/**
 * Migration: Add tenant_id to heartbeats table
 * This migration adds tenant_id field to heartbeats for multi-tenant support
 */

'use strict';

module.exports = {
  async up(queryInterface, Sequelize) {
    try {
      // Check if heartbeats table exists first
      const tables = await queryInterface.showAllTables();
      if (!tables.includes('heartbeats')) {
        console.log('⚠️  Heartbeats table does not exist yet, skipping heartbeat tenant support migration...');
        return;
      }

      // Check if tenant_id column already exists
      const tableDescription = await queryInterface.describeTable('heartbeats');
    
      if (!tableDescription.tenant_id) {
        // Add index for tenant_id for better query performance
        try {
          await queryInterface.addIndex('heartbeats', ['tenant_id'], {
            name: 'heartbeats_tenant_id_idx'
          });
          console.log('✅ Added index on heartbeats.tenant_id');
        } catch (error) {
          if (error.parent?.code === '42P07') { // Index already exists
            console.log('⚠️  Index heartbeats_tenant_id already exists, skipping...');
          } else {
            throw error;
          }
        }

        // Associate existing heartbeats with default tenant (backward compatibility)
        const defaultTenant = await queryInterface.sequelize.query(
          'SELECT id FROM tenants WHERE slug = :slug',
          {
            replacements: { slug: 'default' },
            type: Sequelize.QueryTypes.SELECT
          }
        );

        if (defaultTenant.length > 0) {
          await queryInterface.sequelize.query(
            'UPDATE heartbeats SET tenant_id = :tenantId WHERE tenant_id IS NULL',
            {
              replacements: { tenantId: defaultTenant[0].id },
              type: Sequelize.QueryTypes.UPDATE
            }
          );
          console.log('✅ Associated existing heartbeats with default tenant');
        }

        console.log('✅ Added tenant_id field to heartbeats table');
      } else {
        console.log('⚠️  Column tenant_id already exists in heartbeats table, skipping...');
      }
    } catch (error) {
      console.log('⚠️  Migration skipped - tables may not exist yet:', error.message);
      // Don't throw error, just skip this migration if tables don't exist
    }
  },

  async down(queryInterface, Sequelize) {
    // Remove index
    try {
      await queryInterface.removeIndex('heartbeats', 'heartbeats_tenant_id_idx');
    } catch (error) {
      console.log('⚠️  Index heartbeats_tenant_id_idx does not exist, skipping...');
    }

    // Remove column
    await queryInterface.removeColumn('heartbeats', 'tenant_id');
    console.log('✅ Removed tenant_id field from heartbeats table');
  }
};