'use strict';

module.exports = {
  async up(queryInterface) {
    await queryInterface.sequelize.query(`
      ALTER TABLE community.vocab_srs_item
      ADD COLUMN IF NOT EXISTS is_hard BOOLEAN NOT NULL DEFAULT FALSE;
    `);
    await queryInterface.sequelize.query(`
      CREATE INDEX IF NOT EXISTS idx_vocab_srs_item_hard
      ON community.vocab_srs_item (user_id, course_id, is_hard, next_due_at);
    `);
  },

  async down(queryInterface) {
    await queryInterface.sequelize.query(`
      DROP INDEX IF EXISTS community.idx_vocab_srs_item_hard;
    `);
    await queryInterface.sequelize.query(`
      ALTER TABLE community.vocab_srs_item
      DROP COLUMN IF EXISTS is_hard;
    `);
  }
};