#include "ff.h"
#include "../io/io.h"
#include "../cstr/cstr.h"
#include "../malloc/malloc.h"

#define MAGIC_VALUE "farbfeld"

u32 conv_to_int(u32 src)
{
	return ((src & 0xff) << 24) | ((src & 0xff00) << 8) | ((src & 0xff0000) >> 8) | ((src & 0xff000000) >> 24);
}

u32 read_u32_from_fd(int fd)
{
	u32 src;
	read(fd, (char *)&src, 4);

	return ((src & 0xff) << 24) | ((src & 0xff00) << 8) | ((src & 0xff0000) >> 8) | ((src & 0xff000000) >> 24);
}


image_t *new_image_from_fd(int fd)
{
	image_t *img = malloc(sizeof(image_t));
	char magic[9] = { 0 };

	read(fd, magic, 8);

	if (cstr_compare(magic, MAGIC_VALUE) != 0) {
		free(img);
		return 0;
	}

	img->width = read_u32_from_fd(fd);
	img->height = read_u32_from_fd(fd);

	if (img->width * img->height == 0) {
		free(img);
		return 0;
	}

	img->data = malloc(sizeof(image_pixel_t) * img->width * img->height);
	u64 s = 0;
	u64 rs = 0;
	while ((rs = read(fd, (char*)(img->data) + s, sizeof(image_pixel_t) * img->width * img->height - s))) {
		s += rs;
	}

	return img;
}


void free_image(image_t *img)
{
	free(img->data);
	free(img);
}

canvas_pixel_t image_pixel_to_canvas_pixel(image_pixel_t p)
{
	canvas_pixel_t cp;

	cp.r = p.r;
	cp.g = p.g;
	cp.b = p.b;
	cp.a = p.a;

	cp.r = (long double)(cp.r) * ((long double)(p.a) / 0xffff);
	cp.g = (long double)(cp.g) * ((long double)(p.a) / 0xffff);
	cp.b = (long double)(cp.b) * ((long double)(p.a) / 0xffff);

	return cp;
}