{
			numChar++;
		}
	}
}

int fileSize(fstream &file)
{
	int size = 0;

	file.seekg(0, ios_base::end);
	size = file.tellg();
	file.seekg(0, ios_base::beg);

	return size;
}

void showContent(fstream &file)
{
	file.seekg(0, fstream::beg);

	char temp;
	file >> temp;
	while( !file.eof() )
	{
		cout << temp;
		file >> temp;
	}

	cout << endl;
	file.clear();
}

void showCompressionRate(fstream &input, fstream &output)
{
	int inputFileSize = fileSize(input);
	int outputFileSize = fileSize(output);

	int compressionRate = static_cast<int>( (static_cast<float>(outputFileSize) / static_cast<float>(inputFileSize) ) * 100 );

	cout << "Taille du fichier initial: " << inputFileSize << endl;
	cout << "Taille du fichier code: " << outputFileSize << endl;
	cout << "Taux de compression: " << compressionRate << "%" << endl;
	cout << "Gain de compression: " << 100-compressionRate << "%" << endl;
}

int main(int argc, char **argv)
{
	cout << "Programme de compression de texte par principe de RLE" << endl;
	cout << "Par Michael Larouche <larouche@kde.org>" << endl << endl;

	// 25 character file
	fstream input25File(input25Filename, fstream::in);
	if( !input25File )
	{
		cerr << "Erreur lors de l'ouverture du fichier " << input25Filename << ". Verifiez les droits d'accès du fichier." << endl;
		return 1;
	}
	fstream out25File(out25Filename, fstream::out);
	if( !out25File )
	{
		cerr << "Erreur lors de l'ouverture du fichier " << out25Filename << ". Verifiez que vous avez les droits d'ecriture dans le repertoire." << endl;
	}

	// Do the RLE compression
	compressRle(input25File, out25File);

	// Clear the input file and re-open the out file as input
	input25File.clear();
	out25File.close();
	out25File.open(out25Filename, fstream::in );

	cout << "Pour le fichier à 25 caractères:" << endl;
	cout << "Contenue du fichier original:" << endl;
	showContent(input25File);
	cout << "Contenue du fichier code:" << endl;
	showContent(out25File);
	showCompressionRate(input25File, out25File);
	cout << endl;

	// 100 character file
	fstream input100File(input100Filename, fstream::in);
	if( !input100File )
	{
		cerr << "Erreur lors de l'ouverture du fichier " << input100Filename << ". Verifiez les droits d'accès du fichier." << endl;
		return 1;
	}

	fstream out100File(out100Filename, fstream::out);
	if( !out100File )
	{
		cerr << "Erreur lors de l'ouverture du fichier " << out100Filename << ". Verifiez que vous avez les droits d'ecriture dans le repertoire." << endl;
	}

	compressRle(input100File, out100File);
	input100File.clear();
	out100File.close();

	out100File.open(out100Filename, fstream::in );

	cout << "Pour le fichier à 100 caractères:" << endl;
	cout << "Contenue du fichier original:" << endl;
	showContent(input100File);
	cout << "Contenue du fichier code:" << endl;
	showContent(out100File);
	showCompressionRate(input100File, out100File);
	cout << endl;

	return 0;
}