feat(ADM-018): completed feature

project/migrations/014_promotions.js

@@ -0,0 +1,31 @@
+/** Promotions and selected cart promo code. */
+
+/** @param {import('node-pg-migrate').MigrationBuilder} pgm */
+export const up = (pgm) => {
+  pgm.sql(`
+    CREATE TABLE promotions_promotions (
+      code text PRIMARY KEY,
+      type text NOT NULL,
+      value integer NOT NULL,
+      starts_at timestamptz NOT NULL,
+      ends_at timestamptz NOT NULL,
+      usage_limit integer,
+      usage_count integer NOT NULL DEFAULT 0,
+      active boolean NOT NULL DEFAULT true,
+      created_at timestamptz NOT NULL DEFAULT now(),
+      updated_at timestamptz NOT NULL DEFAULT now(),
+      CONSTRAINT promotions_type_check CHECK (type IN ('percent', 'fixed_amount')),
+      CONSTRAINT promotions_value_positive CHECK (value > 0),
+      CONSTRAINT promotions_usage_limit_positive CHECK (usage_limit IS NULL OR usage_limit > 0),
+      CONSTRAINT promotions_usage_count_non_negative CHECK (usage_count >= 0),
+      CONSTRAINT promotions_window_check CHECK (ends_at > starts_at)
+    )
+  `);
+  pgm.sql('ALTER TABLE cart_carts ADD COLUMN promo_code text');
+};
+
+/** @param {import('node-pg-migrate').MigrationBuilder} pgm */
+export const down = (pgm) => {
+  pgm.sql('ALTER TABLE cart_carts DROP COLUMN IF EXISTS promo_code');
+  pgm.sql('DROP TABLE IF EXISTS promotions_promotions');
+};