'use strict';

module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('task_prerequisites', {
      id:                   { type: Sequelize.UUID, defaultValue: Sequelize.UUIDV4, primaryKey: true },
      task_id:              { type: Sequelize.UUID, allowNull: false, references: { model: 'tasks', key: 'task_id' }, onDelete: 'CASCADE' },
      prerequisite_task_id: { type: Sequelize.UUID, allowNull: false, references: { model: 'tasks', key: 'task_id' }, onDelete: 'CASCADE' },
      createdAt:            { type: Sequelize.DATE, allowNull: false },
      updatedAt:            { type: Sequelize.DATE, allowNull: false },
    });

    await queryInterface.addIndex('task_prerequisites', { fields: ['task_id', 'prerequisite_task_id'], unique: true, name: 'uq_task_prerequisite' });
    await queryInterface.addIndex('task_prerequisites', { fields: ['task_id'], name: 'idx_tp_task_id' });
    await queryInterface.addIndex('task_prerequisites', { fields: ['prerequisite_task_id'], name: 'idx_tp_prerequisite_task_id' });
  },

  async down(queryInterface) {
    await queryInterface.dropTable('task_prerequisites');
  },
};