'use strict';

// started_at/last_saved_at/createdAt/updatedAt are TIMESTAMP WITHOUT TIME
// ZONE live (unlike most other tables' TIMESTAMPTZ columns), so raw type
// strings are used instead of Sequelize.DATE to match exactly.
module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('quiz_sessions', {
      session_id:    { type: Sequelize.BIGINT, primaryKey: true, autoIncrement: true },
      uuid:          { type: Sequelize.UUID, allowNull: false, unique: true, defaultValue: Sequelize.literal('gen_random_uuid()') },
      user_id:       { type: Sequelize.BIGINT, allowNull: false, references: { model: 'users', key: 'user_id' }, onDelete: 'CASCADE' },
      quiz_id:       { type: Sequelize.BIGINT, allowNull: false, references: { model: 'unit_quizzes', key: 'quiz_id' }, onDelete: 'CASCADE' },
      course_id:     { type: Sequelize.BIGINT, allowNull: true },
      unit_id:       { type: Sequelize.BIGINT, allowNull: true },
      status:        { type: Sequelize.STRING(20), allowNull: false, defaultValue: 'in_progress' },
      draft_answers: { type: Sequelize.JSONB, allowNull: true },
      started_at:    { type: 'TIMESTAMP', allowNull: false, defaultValue: Sequelize.NOW },
      last_saved_at: { type: 'TIMESTAMP', allowNull: true },
      createdAt:     { type: 'TIMESTAMP', allowNull: false, defaultValue: Sequelize.NOW },
      updatedAt:     { type: 'TIMESTAMP', allowNull: false, defaultValue: Sequelize.NOW },
    });

    await queryInterface.addIndex('quiz_sessions', ['quiz_id'], { name: 'idx_qs_quiz_id' });
    await queryInterface.addIndex('quiz_sessions', ['status'], { name: 'idx_qs_status' });
    await queryInterface.addIndex('quiz_sessions', ['user_id'], { name: 'idx_qs_user_id' });
  },

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