'use strict';

module.exports = {
  async up(queryInterface, Sequelize) {
    // Add completed_at column to tasks table
    await queryInterface.addColumn('tasks', 'completed_at', {
      type: Sequelize.DATE,
      allowNull: true
    });
    
    // Add an index for better query performance
    await queryInterface.addIndex('tasks', ['completed_at']);
  },

  async down(queryInterface, Sequelize) {
    // Remove the index first
    await queryInterface.removeIndex('tasks', ['completed_at']);
    
    // Remove the completed_at column
    await queryInterface.removeColumn('tasks', 'completed_at');
  }
};