import { expect, tap } from '@git.zone/tstest/tapbundle';
import * as smartdb from '../ts/index.js';
import { MongoClient, Db } from 'mongodb';
import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';

// ---------------------------------------------------------------------------
// Test: Missing data.rdb header recovery + startup logging
// Covers: ensure_data_header, BuildStats, info-level startup logging
// ---------------------------------------------------------------------------

let tmpDir: string;
let localDb: smartdb.LocalSmartDb;
let client: MongoClient;
let db: Db;

function makeTmpDir(): string {
  return fs.mkdtempSync(path.join(os.tmpdir(), 'smartdb-header-test-'));
}

function cleanTmpDir(dir: string): void {
  if (fs.existsSync(dir)) {
    fs.rmSync(dir, { recursive: true, force: true });
  }
}

// ============================================================================
// Setup: create data, then corrupt it
// ============================================================================

tap.test('setup: start, insert data, stop', async () => {
  tmpDir = makeTmpDir();
  localDb = new smartdb.LocalSmartDb({ folderPath: tmpDir });
  const info = await localDb.start();
  client = new MongoClient(info.connectionUri, {
    directConnection: true,
    serverSelectionTimeoutMS: 5000,
  });
  await client.connect();
  db = client.db('headertest');

  const coll = db.collection('docs');
  await coll.insertMany([
    { key: 'a', val: 1 },
    { key: 'b', val: 2 },
    { key: 'c', val: 3 },
  ]);

  await client.close();
  await localDb.stop();
});

// ============================================================================
// Delete hint file and restart: should rebuild from data.rdb scan
// ============================================================================

tap.test('header-recovery: delete hint file and restart', async () => {
  // Find and delete hint files
  const dbDir = path.join(tmpDir, 'headertest', 'docs');
  const hintPath = path.join(dbDir, 'keydir.hint');
  if (fs.existsSync(hintPath)) {
    fs.unlinkSync(hintPath);
  }

  localDb = new smartdb.LocalSmartDb({ folderPath: tmpDir });
  const info = await localDb.start();
  client = new MongoClient(info.connectionUri, {
    directConnection: true,
    serverSelectionTimeoutMS: 5000,
  });
  await client.connect();
  db = client.db('headertest');
});

tap.test('header-recovery: data intact after hint deletion', async () => {
  const coll = db.collection('docs');
  const count = await coll.countDocuments();
  expect(count).toEqual(3);

  const a = await coll.findOne({ key: 'a' });
  expect(a!.val).toEqual(1);
});

// ============================================================================
// Write new data after restart, stop, restart again
// ============================================================================

tap.test('header-recovery: write after hint-less restart', async () => {
  const coll = db.collection('docs');
  await coll.insertOne({ key: 'd', val: 4 });
  expect(await coll.countDocuments()).toEqual(4);
});

tap.test('header-recovery: restart and verify all data', async () => {
  await client.close();
  await localDb.stop();

  localDb = new smartdb.LocalSmartDb({ folderPath: tmpDir });
  const info = await localDb.start();
  client = new MongoClient(info.connectionUri, {
    directConnection: true,
    serverSelectionTimeoutMS: 5000,
  });
  await client.connect();
  db = client.db('headertest');

  const coll = db.collection('docs');
  const count = await coll.countDocuments();
  expect(count).toEqual(4);

  const keys = (await coll.find({}).toArray()).map(d => d.key).sort();
  expect(keys).toEqual(['a', 'b', 'c', 'd']);
});

// ============================================================================
// Cleanup
// ============================================================================

tap.test('header-recovery: cleanup', async () => {
  await client.close();
  await localDb.stop();
  cleanTmpDir(tmpDir);
});

export default tap.start();