import { HIGHLIGHT_SPAN_PATTERN } from '@admin/utils/editor/highlight-span-pattern'

export function findHighlightSpanRange(
  markdown: string,
  from: number,
  to: number
): { start: number; end: number; text: string } | null {
  HIGHLIGHT_SPAN_PATTERN.lastIndex = 0

  for (const match of markdown.matchAll(HIGHLIGHT_SPAN_PATTERN)) {
    const start = match.index
    const end = start + match[0].length
    const textStart = start + match[0].indexOf('>') + 1
    const textEnd = textStart + match[1].length
    const cursorInside = from === to && from >= start && from <= end
    const selectionInside = from >= textStart && to <= textEnd
    const selectionCovers = from <= start && to >= end

    if (cursorInside || selectionInside || selectionCovers) {
      return { start, end, text: match[1] }
    }
  }

  return null
}