#include <cstdint>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

static void print_usage(const char *name) {
  printf("Usage: %s -f <file_path> -w <width> -h <height>\n", name);
}

int main(int argc, char **argv) {
  const char *file_path = NULL;
  uint32_t resolution_width = 0;
  uint32_t resolution_height = 0;

  int opt;
  while ((opt = getopt(argc, argv, "f:w:h:")) != -1) {
    switch (opt) {
    case 'f':
      file_path = optarg;
      break;
    case 'w':
      sscanf(optarg, "%u", &resolution_width);
      break;
    case 'h':
      sscanf(optarg, "%u", &resolution_height);
      break;
    default:
      print_usage(argv[0]);
      return (EXIT_FAILURE);
    }
  }

  if (file_path == NULL || resolution_width <= 0 || resolution_height <= 0) {
    print_usage(argv[0]);
    return (EXIT_FAILURE);
  }

  // Open the file for read and write
  int fd = open(file_path, O_RDWR);
  if (fd == -1) {
    perror("Error opening file");
    return (EXIT_FAILURE);
  }

  // Get the size of the file
  struct stat file_stat;
  if (fstat(fd, &file_stat) == -1) {
    perror("Error getting file size");
    close(fd);
    return (EXIT_FAILURE);
  }

  off_t file_size = file_stat.st_size;

  // Map the file into memory
  void *mapped_data =
      mmap(NULL, file_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  if (mapped_data == MAP_FAILED) {
    perror("Error mapping file to memory");
    close(fd);
    return (EXIT_FAILURE);
  }

  // Now you can treat mapped_data as an array and edit its contents
  uint32_t *data = (uint32_t *)((u_int8_t *)mapped_data + 0x3C);

  printf("Old value: %u x %u\n", data[0], data[1]);

  if (resolution_width != 0) {
    data[0] = resolution_width;
  }
  if (resolution_height != 0) {
    data[1] = resolution_height;
  }

  printf("New value: %u x %u\n", data[0], data[1]);

  // Unmap the file from memory
  if (munmap(mapped_data, file_size) == -1) {
    perror("Error unmapping file from memory");
    close(fd);
    return (EXIT_FAILURE);
  }

  // Close the file descriptor
  close(fd);

  return 0;
}