import type { EditorState } from '@tiptap/pm/state'
import type { Node as PMNode } from '@tiptap/pm/model'

function isEmptyParagraph(node: PMNode): boolean {
  if (node.type.name !== 'paragraph') return false
  return node.textContent.trim() === '' && node.content.size <= 1
}

/** Paragraphe vide sous le curseur (critère US-3 Smart Paste). */
export function getEmptyParagraphAtSelection(
  state: EditorState,
): { pos: number; node: PMNode } | null {
  const { $from, empty } = state.selection
  if (!empty) return null
  if (!isEmptyParagraph($from.parent)) return null

  const pos = $from.before($from.depth)
  return { pos, node: $from.parent }
}