#include "pam.h"
#include <stdio.h>
#include <string.h>

void write_p7_image(u64 width, u64 height, u8 *buf, const char *outfile) {
  FILE *fp = fopen(outfile, "wb");
  if (!fp) {
    fprintf(stderr, "Couldn't open file: %s\n", outfile);
    return;
  }

  char header[4096] = {0};
  snprintf(header, 4095,
           "P7\n"
           "WIDTH %lu\n"
           "HEIGHT %lu\n"
           "DEPTH 4\n"
           "MAXVAL 255\n"
           "TUPLTYPE RGB_ALPHA\n"
           "ENDHDR\n",
           width, height);

  u64 hdr_size = strlen(header);
  u64 buf_size = width * height * 4;

  fwrite(header, hdr_size, 1, fp);
  fwrite(buf, buf_size, 1, fp);

  fclose(fp);
}