Hide Cash on Delivery above a cart total

api_version = "2026-10"

[[extensions]]
name = "Hide Cash on Delivery above a cart total"
handle = "hide-cod-above-total"
type = "function"

  [[extensions.targeting]]
  target = "cart.payment-methods.transform.run"
  input_query = "src/cart_payment_methods_transform_run.graphql"
  export = "cart-payment-methods-transform-run"

  [extensions.build]
  command = ""
  path = "dist/function.wasm"

query CartPaymentMethodsTransformRunInput {
  cart {
    cost {
      totalAmount {
        amount
      }
    }
  }
  paymentMethods {
    id
    name
  }
  paymentCustomization {
    metafield(namespace: "$app", key: "function-configuration") {
      jsonValue
    }
  }
}

// @ts-check

/**
 * @typedef {import("../generated/api").CartPaymentMethodsTransformRunInput} CartPaymentMethodsTransformRunInput
 * @typedef {import("../generated/api").CartPaymentMethodsTransformRunResult} CartPaymentMethodsTransformRunResult
 */

/**
 * Settings stored as JSON in the customization's metafield, so the limit can
 * change without a deploy. Used when the metafield is missing.
 */
const DEFAULT_CONFIG = {
  // Cart total (in the checkout currency) above which the methods are hidden.
  maxAmount: 5000,
  // Matched case-insensitively against the start of the payment method name.
  methodNames: ["Cash on Delivery", "Kapıda Ödeme"],
};

/**
 * Lowercase for matching, with Turkish dotless/dotted i folded to "i", so
 * "KAPIDA ÖDEME" and "Kapıda Ödeme" match the same configured name.
 * @param {string} text
 */
const fold = (text) => text.toLowerCase().replace(/ı/g, "i").replace(/\u0307/g, "");

/** @type {CartPaymentMethodsTransformRunResult} */
const NO_CHANGES = { operations: [] };

/**
 * @param {CartPaymentMethodsTransformRunInput} input
 * @returns {CartPaymentMethodsTransformRunResult}
 */
export function cartPaymentMethodsTransformRun(input) {
  const config = { ...DEFAULT_CONFIG, ...input.paymentCustomization?.metafield?.jsonValue };
  const total = Number(input.cart.cost.totalAmount.amount);
  if (!(total > config.maxAmount)) return NO_CHANGES;

  const names = config.methodNames.map(fold);
  const operations = input.paymentMethods
    .filter((method) => names.some((name) => fold(method.name).startsWith(name)))
    .map((method) => ({ paymentMethodHide: { paymentMethodId: method.id } }));

  return { operations };
}