refactor(frontend): extract reusable hooks and page helper modules

vite-frontend/src/utils/session.ts

@@ -0,0 +1,90 @@
+export const SESSION_STORAGE_KEYS = {
+  token: "token",
+  roleId: "role_id",
+  name: "name",
+  admin: "admin",
+} as const;
+
+export interface SessionData {
+  token: string | null;
+  roleId: number | null;
+  name: string | null;
+  isAdmin: boolean;
+}
+
+export interface LoginSessionPayload {
+  token: string;
+  role_id: number;
+  name: string;
+}
+
+const SESSION_EVENT_NAME = "sessionUpdated";
+
+const parseRoleId = (value: string | null): number | null => {
+  if (value === null) {
+    return null;
+  }
+
+  const roleId = Number.parseInt(value, 10);
+
+  return Number.isNaN(roleId) ? null : roleId;
+};
+
+export const getToken = (): string | null => {
+  return localStorage.getItem(SESSION_STORAGE_KEYS.token);
+};
+
+export const getRoleId = (): number | null => {
+  return parseRoleId(localStorage.getItem(SESSION_STORAGE_KEYS.roleId));
+};
+
+export const getSessionName = (): string | null => {
+  return localStorage.getItem(SESSION_STORAGE_KEYS.name);
+};
+
+export const getAdminFlag = (): boolean => {
+  const adminValue = localStorage.getItem(SESSION_STORAGE_KEYS.admin);
+
+  if (adminValue !== null) {
+    return adminValue === "true";
+  }
+
+  const roleId = getRoleId();
+  const isAdmin = roleId === 0;
+
+  if (roleId !== null) {
+    localStorage.setItem(SESSION_STORAGE_KEYS.admin, String(isAdmin));
+  }
+
+  return isAdmin;
+};
+
+export const readSession = (): SessionData => {
+  return {
+    token: getToken(),
+    roleId: getRoleId(),
+    name: getSessionName(),
+    isAdmin: getAdminFlag(),
+  };
+};
+
+export const writeLoginSession = (payload: LoginSessionPayload): void => {
+  localStorage.setItem(SESSION_STORAGE_KEYS.token, payload.token);
+  localStorage.setItem(SESSION_STORAGE_KEYS.roleId, String(payload.role_id));
+  localStorage.setItem(SESSION_STORAGE_KEYS.name, payload.name);
+  localStorage.setItem(
+    SESSION_STORAGE_KEYS.admin,
+    String(payload.role_id === 0),
+  );
+  window.dispatchEvent(new Event(SESSION_EVENT_NAME));
+};
+
+export const clearSession = (): void => {
+  localStorage.removeItem(SESSION_STORAGE_KEYS.token);
+  localStorage.removeItem(SESSION_STORAGE_KEYS.roleId);
+  localStorage.removeItem(SESSION_STORAGE_KEYS.name);
+  localStorage.removeItem(SESSION_STORAGE_KEYS.admin);
+  window.dispatchEvent(new Event(SESSION_EVENT_NAME));
+};
+
+export const SESSION_UPDATED_EVENT = SESSION_EVENT_NAME;