import fs from 'node:fs/promises';
import os from 'node:os';
import path from 'node:path';
import { afterEach, describe, expect, it, vi } from 'vitest';
import { fallbackDashboardSnapshot } from '../../src/data/mockDashboard';
import { AuthService } from './auth';
import { buildRuntimePaths } from './config';
import { LiveSyncServer, buildSnapshotPatch } from './liveSync';

const cleanupDirs: string[] = [];

afterEach(async () => {
  vi.useRealTimers();
  await Promise.all(cleanupDirs.splice(0).map((dir) => fs.rm(dir, { recursive: true, force: true })));
});

describe('buildSnapshotPatch', () => {
  it('returns only changed top-level dashboard sections', () => {
    const nextSnapshot = {
      ...fallbackDashboardSnapshot,
      traffic: {
        ...fallbackDashboardSnapshot.traffic,
        totalBytes: fallbackDashboardSnapshot.traffic.totalBytes + 512,
      },
    };

    expect(buildSnapshotPatch(fallbackDashboardSnapshot, nextSnapshot)).toEqual({
      traffic: nextSnapshot.traffic,
    });
  });

  it('returns a full patch when no previous snapshot exists', () => {
    expect(buildSnapshotPatch(null, fallbackDashboardSnapshot)).toEqual({
      service: fallbackDashboardSnapshot.service,
      traffic: fallbackDashboardSnapshot.traffic,
      users: fallbackDashboardSnapshot.users,
      attention: fallbackDashboardSnapshot.attention,
      userRecords: fallbackDashboardSnapshot.userRecords,
      system: fallbackDashboardSnapshot.system,
    });
  });

  it('refreshes snapshots on the heartbeat even without file changes', async () => {
    vi.useFakeTimers();

    const rootDir = await fs.mkdtemp(path.join(os.tmpdir(), '3proxy-ui-live-sync-'));
    cleanupDirs.push(rootDir);

    const snapshotReader = vi.fn().mockResolvedValue(fallbackDashboardSnapshot);
    const server = new LiveSyncServer({
      auth: new AuthService({
        login: 'admin',
        password: 'proxy-ui-demo',
        ttlMs: 60_000,
      }),
      heartbeatMs: 50,
      runtime: {} as never,
      runtimePaths: buildRuntimePaths(rootDir),
      snapshotReader,
      store: {} as never,
    });

    await server.initialize();
    expect(snapshotReader).not.toHaveBeenCalled();

    await vi.advanceTimersByTimeAsync(50);
    expect(snapshotReader).toHaveBeenCalledTimes(1);

    server.close();
  });
});