[PN 79] Accumulative Discount

POS/src/components/sale/CouponDialog.vue

@@ -232,13 +232,11 @@
 
 <script setup>
 import { DEFAULT_CURRENCY, formatCurrency as formatCurrencyUtil } from "@/utils/currency";
+import { call } from "@/utils/apiWrapper";
 import { Button, Dialog, Input, createResource } from "frappe-ui";
 import { ref, watch } from "vue";
-import { useInvoice } from "@/composables/useInvoice";
 import { useToast } from "@/composables/useToast";
 
-// Get calculateDiscountAmount helper from composable
-const { calculateDiscountAmount } = useInvoice();
 const { showSuccess, showError, showWarning } = useToast();
 
 const props = defineProps({
@@ -294,18 +292,40 @@ const giftCardsResource = createResource({
 	},
 });
 
-// Resource to validate coupon
-const couponResource = createResource({
-	url: "pos_next.api.offers.validate_coupon",
-	makeParams() {
-		return {
-			coupon_code: couponCode.value,
-			customer: props.customer,
-			company: props.company,
-		};
-	},
-	auto: false,
-});
+// Resource to validate coupon — use call() in applyCoupon for reliable response parsing
+
+function unwrapCouponValidation(raw) {
+	if (!raw) return null;
+	if (raw.valid !== undefined) return raw;
+	if (raw.message?.valid !== undefined) return raw.message;
+	if (typeof raw.message === "object" && raw.message) return raw.message;
+	if (typeof raw.message === "string") return { valid: false, message: raw.message };
+	return raw;
+}
+
+function buildCartItemsSnapshot() {
+	const items = props.items || [];
+	return items.map((item, index) => ({
+		item_code: item.item_code,
+		item_name: item.item_name,
+		brand: item.brand || "",
+		item_group: item.item_group || "",
+		qty: item.quantity || item.qty || 0,
+		quantity: item.quantity || item.qty || 0,
+		rate: item.rate || 0,
+		price_list_rate: item.price_list_rate || item.rate || 0,
+		amount: item.amount || 0,
+		discount_percentage: item.discount_percentage || 0,
+		discount_amount: item.discount_amount || 0,
+		pricing_rules: item.pricing_rules || null,
+		is_free_item: item.is_free_item || 0,
+		is_already_discounted: item.is_already_discounted || 0,
+		discount_source: item.discount_source || "",
+		coupon_code: item.coupon_code || "",
+		idx: index + 1,
+		name: item.name || null,
+	}));
+}
 
 watch(
 	() => props.modelValue,
@@ -347,79 +367,60 @@ function applyGiftCard(card) {
 	applyCoupon();
 }
 
-function getCouponBaseAmount(coupon) {
-	const grandTotal = Number.parseFloat(props.grandTotal || 0);
-	const taxAmount = Number.parseFloat(props.taxAmount || 0);
-	const netTotal = Math.max(grandTotal - taxAmount, 0);
-
-	return coupon.apply_on === "Grand Total" ? grandTotal : netTotal;
-}
-
 async function applyCoupon() {
 	if (!couponCode.value.trim()) {
 		errorMessage.value = __("Please enter a coupon code");
 		return;
 	}
 
+	if (!props.items?.length) {
+		errorMessage.value = __("Add items to the cart before applying a coupon");
+		showWarning(errorMessage.value);
+		return;
+	}
+
 	applying.value = true;
 	errorMessage.value = "";
 
 	try {
-		await couponResource.reload();
-		// Frappe wraps response in { message: {...} }
-		const result = couponResource.data?.message || couponResource.data;
-
-		// Handle if result is the actual response object
-		const validationData =
-			typeof result === "object" && result.valid !== undefined
-				? result
-				: couponResource.data;
+		const result = await call("pos_next.api.offers.validate_coupon", {
+			coupon_code: couponCode.value,
+			customer: props.customer,
+			company: props.company,
+			items: buildCartItemsSnapshot(),
+		});
+		const validationData = unwrapCouponValidation(result);
 
-		if (!validationData || !validationData.valid) {
+		if (!validationData || validationData.valid !== true) {
 			errorMessage.value =
 				validationData?.message || __("The coupon code you entered is not valid");
 			showError(errorMessage.value);
 			return;
 		}
 
 		const coupon = validationData.coupon;
-		const baseAmount = getCouponBaseAmount(coupon);
+		const lineUpdates = validationData.line_updates || [];
+		const totalDiscount = Number.parseFloat(validationData.total_discount || 0);
 
-		// Check minimum amount on the configured coupon base
-		if (coupon.min_amount && baseAmount < coupon.min_amount) {
-			errorMessage.value = __("This coupon requires a minimum purchase of ", [
-				formatCurrency(coupon.min_amount),
-			]);
+		if (!lineUpdates.length || totalDiscount <= 0) {
+			errorMessage.value =
+				validationData?.message || __("No eligible items for this coupon");
 			showWarning(errorMessage.value);
 			return;
 		}
 
-		// Calculate discount on subtotal (before tax) using centralized helper
-		// Transform server coupon format to discount object format
-		const discountObj = {
-			percentage: coupon.discount_type === "Percentage" ? coupon.discount_percentage : 0,
-			amount: coupon.discount_type === "Amount" ? coupon.discount_amount : 0,
-		};
-
-		let discountAmount = calculateDiscountAmount(discountObj, baseAmount);
-
-		// Apply maximum discount limit if specified
-		if (coupon.max_amount && discountAmount > coupon.max_amount) {
-			discountAmount = coupon.max_amount;
-		}
-
-		// Clamp discount to the selected coupon base to prevent negative totals
-		discountAmount = Math.min(discountAmount, baseAmount);
-
 		appliedDiscount.value = {
 			name: coupon.coupon_name || coupon.coupon_code,
-			code: couponCode.value.toUpperCase(),
+			code: (coupon.coupon_code || couponCode.value).toUpperCase(),
 			percentage: coupon.discount_type === "Percentage" ? coupon.discount_percentage : 0,
-			amount: discountAmount,
+			amount: totalDiscount,
 			type: coupon.discount_type,
 			coupon: coupon,
 			apply_on: coupon.apply_on,
-			base_amount: baseAmount,
+			line_updates: lineUpdates,
+			eligible_item_codes: validationData.eligible_item_codes || [],
+			eligible_subtotal: validationData.eligible_subtotal || 0,
+			application_mode: "line",
 		};
 
 		emit("discount-applied", appliedDiscount.value);