/**
 * Connection Validator Script
 *
 * This script tests your Neon database connection and provides diagnostic information.
 * Run with: npx ts-node validate-connection.ts
 *
 * Environment variables:
 * - DATABASE_URL: Your Neon connection string
 * - CONNECTION_TYPE: 'http' or 'websocket' (default: 'http')
 */

import { neon } from '@neondatabase/serverless';
import { Pool } from '@neondatabase/serverless';

const DATABASE_URL = process.env.DATABASE_URL;
const CONNECTION_TYPE = process.env.CONNECTION_TYPE || 'http';

if (!DATABASE_URL) {
  console.error('❌ DATABASE_URL environment variable is not set');
  process.exit(1);
}

async function validateHttpConnection() {
  console.log('\n🔍 Testing HTTP Connection...');
  try {
    const sql = neon(DATABASE_URL);

    // Test 1: Simple query
    console.log('  • Testing basic query...');
    const result = await sql`SELECT NOW() as current_time, version() as version`;
    console.log('  ✅ Query successful');

    // Test 2: Get database info
    console.log('  • Fetching database info...');
    const dbInfo = await sql`
      SELECT
        current_database() as database,
        current_user as user,
        version() as postgresql_version,
        (SELECT count(*) FROM information_schema.tables WHERE table_schema = 'public') as table_count
    `;

    console.log('\n📊 Database Information:');
    const info = dbInfo[0];
    console.log(`  • Database: ${info.database}`);
    console.log(`  • User: ${info.user}`);
    console.log(`  • PostgreSQL Version: ${info.postgresql_version.split(',')[0]}`);
    console.log(`  • Public Tables: ${info.table_count}`);

    // Test 3: Connection string validation
    console.log('\n🔐 Connection Details:');
    const url = new URL(DATABASE_URL);
    console.log(`  • Host: ${url.hostname}`);
    console.log(`  • Port: ${url.port || 5432}`);
    console.log(`  • Database: ${url.pathname.slice(1)}`);
    console.log(`  • SSL Mode: ${url.searchParams.get('sslmode') || 'require'}`);

    return true;
  } catch (error) {
    console.error('  ❌ Connection failed');
    console.error(`     Error: ${(error as any).message}`);
    return false;
  }
}

async function validateWebSocketConnection() {
  console.log('\n🔍 Testing WebSocket Connection...');
  try {
    const pool = new Pool({
      connectionString: DATABASE_URL,
      max: 1,
    });

    // Test 1: Get connection
    console.log('  • Acquiring connection...');
    const client = await pool.connect();
    console.log('  ✅ Connection acquired');

    try {
      // Test 2: Simple query
      console.log('  • Testing basic query...');
      const result = await client.query('SELECT NOW() as current_time, version() as version');
      console.log('  ✅ Query successful');

      // Test 3: Get database info
      console.log('  • Fetching database info...');
      const dbInfoResult = await client.query(`
        SELECT
          current_database() as database,
          current_user as user,
          version() as postgresql_version,
          (SELECT count(*) FROM information_schema.tables WHERE table_schema = 'public') as table_count
      `);

      console.log('\n📊 Database Information:');
      const info = dbInfoResult.rows[0];
      console.log(`  • Database: ${info.database}`);
      console.log(`  • User: ${info.user}`);
      console.log(`  • PostgreSQL Version: ${info.postgresql_version.split(',')[0]}`);
      console.log(`  • Public Tables: ${info.table_count}`);

      // Test 4: List tables
      console.log('\n📋 Public Tables:');
      const tablesResult = await client.query(`
        SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'
      `);

      if (tablesResult.rows.length > 0) {
        tablesResult.rows.forEach((row) => {
          console.log(`  • ${row.table_name}`);
        });
      } else {
        console.log('  (no tables found)');
      }
    } finally {
      client.release();
    }

    // Test 5: Connection string validation
    console.log('\n🔐 Connection Details:');
    const url = new URL(DATABASE_URL);
    console.log(`  • Host: ${url.hostname}`);
    console.log(`  • Port: ${url.port || 5432}`);
    console.log(`  • Database: ${url.pathname.slice(1)}`);
    console.log(`  • SSL Mode: ${url.searchParams.get('sslmode') || 'require'}`);

    await pool.end();
    return true;
  } catch (error) {
    console.error('  ❌ Connection failed');
    console.error(`     Error: ${(error as any).message}`);
    return false;
  }
}

async function main() {
  console.log('═══════════════════════════════════════════════════════');
  console.log('  Neon Connection Validator');
  console.log('═══════════════════════════════════════════════════════');

  console.log(`\n🚀 Testing ${CONNECTION_TYPE.toUpperCase()} connection...`);
  console.log(`   Database URL: ${DATABASE_URL.split('@')[1] || '...'}`);

  let success = false;

  if (CONNECTION_TYPE === 'websocket') {
    success = await validateWebSocketConnection();
  } else {
    success = await validateHttpConnection();
  }

  console.log('\n═══════════════════════════════════════════════════════');
  if (success) {
    console.log('✅ Connection validated successfully!');
    process.exit(0);
  } else {
    console.log('❌ Connection validation failed');
    console.log('\n💡 Troubleshooting tips:');
    console.log('   • Verify DATABASE_URL is correctly set');
    console.log('   • Check your Neon console for connection details');
    console.log('   • Ensure your firewall allows outbound connections');
    console.log('   • Check if SSL mode is correctly configured');
    process.exit(1);
  }
}

main().catch((error) => {
  console.error('Unexpected error:', error);
  process.exit(1);
});