1 files changed, 80 insertions, 0 deletions
diff --git a/gui/src/shared/gettext.ts b/gui/src/shared/gettext.ts
new file mode 100644
index 0000000000..4722e16915
--- /dev/null
+++ b/gui/src/shared/gettext.ts
@@ -0,0 +1,80 @@
+import log from 'electron-log';
+import fs from 'fs';
+import { po } from 'gettext-parser';
+import Gettext from 'node-gettext';
+import path from 'path';
+
+const SOURCE_LANGUAGE = 'en';
+let SELECTED_LANGUAGE = SOURCE_LANGUAGE;
+const LOCALES_DIR = path.resolve(__dirname, '../../locales');
+
+// `{debug: false}` option prevents Gettext from printing the warnings to console in development
+// the errors are handled separately in the "error" handler below
+const catalogue = new Gettext({ debug: false });
+catalogue.setTextDomain('messages');
+catalogue.on('error', (error: string) => {
+  // Filter out the "no translation was found" errors for the source language
+  if (SELECTED_LANGUAGE === SOURCE_LANGUAGE && error.indexOf('No translation was found') !== -1) {
+    return;
+  }
+
+  log.warn(`Gettext error: ${error}`);
+});
+
+export function loadTranslations(currentLocale: string) {
+  // First look for exact match of the current locale
+  const preferredLocales = [];
+
+  if (currentLocale !== SOURCE_LANGUAGE) {
+    preferredLocales.push(currentLocale);
+  }
+
+  // In case of region bound locale like en-US, fallback to en.
+  const language = Gettext.getLanguageCode(currentLocale);
+  if (currentLocale !== language) {
+    preferredLocales.push(language);
+  }
+
+  for (const locale of preferredLocales) {
+    if (parseTranslation(locale, 'messages')) {
+      log.info(`Loaded translations for ${locale}`);
+      catalogue.setLocale(locale);
+
+      SELECTED_LANGUAGE = locale;
+      return;
+    }
+  }
+}
+
+function parseTranslation(locale: string, domain: string): boolean {
+  const filename = path.join(LOCALES_DIR, locale, `${domain}.po`);
+  let buffer: Buffer;
+
+  try {
+    buffer = fs.readFileSync(filename);
+  } catch (error) {
+    if (error.code !== 'ENOENT') {
+      log.error(`Cannot read the gettext file "${filename}": ${error.message}`);
+    }
+    return false;
+  }
+
+  let translations: object;
+  try {
+    translations = po.parse(buffer);
+  } catch (error) {
+    log.error(`Cannot parse the gettext file "${filename}": ${error.message}`);
+    return false;
+  }
+
+  catalogue.addTranslations(locale, domain, translations);
+
+  return true;
+}
+
+export const gettext = (msgid: string): string => {
+  return catalogue.gettext(msgid);
+};
+export const pgettext = (msgctx: string, msgid: string): string => {
+  return catalogue.pgettext(msgctx, msgid);
+};