#include <image.h>
#include <string.h>
#include <iostream>
#include <string>
#include <GL/gl.h>


using namespace std;


Image :: Image() : width(0), height(0), depth(0), offset(0), buffer(NULL)
{
}


Image :: Image(int _w, int _h, int _d) : width(_w), height(_h), depth(_d), offset(1)
{
	buffer = new unsigned char[width * height * depth];
}


Image :: Image(const char * _filename) : width(0), height(0), depth(0), offset(0), buffer(NULL)
{
	load(_filename);
}


Image :: Image(const Image & _i) : width(_i.width), height(_i.height), depth(_i.depth), offset(_i.offset)
{
	buffer = malloc(width * height * depth * offset * sizeof(unsigned char));
	memcpy(buffer, _i.buffer, width * height * depth * offset * sizeof(unsigned char));
}


Image :: ~Image()
{
	clear();
}


void Image :: clear()
{
	if(buffer != NULL)
	{
		free(buffer);
		buffer = NULL;
	}
	
	width  = 0;
	height = 0;
	
	depth  = 0;
	offset = 0;
}


bool Image :: loadPNM(ifstream & _file)
{
	string magic, line;
	int type;
	
	_file >> magic;
	type = atoi(&magic[1]);
	if(magic[0] != 'P' &&  type < 1 && type > 6)
	{
		cerr << "[Image::loadPNG] Erreur. Le fichier n'est pas au format PNM (format : " << magic << "). Abandon du chargement." << endl;
		return false;
	}
	
	_file >> std::ws;
	while(_file.peek() == '#')
		getline(_file, line);
	
	_file >> width;
	_file >> height;
	_file >> offset;
	
	switch(type)
	{
		case 3 :
		case 6 :
			depth = 3;
			break;
		
		default :
			depth = 1;
			break;
	}
	
	if(width * height <= 0)
	{
		cerr << "[Image::loadPNG] Erreur. Les dimensions de l'image sont incorrectes (x : " << width << ", y : " << height << "). Abandon du chargement." << endl;
		return false;
	}
	
	if(offset <= 256)
		offset = 1;
	else
		offset = 2;
	
	buffer = malloc(width * height * depth * offset * sizeof(char));
	for(int j(height - 1); j > 0; j--)
		_file.read((char *)buffer + j * width * depth * offset, width * depth * offset * sizeof(char));
	
	return true;
}


bool Image :: load(const char * _filename)
{
	char * extension = strrchr(_filename, '.');
	ifstream file(_filename, ios::binary);
	
	if(file.is_open() == false)
	{
		cerr << "[Image::load] Erreur. Le fichier \"" << _filename << "\" est introuvable." << endl;
		return false;
	}
	
	if(strcmp(extension, ".pgm") == 0)
		return loadPNM(file);
		
	if(strcmp(extension, ".ppm") == 0)
		return loadPNM(file);
		
	if(strcmp(extension, ".pnm") == 0)
		return loadPNM(file);
	
	file.close();
	
	cerr << "[Image::load] Erreur. Le format du fichier \"" << _filename << "\" est inconnu." << endl;
	return false;
}


void Image :: display() const
{
	glRasterPos2i(0, 0);
	glDrawPixels(width, height, (depth == 1) ? GL_LUMINANCE : GL_RGB, (offset == 1) ? GL_UNSIGNED_BYTE : GL_UNSIGNED_SHORT, buffer);
}


int Image :: getWidth() const
{
	return width;
}


int Image :: getHeight() const
{
	return height;
}