'use strict';

// Backstop for the stacked-tier model: application code now enforces "at most
// one active row per (user_id, tier)" (see controllers/client/tiers.controller.js
// createOrder/captureOrder and controllers/admin/tiers.controller.js grantTier),
// but a race or a future code path could still violate it. This partial unique
// index makes the DB reject that case outright instead of silently allowing two
// active rows for the same user+tier.
//
// NOT auto-run — this file only defines the migration. Do not execute it against
// the shared dev/prod database without explicit confirmation.
module.exports = {
  async up(queryInterface) {
    await queryInterface.addIndex('user_tiers', ['user_id', 'tier'], {
      unique: true,
      where: { status: 'active' },
      name: 'user_tiers_one_active_per_user_tier',
    });
  },

  async down(queryInterface) {
    await queryInterface.removeIndex('user_tiers', 'user_tiers_one_active_per_user_tier');
  },
};