Files
medreport_mrb2b/packages/i18n/src/i18n.server.ts
2025-06-08 16:18:30 +03:00

152 lines
4.2 KiB
TypeScript

import { type InitOptions, createInstance } from 'i18next';
import resourcesToBackend from 'i18next-resources-to-backend';
import { initReactI18next } from 'react-i18next/initReactI18next';
/**
* Initialize the i18n instance on the server.
* This is useful for RSC and SSR.
* @param settings - the i18n settings
* @param resolver - a function that resolves the i18n resources
*/
export async function initializeServerI18n(
settings: InitOptions,
resolver: (language: string, namespace: string) => Promise<object>,
) {
const i18nInstance = createInstance();
const loadedNamespaces = new Set<string>();
await new Promise((resolve) => {
void i18nInstance
.use(
resourcesToBackend(async (language, namespace, callback) => {
try {
const data = await resolver(language, namespace);
loadedNamespaces.add(namespace);
return callback(null, data);
} catch (error) {
console.log(
`Error loading i18n file: locales/${language}/${namespace}.json`,
error,
);
return callback(null, {});
}
}),
)
.use({
type: '3rdParty',
init: async (i18next: typeof i18nInstance) => {
let iterations = 0;
const maxIterations = 100;
// do not bind this to the i18next instance until it's initialized
while (i18next.isInitializing) {
iterations++;
if (iterations > maxIterations) {
console.error(
`i18next is not initialized after ${maxIterations} iterations`,
);
break;
}
await new Promise((resolve) => setTimeout(resolve, 1));
}
initReactI18next.init(i18next);
resolve(i18next);
},
})
.init(settings);
});
const namespaces = settings.ns as string[];
// If all namespaces are already loaded, return the i18n instance
if (loadedNamespaces.size === namespaces.length) {
return i18nInstance;
}
// Otherwise, wait for all namespaces to be loaded
const maxWaitTime = 0.1; // 100 milliseconds
const checkIntervalMs = 5; // 5 milliseconds
async function waitForNamespaces() {
const startTime = Date.now();
while (Date.now() - startTime < maxWaitTime) {
const allNamespacesLoaded = namespaces.every((ns) =>
loadedNamespaces.has(ns),
);
if (allNamespacesLoaded) {
return true;
}
await new Promise((resolve) => setTimeout(resolve, checkIntervalMs));
}
return false;
}
const success = await waitForNamespaces();
if (!success) {
console.warn(
`Not all namespaces were loaded after ${maxWaitTime}ms. Initialization may be incomplete.`,
);
}
return i18nInstance;
}
/**
* Parse the accept-language header value and return the languages that are included in the accepted languages.
* @param languageHeaderValue
* @param acceptedLanguages
*/
export function parseAcceptLanguageHeader(
languageHeaderValue: string | null | undefined,
acceptedLanguages: string[],
): string[] {
// Return an empty array if the header value is not provided
if (!languageHeaderValue) return [];
const ignoreWildcard = true;
// Split the header value by comma and map each language to its quality value
return languageHeaderValue
.split(',')
.map((lang): [number, string] => {
const [locale, q = 'q=1'] = lang.split(';');
if (!locale) return [0, ''];
const trimmedLocale = locale.trim();
const numQ = Number(q.replace(/q ?=/, ''));
return [isNaN(numQ) ? 0 : numQ, trimmedLocale];
})
.sort(([q1], [q2]) => q2 - q1) // Sort by quality value in descending order
.flatMap(([_, locale]) => {
// Ignore wildcard '*' if 'ignoreWildcard' is true
if (locale === '*' && ignoreWildcard) return [];
const languageSegment = locale.split('-')[0];
if (!languageSegment) return [];
// Return the locale if it's included in the accepted languages
try {
return acceptedLanguages.includes(languageSegment)
? [languageSegment]
: [];
} catch {
return [];
}
});
}