typedef struct request_t {
  uint32_t cmd;
  uint32_t arg;
} request_t;

int64_t gnote_write(struct file *a1, const request_t *req, size_t a3,
                    loff_t *a4) {
  uint64_t len;
  note_data_t *req;
  void *new_note_data;

  mutex_lock(&lock);
  switch (req->cmd) {
    case 1:
      if ((uint64_t)cnt <= 7) {
        len = (uint32_t)req->arg;
        cur_note = &notes[cnt];
        cur_note->len = len;
        if (len <= 0x10000) {
          new_note_data = kmalloc(len, 0x6000C0LL);
          ++cnt;
          cur_note->data = new_note_data;
        }
      }
      break;
    case 2:
      printk("Edit Not implemented\n");
      break;
    case 3:
      printk("Delete Not implemented\n");
      break;
    case 4:
      printk("Copy Not implemented\n");
      break;
    case 5:
      if ((uint32_t)req->arg < (uint64_t)cnt) selected = (uint32_t)req->arg;
      break;
    default:
      break;
  }
  mutex_unlock(&lock);
  return a3;
}

uint64_t gnote_read(struct file *a1, char *a2, size_t len, loff_t *a4) {
  note_data_t *cur_note;

  mutex_lock(&lock);
  if (selected == -1) {
    mutex_unlock(&lock);
    return 0LL;
  } else {
    cur_note = &notes[selected];
    if (cur_note->len <= len) len = cur_note->len;
    copy_to_user(a2, cur_note->data, len);
    selected = -1LL;
    mutex_unlock(&lock);
    return len;
  }
}