#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#include <cammy/image.h>
#include <cammy/photo.h>

#include "pnglite.h"
#include "png.h"
#include "commands.h"

static cammy_tile_palette palette = {
    .colors = {
        {   0,   0,   0 },
        {  85,  85,  85 },
        { 171, 171, 171 },
        { 255, 255, 255 }
    }
};

static void usage(int argc, char **argv, const char *message, ...) {
    if (message) {
        va_list args;

        va_start(args, message);
        vfprintf(stderr, message, args);
        va_end(args);
         fprintf(stderr, "\n");
    }

    fprintf(stderr, "usage: %1$s dither input.png output.png\n", argv[0]);

    exit(1);
}

int cammy_dither(int argc, char **argv) {
    uint8_t *bufin, *bufout;
    size_t width, height;
    int depth;

    if (argc < 3) {
        usage(argc, argv, "No PNG input file provided");
    } else if (argc < 4) {
        usage(argc, argv, "No PNG output filename provided");
    }

    if ((bufin = cammy_png_load(argv[2], &width,
                                &height,
                                &depth)) == NULL) {
        fprintf(stderr, "%s: %s: %s\n",
            argv[0], "cammy_png_load()", strerror(errno));

        goto error_png_load;
    }

    if ((bufout = malloc(width * height * 3)) == NULL) {
        fprintf(stderr, "%s: %s: %s\n",
            argv[0], "malloc()", strerror(errno));

        goto error_malloc_bufout;
    }

    cammy_image_dither(bufout, bufin, width, height, depth, &palette);

    if (cammy_png_save(argv[3], bufout,
                       width,
                       height, 8, PNG_TRUECOLOR) < 0) {
        fprintf(stderr, "%s: %s: %s: %s\n",
            argv[0], "cammy_png_save()", argv[3], strerror(errno));

        goto error_png_save;
    }

    free(bufout);

    free(bufin);

    return 0;

error_png_save:
    free(bufout);

error_malloc_bufout:
    free(bufin);

error_png_load:
    return 1;
}