#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <stdbool.h>

#define BUF_SIZE 256

int main(int argc, char* argv[]) {
  if (argc <= 1) {
    printf("Too few arguments\n");
    return 1;
  }

  const bool HAS_INCLUDES = argc > 2;
  char name[strlen(argv[1]) + 2];
  strcpy(name, argv[1]);
  strcat(name, ".c");

  char path[BUF_SIZE] = "./";

  strcat(path, name);

  open(path, O_RDONLY, 0);
  
  if (errno == 0) {
    printf("File already exists.\n");
    return 2;
  }
  errno = 0;

  const int fd = creat(path, S_IRUSR | S_IWUSR | S_IROTH);
  
  int includes_n = argc - 2;
  int lines_n = 4 + includes_n;

  char* lines[BUF_SIZE];

  int lines_i = 0;
  if (HAS_INCLUDES) {
    for (int i = 2; i < argc; i++) {
      char* line = (char*) malloc(BUF_SIZE);
      strcpy(line, "#include <");
      strcat(line, argv[i]);
      strcat(line, ".h>\n");

      lines[lines_i] = line;

      lines_i++;
    }

    lines[lines_i] = "\n";
    lines[++lines_i] = "int main() {\n\n";
    lines[++lines_i] = "  return 0;\n";
    lines[++lines_i] = "}";
  } else {
    lines[lines_i] = "int main() {\n\n";
    lines[++lines_i] = "  return 0;\n";
    lines[++lines_i] = "}";
    lines_n--;
  }

  for (int i = 0; i < lines_n; i++) {
    write(fd, lines[i], strlen(lines[i]));
  }

  close(fd);

  char command[5 + strlen(name)];
  strcpy(command, "nvim ");
  strcat(command, name);

  system(command);

  return 0;
}