| 1 | import { useCallback, useSyncExternalStore } from 'react'; |
| 2 | import { DEFAULT_PREFS, loadPrefs, type Lang } from '../game/prefs'; |
| 3 | |
| 4 | /** |
| 5 | * Which languages the labels are showing, held module-side rather than passed |
| 6 | * down: <Bi> is used at twenty-odd places across the table, and none of them |
| 7 | * has any other reason to know about the setting. |
| 8 | * |
| 9 | * The preference is the source of truth — App writes it here whenever it |
| 10 | * changes — but the first value is read straight from storage so a player who |
| 11 | * chose English does not watch the lobby repaint itself on every load. |
| 12 | */ |
| 13 | let lang: Lang = typeof window === 'undefined' ? DEFAULT_PREFS.lang : loadPrefs().lang; |
| 14 | |
| 15 | const listeners = new Set<() => void>(); |
| 16 | |
| 17 | const subscribe = (cb: () => void) => { |
| 18 | listeners.add(cb); |
| 19 | return () => { |
| 20 | listeners.delete(cb); |
| 21 | }; |
| 22 | }; |
| 23 | |
| 24 | export const getLang = () => lang; |
| 25 | |
| 26 | export function setLang(next: Lang) { |
| 27 | // <html lang> follows the labels, so a page showing English is not still |
| 28 | // claiming to be Chinese. index.html's notranslate stands either way. |
| 29 | if (typeof document !== 'undefined') { |
| 30 | document.documentElement.lang = next === 'en' ? 'en' : 'zh-TW'; |
| 31 | } |
| 32 | if (next === lang) return; |
| 33 | lang = next; |
| 34 | for (const cb of listeners) cb(); |
| 35 | } |
| 36 | |
| 37 | export function useLang(): Lang { |
| 38 | return useSyncExternalStore(subscribe, getLang, () => DEFAULT_PREFS.lang); |
| 39 | } |
| 40 | |
| 41 | /** |
| 42 | * One label in the language the table is being read in. |
| 43 | * |
| 44 | * The two strings stay side by side at the place they are used, which is how |
| 45 | * this codebase has always written them — there is no catalogue of keys to go |
| 46 | * and look a phrase up in, and adding one would put every label a file away |
| 47 | * from the thing it labels. |
| 48 | * |
| 49 | * `sep` is only ever seen in bilingual, and is whatever the line already used: |
| 50 | * a space for a button, ' · ' for a sentence with two halves. |
| 51 | */ |
| 52 | export function pick(lang: Lang, zh: string, en: string, sep = ' '): string { |
| 53 | if (lang === 'zh') return zh || en; |
| 54 | if (lang === 'en') return en || zh; |
| 55 | return zh && en ? zh + sep + en : zh || en; |
| 56 | } |
| 57 | |
| 58 | /** |
| 59 | * `pick` for a component, and the subscription that goes with it: a label built |
| 60 | * with this follows the setting rather than whatever it was on first render. |
| 61 | */ |
| 62 | export function useT() { |
| 63 | const lang = useLang(); |
| 64 | return useCallback((zh: string, en: string, sep?: string) => pick(lang, zh, en, sep), [lang]); |
| 65 | } |