export function handleImagePaste(event: ClipboardEvent, onImage: (markdown: string) => void): void {
  const items = event.clipboardData?.items;
  if (!items) return;
  for (const item of Array.from(items)) {
    if (item.type.startsWith('image/')) {
      const file = item.getAsFile();
      if (!file) continue;
      event.preventDefault();
      const reader = new FileReader();
      reader.onload = (e) => onImage(`![image](${e.target!.result as string})`);
      reader.readAsDataURL(file);
      return;
    }
  }
}

export function insertAtSelection(
  textarea: HTMLTextAreaElement,
  currentValue: string,
  start: number,
  end: number,
  insertion: string,
): string {
  const next = currentValue.slice(0, start) + insertion + currentValue.slice(end);
  setTimeout(() => { textarea.selectionStart = textarea.selectionEnd = start + insertion.length; });
  return next;
}