/**
 * Database test helper - manages test database lifecycle
 *
 * NOTE: The smartdata models use a global `db` singleton. This helper
 * ensures proper initialization and cleanup for tests.
 */

import * as plugins from '../../ts/plugins.ts';
import { testConfig } from '../test.config.ts';

// Test database instance - separate from production
let testDb: plugins.smartdata.SmartdataDb | null = null;
let testDbName: string = '';
let isConnected = false;

// We need to patch the global db export since models reference it
// This is done by re-initializing with the test config
import { initDb, closeDb } from '../../ts/models/db.ts';

/**
 * Initialize test database with unique name per test run
 */
export async function setupTestDb(config?: {
  mongoUrl?: string;
  dbName?: string;
}): Promise<void> {
  // If already connected, reuse the connection
  if (isConnected && testDb) {
    return;
  }

  const mongoUrl = config?.mongoUrl || testConfig.mongodb.url;

  // Generate unique database name for this test session
  const uniqueId = crypto.randomUUID().slice(0, 8);
  testDbName = config?.dbName || `${testConfig.mongodb.name}-${uniqueId}`;

  // Initialize the global db singleton with test configuration
  testDb = await initDb(mongoUrl, testDbName);
  isConnected = true;
}

/**
 * Clean up test database - deletes all documents from collections
 * This is safer than dropping collections which causes index rebuild issues
 */
export async function cleanupTestDb(): Promise<void> {
  if (!testDb || !isConnected) return;

  try {
    const collections = await testDb.mongoDb.listCollections().toArray();
    for (const col of collections) {
      // Delete all documents but preserve indexes
      await testDb.mongoDb.collection(col.name).deleteMany({});
    }
  } catch (error) {
    console.warn('[TestHelper] Error cleaning database:', error);
  }
}

/**
 * Teardown test database - drops database and closes connection
 */
export async function teardownTestDb(): Promise<void> {
  if (!testDb || !isConnected) return;

  try {
    // Drop the test database
    await testDb.mongoDb.dropDatabase();
    // Close the connection
    await closeDb();
    testDb = null;
    isConnected = false;
  } catch (error) {
    console.warn('[TestHelper] Error tearing down database:', error);
  }
}

/**
 * Clear specific collection(s) - deletes all documents
 */
export async function clearCollections(...collectionNames: string[]): Promise<void> {
  if (!testDb || !isConnected) return;

  for (const name of collectionNames) {
    try {
      await testDb.mongoDb.collection(name).deleteMany({});
    } catch {
      // Collection may not exist, ignore
    }
  }
}

/**
 * Get the current test database name
 */
export function getTestDbName(): string {
  return testDbName;
}

/**
 * Get the database instance for direct access
 */
export function getTestDb(): plugins.smartdata.SmartdataDb | null {
  return testDb;
}