#include "IcoFormat.h"
#include <Spectre/System/ByteOrder.h>
#include <Spectre/Graphics/Image.h>
#include <Spectre/System/Log.h>
#include <cstdint>

namespace sp {
namespace image {

struct ICONDIRENT {
	uint8_t  width;			// pos 0
	uint8_t  height;			// pos 1
	uint8_t  num_colors;		// pos 2
	uint16_t color_planes;	// pos 4
	uint16_t bpp;			// pos 6
	uint32_t size;			// pos 8
	uint32_t offset;			// pos 12
};

struct ICONDIR {
	uint16_t reseved;
	uint16_t type;
	uint16_t num_images;
};

struct ICONDIRENT* findLargestImage(struct ICONDIRENT *ent, unsigned short size) {

	int cur_index = 0;
	unsigned int cur_size = 0;

	for (int i = 0; i < size; i++) {
		unsigned int sz = ent[i].width * ent[i].height;
		if (sz > cur_size) {
			cur_size = sz;
			cur_index = i;
		}
	}

	return ent + cur_index;
}

bool IcoFormat::decode(Image& img, const unsigned char *data, unsigned size)
{
	struct ICONDIRENT *ent;
	struct ICONDIRENT *largest;
	unsigned short type;		// pos 2
	unsigned short num_images;  // pos 4

	type 		= data[2] + data[3];
	num_images 	= data[4] + data[5];

	// 1 = ICO, 2 = CUR
	if (type != 0x0001 || num_images < 1) {
		return false;
	}

	// Allocate ICONDIRENT for all images in the file.
	ent = (struct ICONDIRENT *) malloc(sizeof(struct ICONDIRENT) * num_images);
	if (!ent) {
		return false;
	}

	for (int i = 0; i < num_images; i++) {
		unsigned int pos = 6 + (i*16);
		ent[i].width 		 = data[pos + 0];
		ent[i].height 		 = data[pos + 1];
		ent[i].num_colors 	 = data[pos + 2];
		ent[i].color_planes  = data[pos + 4];
		ent[i].bpp			 = data[pos + 6];
		ent[i].size		 	 = system::ltoh16(data + pos + 8);
		ent[i].offset		 = system::ltoh16(data + pos + 12);
	}

	// Find Largest image
	largest = findLargestImage(ent, num_images);

	sp::Log::info("%i, %i, %i, %i", largest->num_colors, largest->height, largest->offset, largest->size);
	sp::Log::info("%i", largest->bpp);


	img.loadFromMemory(data + largest->offset, largest->size);
	//img.create(PF_RGBA, largest->width, largest->height, data + largest->offset);

	free(ent);
	return true;
}

}} // namespace sp::image