#include <stdint.h>
#include <stddef.h>
#include <lib/image.h>
#include <lib/config.h>
#include <lib/misc.h>
#include <mm/pmm.h>
#include <lib/stb_image.h>

void image_make_centered(struct image *image, int frame_x_size, int frame_y_size, uint32_t back_colour) {
    image->type = IMAGE_CENTERED;

    image->x_displacement = (int64_t)frame_x_size / 2 - (int64_t)image->x_size / 2;
    image->y_displacement = (int64_t)frame_y_size / 2 - (int64_t)image->y_size / 2;
    image->back_colour = back_colour;
}


void image_make_stretched(struct image *image, int new_x_size, int new_y_size) {
    image->type = IMAGE_STRETCHED;

    image->x_size = new_x_size;
    image->y_size = new_y_size;
}

struct image *image_open(struct file_handle *file) {
    struct image *image = ext_mem_alloc(sizeof(struct image));

    image->type = IMAGE_TILED;

    void *src = ext_mem_alloc(file->size);

    fread(file, src, 0, file->size);

    int x, y, bpp;

    image->img = stbi_load_from_memory(src, file->size, &x, &y, &bpp, 4);

    pmm_free(src, file->size);

    if (image->img == NULL || x == 0 || y == 0) {
        if (image->img != NULL) {
            // stbi allocated but dimensions are degenerate
            pmm_free(image->img, (size_t)x * (size_t)y * 4);
        }
        pmm_free(image, sizeof(struct image));
        return NULL;
    }

    // Convert ABGR to XRGB
    uint32_t *pptr = (void *)image->img;
    size_t pixel_count = CHECKED_MUL((size_t)x, (size_t)y,
        ({ pmm_free(image, sizeof(struct image)); return NULL; }));
    for (size_t i = 0; i < pixel_count; i++) {
        pptr[i] = (pptr[i] & 0x0000ff00) | ((pptr[i] & 0x00ff0000) >> 16) | ((pptr[i] & 0x000000ff) << 16);
    }

    image->x_size = x;
    image->y_size = y;
    image->pitch = (int)CHECKED_MUL((size_t)x, 4,
        ({ pmm_free(image, sizeof(struct image)); return NULL; }));
    image->bpp = 32;
    image->img_width = x;
    image->img_height = y;

    return image;
}

void image_close(struct image *image) {
    stbi_image_free(image->img);
    pmm_free(image, sizeof(struct image));
}
