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

'use strict';

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

      // Check if tenant_id column already exists
      const tableDescription = await queryInterface.describeTable('devices');
    
    if (!tableDescription.tenant_id) {
      // Add tenant_id column to devices table
      await queryInterface.addColumn('devices', 'tenant_id', {
        type: Sequelize.INTEGER,
        allowNull: true, // Nullable for backward compatibility
        references: {
          model: 'tenants',
          key: 'id'
        },
        onUpdate: 'CASCADE',
        onDelete: 'SET NULL',
        comment: 'Foreign key to tenants table for multi-tenant isolation'
      });

      // Add index for tenant_id for better query performance
      try {
        await queryInterface.addIndex('devices', ['tenant_id'], {
          name: 'devices_tenant_id_idx'
        });
        console.log('✅ Added index on devices.tenant_id');
      } catch (error) {
        if (error.parent?.code === '42P07') { // Index already exists
          console.log('⚠️  Index devices_tenant_id already exists, skipping...');
        } else {
          throw error;
        }
      }

      // Associate existing devices 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 devices SET tenant_id = :tenantId WHERE tenant_id IS NULL',
          {
            replacements: { tenantId: defaultTenant[0].id },
            type: Sequelize.QueryTypes.UPDATE
          }
        );
        console.log('✅ Associated existing devices with default tenant');
      }

      console.log('✅ Added tenant_id field to devices table');
    } else {
      console.log('⚠️  Column tenant_id already exists in devices table, skipping...');
    }
  },

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

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