/**
 * QA-C5: Auth storage module tests (replaces the Redux authSlice tests).
 *
 * Tests the sessionStorage-backed session persistence (WEB-C1):
 * - setAuthUser/getAuthUser round-trip
 * - getAuthUser tolerates malformed stored JSON
 * - clearAuth removes the stored session
 * - isTokenValid accepts unexpired JWTs and rejects expired/malformed ones
 */
import { describe, it, expect, beforeEach } from 'vitest';
import type { AuthUser } from '@proposal-system/api-contracts';
import { getAuthUser, setAuthUser, clearAuth, isTokenValid } from '../authStorage';
import { STORAGE_KEY_TOKEN } from '../../../constants';

function createToken(expOffsetSeconds: number): string {
  const header = btoa(JSON.stringify({ alg: 'HS256' }));
  const payload = btoa(JSON.stringify({
    sub: 'test-user',
    exp: Math.floor(Date.now() / 1000) + expOffsetSeconds,
  }));
  return `${header}.${payload}.fake-signature`;
}

const user: AuthUser = {
  id: 'user-1',
  email: 'admin@test.com',
  displayName: 'Admin',
  role: 'Admin',
  token: createToken(3600),
};

describe('authStorage', () => {
  beforeEach(() => {
    window.sessionStorage.clear();
  });

  it('QA-C5: setAuthUser persists to sessionStorage and getAuthUser reads it back', () => {
    setAuthUser(user);

    expect(window.sessionStorage.getItem(STORAGE_KEY_TOKEN)).not.toBeNull();
    expect(getAuthUser()).toEqual(user);
  });

  it('QA-C5: getAuthUser returns null when nothing is stored', () => {
    expect(getAuthUser()).toBeNull();
  });

  it('QA-C5: getAuthUser returns null for malformed stored JSON', () => {
    window.sessionStorage.setItem(STORAGE_KEY_TOKEN, 'not-valid-json{{{');

    expect(getAuthUser()).toBeNull();
  });

  it('QA-C5: clearAuth removes the stored session', () => {
    setAuthUser(user);
    clearAuth();

    expect(window.sessionStorage.getItem(STORAGE_KEY_TOKEN)).toBeNull();
    expect(getAuthUser()).toBeNull();
  });

  it('QA-C5: isTokenValid accepts a token expiring in the future', () => {
    expect(isTokenValid(createToken(3600))).toBe(true);
  });

  it('QA-C5: isTokenValid rejects an expired token', () => {
    expect(isTokenValid(createToken(-3600))).toBe(false);
  });

  it('isTokenValid accepts a base64url payload (JWT segments are base64url, not base64)', () => {
    // '>>>' encodes to 'Pj4-' in base64url — the '-' made the old atob() call throw.
    const payload = btoa(JSON.stringify({ sub: '>>>>>>', exp: Math.floor(Date.now() / 1000) + 3600 }))
      .replace(/\+/g, '-')
      .replace(/\//g, '_')
      .replace(/=+$/, '');
    expect(payload).toMatch(/[-_]/);

    expect(isTokenValid(`${btoa(JSON.stringify({ alg: 'HS256' }))}.${payload}.sig`)).toBe(true);
  });

  it('QA-C5: isTokenValid rejects missing or malformed tokens', () => {
    expect(isTokenValid(null)).toBe(false);
    expect(isTokenValid(undefined)).toBe(false);
    expect(isTokenValid('')).toBe(false);
    expect(isTokenValid('not-a-jwt')).toBe(false);
  });
});