una/neo/apps/next/stubs/react-native-localize.js

// Smart stub for react-native-localize that uses browser locale on web.
// Date *order* must not read `navigator` during SSR/first paint — that is
// handled by `useDateLocaleTag` in packages/app/lib/util/datetime.ts.
const getBrowserLocale = () => {
    if (typeof navigator === 'undefined') {
        // Server-side fallback
        return { languageCode: 'en', countryCode: 'US', languageTag: 'en-US', isRTL: false };
    }

    // Client-side: get real browser locale
    const locale = navigator.language || navigator.userLanguage || 'en-US';
    const [languageCode, countryCode] = locale.split('-');

    return {
        languageCode: languageCode || 'en',
        countryCode: countryCode?.toUpperCase() || 'US',
        languageTag: locale,
        isRTL: false,
    };
};

const browserLanguage = typeof navigator === 'undefined'
    ? 'en-US'
    : navigator.language || 'en-US';

const browserNumberFormatter = typeof Intl === 'undefined'
    ? null
    : new Intl.NumberFormat(browserLanguage);

const browserDateTimeFormatter = typeof Intl === 'undefined'
    ? null
    : new Intl.DateTimeFormat(browserLanguage, { hour: 'numeric' });


export const getLocales = () => [getBrowserLocale()];

export const findBestLanguageTag = (languageTags) => {
    const browserLocale = getBrowserLocale();
    // Try to find matching language tag
    const match = languageTags?.find(tag =>
        tag.toLowerCase() === browserLocale.languageTag.toLowerCase()
    );
    return {
        languageTag: match || languageTags?.[0] || browserLocale.languageTag,
        isRTL: false,
    };
};

export const getNumberFormatSettings = () => {
    if (typeof navigator === 'undefined' || typeof Intl === 'undefined') {
        return { decimalSeparator: '.', groupingSeparator: ',' };
    }

    // Get real browser number format
    const formatter = browserNumberFormatter;
    const parts = formatter.formatToParts(1234.5);

    return {
        decimalSeparator: parts.find(p => p.type === 'decimal')?.value || '.',
        groupingSeparator: parts.find(p => p.type === 'group')?.value || ',',
    };
};

export const uses24HourClock = () => {
    if (!browserDateTimeFormatter) return false;
    const formatter = browserDateTimeFormatter;
    const parts = formatter.formatToParts(new Date(2020, 0, 1, 13));
    return !parts.some(part => part.type === 'dayPeriod');
};

export default {
    getLocales,
    findBestLanguageTag,
    getNumberFormatSettings,
    uses24HourClock,
};