freezmo/components/activities/MultipleChoice.tsx
Martin Dvorak 618ad5fb9c Add an English/Czech interface language switch
English stays the default; Czech is a full translation. Only the app chrome
is translated - notes and generated decks keep their own language, which is a
core feature, not a setting.

i18n
- lib/i18n-dict.ts: flat en/cs dictionaries (441 keys each), translate() and
  translatePlural() with real Czech plural rules (1 sada / 2-4 sady / 5+ sad).
  English is the default and the fallback for a missing key.
- lib/i18n.ts: browser store (freezmo.locale.v1), useI18n() hook, and the
  x-freezmo-locale header. The hook's t/plural are bound to the locale React
  is rendering with, so the first client render matches the server HTML and
  then re-renders in the stored language; module-level t is only for event
  handlers and non-React helpers.
- <html lang> follows the choice (inline script + setLocale).

UI
- Settings -> Language segmented control (English / Cestina), plus an EN/CS
  button on the key gate for first run.
- Every screen translated: sidebar, header, tab bar, library, deck cards,
  folder bar, create flow, all seven activities, study chrome, results,
  settings + health panel, API-key gate and help, install sheet, offline and
  the deck-not-found page.
- Plural-aware counts everywhere (decks, folders, activities, runs, photos,
  documents, pages, words, wrong attempts).

Server
- API routes and guards (generate, grade, health, http-guard, rate-limit,
  ollama error mapping) answer in the request's language, so error cards and
  the health panel never fall back to English mid-sentence.

Fixes
- A hydration mismatch when a non-default locale was stored silently dropped
  the .dark class after hydration; render-time t() is now bound to the
  hook's locale (UploadScreen.describeExtraction, ResultsScreen.answerFor,
  DeckCard's folder fallback).
- Bumped the service worker cache to freezmo-v4 for this deploy.

Tests: i18n 27/27 (gate toggle, persistence, html lang, Czech plurals,
settings switch) and a rebuilt regression suite 72/72 (English default,
library, create, all 7 activity types, results, settings, install sheet,
offline, PWA, security, Czech smoke).
2026-10-08 13:56:32 +00:00

102 lines
2.8 KiB
TypeScript

"use client";
import { useEffect, useState } from "react";
import { useI18n } from "@/lib/i18n";
import type { Activity } from "@/lib/schemas";
import {
ActivityHeader,
FeedbackPanel,
Hint,
OptionTile,
PromptCard,
QuestionText,
type ActivityComponentProps,
} from "./shared";
type MultipleChoiceActivity = Extract<Activity, { type: "multiple_choice" }>;
export function MultipleChoice({
activity,
active,
onAnswered,
onNext,
isLast,
}: ActivityComponentProps<MultipleChoiceActivity>) {
const { t } = useI18n();
const [selected, setSelected] = useState<number | null>(null);
const answered = selected !== null;
const choose = (index: number) => {
if (answered) return;
setSelected(index);
onAnswered(index === activity.correctIndex);
};
useEffect(() => {
if (!active || answered) return;
const onKey = (event: KeyboardEvent) => {
const target = event.target as HTMLElement | null;
if (target && /^(INPUT|TEXTAREA)$/.test(target.tagName)) return;
const index = Number.parseInt(event.key, 10) - 1;
if (index >= 0 && index < activity.options.length) {
event.preventDefault();
choose(index);
}
};
window.addEventListener("keydown", onKey);
return () => window.removeEventListener("keydown", onKey);
// eslint-disable-next-line react-hooks/exhaustive-deps
}, [active, answered, activity.options.length]);
const stateFor = (index: number): "idle" | "correct" | "wrong" | "dim" => {
if (!answered) return "idle";
if (index === activity.correctIndex) return "correct";
if (index === selected) return "wrong";
return "dim";
};
return (
<>
<ActivityHeader type="multiple_choice" topic={activity.topic} />
<PromptCard>
<QuestionText>{activity.question}</QuestionText>
</PromptCard>
<div className="flex flex-col gap-2.5" role="group" aria-label={t("activity.answerOptions")}>
{activity.options.map((option, index) => (
<OptionTile
key={option + index}
state={stateFor(index)}
disabled={answered}
onClick={() => choose(index)}
shortcut={String(index + 1)}
>
{option}
</OptionTile>
))}
</div>
{!answered ? <Hint>{t("mc.tipKeys")}</Hint> : null}
{answered ? (
<FeedbackPanel
correct={selected === activity.correctIndex}
explanation={activity.explanation}
xp={activity.xp}
isLast={isLast}
onNext={onNext}
detail={
selected === activity.correctIndex ? null : (
<>
{t("activity.correctAnswer")}{" "}
<span className="font-bold">{activity.options[activity.correctIndex]}</span>
</>
)
}
/>
) : null}
</>
);
}