import type { LocalMessage } from 'stream-chat'

type MessageWithI18n = Pick<LocalMessage, 'text'> & {
  i18n?: Record<string, string> | null
}

export function normalizeLanguageCode(language?: string): string | undefined {
  const normalized = language?.trim().toLowerCase().split(/[-_]/)[0]
  return normalized || undefined
}

export function getMessageDisplayText({
  message,
  viewerLanguage,
}: {
  message?: MessageWithI18n | null
  viewerLanguage?: string
}): string | undefined {
  const fallbackText = message?.text
  const normalizedLanguage = normalizeLanguageCode(viewerLanguage)

  if (!normalizedLanguage) {
    return fallbackText
  }

  return message?.i18n?.[`${normalizedLanguage}_text`] ?? fallbackText
}