Function countMatchesBefore

src/renderer/src/hooks/useSearchHighlight.ts:252–267

* 计算在同一消息中，当前匹配之前有多少个匹配

(messages: ChatMessage[], currentMatch: SearchMatch)

 * 计算在同一消息中，当前匹配之前有多少个匹配
 */
function countMatchesBefore(messages: ChatMessage[], currentMatch: SearchMatch): number {
  const messageContent = messages.find((m) => m.id === currentMatch.messageId)?.content ?? ''
  const matchText = messageContent.slice(currentMatch.startOffset, currentMatch.endOffset)

  let count = 0
  let searchIndex = 0

  while (searchIndex < currentMatch.startOffset) {
    const idx = messageContent.indexOf(matchText, searchIndex)
    if (idx === -1 || idx >= currentMatch.startOffset) break
    count++
    searchIndex = idx + 1
  }

  return count
}

/**
 * 根据拼接文本的偏移量创建 Range