'use strict';

// course_id is nullable — the junction revamp (20260707000001) allows
// standalone (course-less) unit reads.
module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('unit_reading_progress', {
      progress_id:      { type: Sequelize.UUID, defaultValue: Sequelize.UUIDV4, primaryKey: true },
      user_id:          { type: Sequelize.BIGINT, allowNull: false, references: { model: 'users',   key: 'user_id'   }, onDelete: 'CASCADE' },
      course_id:        { type: Sequelize.BIGINT, allowNull: true,  references: { model: 'courses', key: 'course_id' }, onDelete: 'CASCADE' },
      unit_id:          { type: Sequelize.BIGINT, allowNull: false, references: { model: 'units',   key: 'unit_id'   }, onDelete: 'CASCADE' },
      status:           { type: Sequelize.ENUM('in_progress', 'completed'), allowNull: false, defaultValue: 'in_progress' },
      completed_at:     { type: Sequelize.DATE, allowNull: true },
      last_accessed_at: { type: Sequelize.DATE, allowNull: false, defaultValue: Sequelize.literal('CURRENT_TIMESTAMP') },
      createdBy:        { type: Sequelize.BIGINT, allowNull: true },
      updatedBy:        { type: Sequelize.BIGINT, allowNull: true },
      createdAt:        { type: Sequelize.DATE, allowNull: false },
      updatedAt:        { type: Sequelize.DATE, allowNull: false },
    });

    await queryInterface.addIndex('unit_reading_progress', {
      fields: ['user_id', 'unit_id'],
      unique: true,
      name:   'uq_urp_user_unit',
    });

    await queryInterface.addIndex('unit_reading_progress', { fields: ['user_id'],   name: 'idx_urp_user_id'   });
    await queryInterface.addIndex('unit_reading_progress', { fields: ['course_id'], name: 'idx_urp_course_id' });
    await queryInterface.addIndex('unit_reading_progress', { fields: ['unit_id'],   name: 'idx_urp_unit_id'   });
    await queryInterface.addIndex('unit_reading_progress', { fields: ['status'],    name: 'idx_urp_status'    });
  },

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