import React from 'react'

const MARKER_RUNES = /\x02|\x03/g

/**
 * Splits a snippet string on \x02/\x03 marker runes and interleaves plain text
 * with `<mark>` elements for matched segments.
 *
 * Respects IV2 — no dangerouslySetInnerHTML, marker-rune split with React text
 * nodes only, safe against XSS.
 */
export function highlightSnippet(snippet: string): (string | React.JSX.Element)[] {
  const parts = snippet.split(MARKER_RUNES)
  const out: (string | React.JSX.Element)[] = []
  let inMatch = false
  for (const p of parts) {
    if (p === '') continue
    if (inMatch) out.push(React.createElement('mark', { key: out.length }, p))
    else out.push(p)
    inMatch = !inMatch
  }
  return out
}