// Pure helpers for the public landing page, kept out of the Svelte component so
// the per-language Telegram-channel link selection is unit-testable.

import type { Locale } from './i18n/index.svelte';

/**
 * telegramChannelLink returns the t.me link for the locale's game channel, or null when it is
 * not configured. The channel usernames are build-time vars (VITE_TELEGRAM_GAME_CHANNEL_NAME_EN
 * / VITE_TELEGRAM_GAME_CHANNEL_NAME_RU) because the test and prod contours run different
 * channels; they are the same channels the connector posts to via TELEGRAM_GAME_CHANNEL_ID_*
 * (the id to post, the name to link). A leading "@" is tolerated.
 */
export function telegramChannelLink(locale: Locale): string | null {
  const raw =
    locale === 'ru'
      ? import.meta.env.VITE_TELEGRAM_GAME_CHANNEL_NAME_RU
      : import.meta.env.VITE_TELEGRAM_GAME_CHANNEL_NAME_EN;
  const name = (raw as string | undefined)?.trim().replace(/^@/, '');
  return name ? `https://t.me/${name}` : null;
}