Implement authentication logic

frontend/src/lib/i18n_store.ts

@@ -0,0 +1,55 @@
+import type { i18n } from 'i18next'
+import { writable, type Readable, type Writable } from 'svelte/store'
+
+export interface TranslationService {
+  i18n: Readable<i18n>
+}
+
+export const isLoading = writable(true)
+
+export class I18NextTranslationStore implements TranslationService {
+  public i18n: Writable<i18n>
+  public isLoading: Writable<boolean>
+
+  constructor(i18n: i18n) {
+    this.i18n = this.createInstance(i18n)
+    this.isLoading = this.createLoadingInstance(i18n)
+  }
+
+  private createInstance(i18n: i18n): Writable<i18n> {
+    const i18nWritable = writable(i18n)
+
+    i18n.on('initialized', () => {
+      i18nWritable.set(i18n)
+    })
+    i18n.on('loaded', () => {
+      i18nWritable.set(i18n)
+    })
+    i18n.on('added', () => i18nWritable.set(i18n))
+    i18n.on('languageChanged', () => {
+      i18nWritable.set(i18n)
+    })
+    return i18nWritable
+  }
+
+  private createLoadingInstance(i18n: i18n): Writable<boolean> {
+    // if loaded resources are empty || {}, set loading to true
+    i18n.on('loaded', (resources) => {
+      if (Object.keys(resources).length !== 0) {
+        isLoading.set(false)
+      }
+    })
+
+    // if resources failed loading, set loading to true
+    i18n.on('failedLoading', () => {
+      isLoading.set(true)
+    })
+
+    return isLoading
+  }
+}
+
+export const createI18nStore = (i18n: i18n) => {
+  const i18nStore = new I18NextTranslationStore(i18n)
+  return i18nStore.i18n
+}