import { afterEach, describe, expect, it } from 'vitest';
import type { DecryptedMessage } from '@chat-app/shared/chat';

import {
  __resetForTests,
  getCachedMessages,
  hasCachedMessages,
  setCachedMessages,
} from './messageMemoryCache';

function msg(id: string): DecryptedMessage {
  return {
    id,
    conversationId: 'conv-1',
    senderId: 'sender-1',
    senderDeviceId: null,
    replyToId: null,
    editedAt: null,
    deletedAt: null,
    createdAt: '2026-05-17T00:00:00Z',
    plaintext: 'hi ' + id,
  };
}

describe('messageMemoryCache', () => {
  afterEach(() => {
    __resetForTests();
  });

  it('returns empty array when nothing is cached', () => {
    expect(getCachedMessages('unknown')).toEqual([]);
    expect(hasCachedMessages('unknown')).toBe(false);
  });

  it('stores and returns messages per conversation', () => {
    setCachedMessages('a', [msg('m1'), msg('m2')]);
    expect(getCachedMessages('a').map((m) => m.id)).toEqual(['m1', 'm2']);
    expect(hasCachedMessages('a')).toBe(true);
  });

  it('isolates conversations', () => {
    setCachedMessages('a', [msg('m1')]);
    setCachedMessages('b', [msg('m9')]);
    expect(getCachedMessages('a').map((m) => m.id)).toEqual(['m1']);
    expect(getCachedMessages('b').map((m) => m.id)).toEqual(['m9']);
  });

  it('overwrites prior cache when set again', () => {
    setCachedMessages('a', [msg('m1')]);
    setCachedMessages('a', [msg('m1'), msg('m2')]);
    expect(getCachedMessages('a').map((m) => m.id)).toEqual(['m1', 'm2']);
  });

  it('treats an explicit empty list as "cached"', () => {
    // A conversation that genuinely has zero messages should still be
    // flagged as cached so the hook skips the loading spinner on re-entry.
    setCachedMessages('a', []);
    expect(hasCachedMessages('a')).toBe(true);
    expect(getCachedMessages('a')).toEqual([]);
  });
});