theme draft 1

frontend/src/utils/localSettings.ts

@@ -0,0 +1,66 @@
+export type ThemeMode = 'light' | 'dark' | 'system';
+export type DocumentsViewMode = 'grid' | 'list';
+
+const LOCAL_SETTINGS_KEY = 'antholume:settings';
+
+interface LocalSettings {
+  themeMode?: ThemeMode;
+  documentsViewMode?: DocumentsViewMode;
+}
+
+function canUseLocalStorage(): boolean {
+  return typeof window !== 'undefined' && typeof window.localStorage !== 'undefined';
+}
+
+function readLocalSettings(): LocalSettings {
+  if (!canUseLocalStorage()) {
+    return {};
+  }
+
+  const rawValue = window.localStorage.getItem(LOCAL_SETTINGS_KEY);
+  if (!rawValue) {
+    return {};
+  }
+
+  try {
+    const parsedValue = JSON.parse(rawValue);
+    return typeof parsedValue === 'object' && parsedValue !== null ? parsedValue : {};
+  } catch {
+    return {};
+  }
+}
+
+function writeLocalSettings(settings: LocalSettings): void {
+  if (!canUseLocalStorage()) {
+    return;
+  }
+
+  window.localStorage.setItem(LOCAL_SETTINGS_KEY, JSON.stringify(settings));
+}
+
+function updateLocalSettings(partialSettings: LocalSettings): void {
+  writeLocalSettings({
+    ...readLocalSettings(),
+    ...partialSettings,
+  });
+}
+
+export function getThemeMode(): ThemeMode {
+  const settings = readLocalSettings();
+  return settings.themeMode === 'light' || settings.themeMode === 'dark'
+    ? settings.themeMode
+    : 'system';
+}
+
+export function setThemeMode(themeMode: ThemeMode): void {
+  updateLocalSettings({ themeMode });
+}
+
+export function getDocumentsViewMode(): DocumentsViewMode {
+  const settings = readLocalSettings();
+  return settings.documentsViewMode === 'list' ? 'list' : 'grid';
+}
+
+export function setDocumentsViewMode(documentsViewMode: DocumentsViewMode): void {
+  updateLocalSettings({ documentsViewMode });
+}