Fixed minor issues + added language support

ProjectManager.Frontend/src/app/services/lang.service.ts

@@ -0,0 +1,41 @@
+import { Injectable } from '@angular/core';
+import {Language} from "../entities/language";
+import {CrudService} from "./crud.service";
+import {firstValueFrom} from "rxjs";
+import {StorageService} from "./storage.service";
+
+@Injectable({
+  providedIn: 'root'
+})
+export class LangService {
+  private languages: Map<string, Language> = new Map<string, Language>();
+  public allLanguages: string[] = [];
+  public currentLang: Language;
+
+  constructor(private crud: CrudService, private storage: StorageService) {
+    this.loadLanguages();
+  }
+
+  private async loadLanguages() {
+    this.languages = new Map<string, Language>();
+    const res = await firstValueFrom(this.crud.client.get<{files: string[]}>(location?.origin + "/lang"));
+    const languages = res.files;
+    this.allLanguages = languages.map(lang => lang.replace(".json", ""));
+    const tasks = [];
+
+    for (let lang of languages) {
+      const task = firstValueFrom(this.crud.client.get<Language>(location?.origin + "/assets/languages/" + lang))
+        .then(result => this.languages.set(lang.replace(".json", ""), result));
+      tasks.push(task);
+    }
+
+    await Promise.all(tasks);
+    this.currentLang = this.languages.get(this.storage.getItem("language") || "en-US");
+  }
+
+  public setLanguage(lang: string) {
+    this.currentLang = this.languages.get(lang);
+    this.storage.setItem("language", lang);
+  }
+
+}