minor reorg/cleanup

app/i18n/i18n.ts

@@ -0,0 +1,64 @@
+import { BackendModule, LanguageDetectorAsyncModule } from 'i18next'
+import path from 'path'
+import RNFS from 'react-native-fs'
+import * as RNLocalize from 'react-native-localize'
+import _ from 'lodash'
+
+const I18N_ASSETS_DIR = path.join('custom', 'i18n')
+
+const cache: {
+  [language: string]: {
+    [key: string]: any
+  }
+} = {}
+
+async function loadTranslation(language: string) {
+  const text = await RNFS.readFileAssets(path.join(I18N_ASSETS_DIR, `${language}.json`), 'utf8')
+  return JSON.parse(text)
+}
+
+async function readTranslation(language: string, namespace: string) {
+  if (!cache[language]) {
+    cache[language] = await loadTranslation(language)
+  }
+
+  return namespace === 'translation' ? cache[language] : _.get(cache[language], namespace)
+}
+
+export const backend = {
+  type: 'backend',
+  init: () => {},
+  read: async (language, namespace, callback) => {
+    try {
+      callback(null, await readTranslation(language, namespace))
+    } catch (err) {
+      callback(err as any, null)
+    }
+  },
+} as BackendModule
+
+export const languageDetector = {
+  type: 'languageDetector',
+  async: true,
+  detect: async callback => {
+    try {
+      const languageTags = (await RNFS.readDirAssets(I18N_ASSETS_DIR))
+        .map(f => f.name)
+        .filter(n => n.endsWith('.json'))
+        .map(n => n.slice(0, -5))
+
+      console.log('translations available:', languageTags)
+      console.log(
+        'locales list:',
+        RNLocalize.getLocales().map(l => l.languageTag),
+      )
+      console.log('best language:', RNLocalize.findBestAvailableLanguage(languageTags)?.languageTag)
+
+      callback(RNLocalize.findBestAvailableLanguage(languageTags)?.languageTag)
+    } catch {
+      callback(undefined)
+    }
+  },
+  init: () => {},
+  cacheUserLanguage: () => {},
+} as LanguageDetectorAsyncModule