Localization support (#99)

* basic i18n poc

* translate home, filters, tabs

support dot notation in backend for namespaces

* i18n context menu, artist filters, list controls

also nothings here
fix backend not caching fallback

* i18n queue, artist view, search/results

* i18n settings and server view

* Added translation using Weblate (Norwegian Bokmål)

* Translated using Weblate (Norwegian Bokmål)

Currently translated at 100.0% (6 of 6 strings)

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/nb_NO/

* Update translation files

Updated by "Cleanup translation files" hook in Weblate.

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/

* Update translation files

Updated by "Cleanup translation files" hook in Weblate.

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/

* Update translation files

Updated by "Cleanup translation files" hook in Weblate.

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/

* fix url escaping

* added some mostly naive text overflow fixes

rewrote filter context menu as a slide in because the old one apparently can't handle dynamic width

* Added translation using Weblate (French)

* Translated using Weblate (French)

Currently translated at 17.4% (11 of 63 strings)

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/fr/

* Translated using Weblate (French)

Currently translated at 19.0% (12 of 63 strings)

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/fr/

* Translated using Weblate (French)

Currently translated at 40.0% (26 of 65 strings)

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/fr/

* add weblate and some pretty badges to readme

* fix link

* Translated using Weblate (French)

Currently translated at 50.7% (33 of 65 strings)

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/fr/

* Translated using Weblate (English)

Currently translated at 100.0% (65 of 65 strings)

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/en/

* Translated using Weblate (French)

Currently translated at 90.7% (59 of 65 strings)

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/fr/

* i18n now playing context type

fix overscroll on new filter menu
fix getting default namespace from the i18n backend

* Translated using Weblate (French)

Currently translated at 96.9% (63 of 65 strings)

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/fr/

* Translated using Weblate (French)

Currently translated at 100.0% (66 of 66 strings)

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/fr/

* Translated using Weblate (Japanese) (#98)

Currently translated at 7.5% (5 of 66 strings)

Translation: Subtracks/subtracks
Translate-URL: https://hosted.weblate.org/projects/subtracks/subtracks/ja/

Co-authored-by: Austin Riedhammer <4966622+austinried@users.noreply.github.com>

* little note to remind me why that's there

* update licenses

Co-authored-by: Allan Nordhøy <epost@anotheragency.no>
Co-authored-by: Hosted Weblate <hosted@weblate.org>
Co-authored-by: Clyhtsuriva <aimeric@adjutor.xyz>

app/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