whisher · May 24, 2019 08:47 · May 24, 2019
diff --git a/gistfile1.txt b/gistfile1.txt
@@ -0,0 +1,77 @@
+import { Injectable } from '@angular/core';
+
+import { TranslateService, LangChangeEvent } from '@ngx-translate/core';
+
+import { Logger } from '../logger';
+import enUS from '../../../translations/en-US.json';
+import itIT from '../../../translations/it-IT.json';
+
+const log = new Logger('I18nService');
+
+export function extract(s: string) {
+  return s;
+}
+
+@Injectable()
+export class I18nService {
+  languageKey = 'language';
+  defaultLanguage: string;
+  supportedLanguages: string[];
+
+  constructor(private translateService: TranslateService) {
+    translateService.setTranslation('en-US', enUS);
+    translateService.setTranslation('it-IT', itIT);
+  }
+
+  init(defaultLanguage: string, supportedLanguages: string[]) {
+    this.defaultLanguage = defaultLanguage;
+    this.supportedLanguages = supportedLanguages;
+    this.language = '';
+    this.translateService.onLangChange.subscribe((event: LangChangeEvent) => {
+      this.setLanguageKey(event.lang);
+    });
+  }
+
+  set language(language: string) {
+    language = this.getCurrentLanguage(language);
+    log.debug(`Language set to ${language}`);
+    this.translateService.use(language);
+  }
+
+  get language(): string {
+    return this.translateService.currentLang;
+  }
+
+  getCurrentLanguage(language: string): string {
+    language =
+      language ||
+      this.getLanguageKey() ||
+      this.translateService.getBrowserCultureLang();
+
+    let isSupportedLanguage = this.supportedLanguages.includes(language);
+
+    // If no exact match is found, search without the region
+    if (language && !isSupportedLanguage) {
+      language = language.split('-')[0];
+      language =
+        this.supportedLanguages.find(supportedLanguage =>
+          supportedLanguage.startsWith(language)
+        ) || '';
+      isSupportedLanguage = Boolean(language);
+    }
+
+    // Fallback if language is not supported
+    if (!isSupportedLanguage) {
+      language = this.defaultLanguage;
+    }
+    return language;
+  }
+
+  private setLanguageKey(current: string): void {
+    localStorage.setItem(this.languageKey, current);
+  }
+
+  private getLanguageKey(): string {
+    return localStorage.getItem(this.languageKey);
+  }
+}