Advanced Discount Code: Create and Configure Discount Code Campaign

User story: As a merchant, I want to create an Advanced Discount Code campaign so that I can issue a single discount code that applies one or more discount types (product, order, shipping) to increase conversions and manage promotions centrally.

Acceptance criteria / requirements:

• UI: Provide a Create Campaign flow requiring: Campaign name, Discount code, and at least one enabled discount module. Validation errors shown when required fields are missing.

• Product Discount module support:

• Allow selecting scope (products or variants) and specifying percentage or fixed discount.

• Support no-requirement application (applies whenever code entered for scoped items).

• Support minimum quantity requirement (only apply when required item quantity met).

• Support exclusions list (apply to selected items except excluded SKUs).

• Order Discount module support:

• Allow percentage or fixed discount applied to order subtotal.

• Support no requirements (applies to entire order subtotal when code used).

• Support minimum purchase amount threshold.

• Support minimum item quantity threshold.

• Shipping Discount module support:

• Support percentage off shipping or full free shipping.

• Support no requirements (applies to shipping when code used).

• Support minimum purchase amount threshold and minimum quantity threshold for shipping discount.

• Multi-module campaigns:

• Allow enabling any combination of Product, Order, and Shipping modules in a single campaign.

• Evaluate each module independently and apply according to defined combination rules.

• Combination rules (stacking):

• Ability to configure stacking behavior: No combinations allowed, Partial combinations allowed (select categories), or Full combinations allowed.

• Scheduling:

• Support immediate activation if no schedule defined.

• Support start date scheduling and start+end window scheduling.

• Other behaviors:

• Campaign preview before activation (including mobile preview) and ability to activate/reactivate a deactivated campaign.

• Clear messaging when a campaign is inactive and guidance to reactivate.

• Persist the generated campaign and apply discount logic at checkout according to the scenarios described.

Notes: All behaviors described are supported by the current Advanced Discount Code model (Campaign -> Discount Code -> optional Product/Order/Shipping modules -> Combination Rules -> Schedule). Implement UI flows and validations to surface these configuration options and to help merchants create, preview, activate, and reactivate discount code campaigns.