feat: implement min/max discount logic for pricing rules and promotional schemes

POS/src/stores/posCart.js

@@ -953,9 +953,11 @@ export const usePOSCartStore = defineStore("posCart", () => {
 					);
 				} else if (offer.apply_on === "Item Group") {
 					const eligibleGroups = offer.eligible_item_groups || [];
-					eligibleItems = invoiceItems.value.filter((item) =>
-						eligibleGroups.includes(item.item_group)
-					);
+					eligibleItems = eligibleGroups.includes("All Item Groups")
+						? invoiceItems.value
+						: invoiceItems.value.filter((item) =>
+								eligibleGroups.includes(item.item_group)
+							);
 				} else if (offer.apply_on === "Brand") {
 					const eligibleBrands = offer.eligible_brands || [];
 					eligibleItems = invoiceItems.value.filter((item) =>

POS/src/stores/posOffers.js

@@ -181,6 +181,9 @@ export const usePOSOffersStore = defineStore("posOffers", () => {
 		} else if (offer?.apply_on === "Item Group") {
 			const eligibleGroups = offer.eligible_item_groups || [];
 			if (eligibleGroups.length > 0) {
+				if (eligibleGroups.includes("All Item Groups")) {
+					return cartSnapshot.value.itemCount || 0;
+				}
 				// Sum quantities of all items in eligible groups
 				return eligibleGroups.reduce((sum, group) => {
 					return sum + (itemGroupQuantities[group] || 0);
@@ -259,9 +262,9 @@ export const usePOSOffersStore = defineStore("posOffers", () => {
 		} else if (offer?.apply_on === "Item Group") {
 			const eligibleGroups = offer.eligible_item_groups || [];
 			if (eligibleGroups.length > 0) {
-				const hasEligibleGroup = eligibleGroups.some((group) =>
-					cartItemGroups.includes(group)
-				);
+				const hasEligibleGroup =
+					eligibleGroups.includes("All Item Groups") ||
+					eligibleGroups.some((group) => cartItemGroups.includes(group));
 				if (!hasEligibleGroup) {
 					return {
 						eligible: false,

pos_next/__init__.py

@@ -25,6 +25,30 @@ def console(*data):
 except Exception:
 	pass
 
+
+try:
+	from erpnext.accounts.doctype.pricing_rule import pricing_rule as _erpnext_pricing_rule
+
+	from pos_next.overrides.pricing_rule import (
+		apply_price_discount_rule as _pos_next_apply_price_discount_rule,
+	)
+
+	_erpnext_pricing_rule.apply_price_discount_rule = _pos_next_apply_price_discount_rule
+except Exception:
+	if frappe:
+		frappe.log_error(frappe.get_traceback(), "Pricing Rule Override Error")
+
+
+try:
+	from erpnext.accounts.doctype.promotional_scheme import promotional_scheme as _promotional_scheme
+
+	for _min_max_field in ("apply_discount_on_price", "min_or_max_discount_qty_limit"):
+		if _min_max_field not in _promotional_scheme.price_discount_fields:
+			_promotional_scheme.price_discount_fields.append(_min_max_field)
+except Exception:
+	if frappe:
+		frappe.log_error(frappe.get_traceback(), "Promotional Scheme Field Patch Error")
+
 # Frappe/ERPNext compatibility shim:
 # ERPNext may pass do_not_round_fields to round_floats_in, but older Frappe
 # versions don't accept that kwarg.

pos_next/api/invoices.py

@@ -43,10 +43,12 @@
 	from erpnext.accounts.doctype.pricing_rule.utils import (
 		get_applied_pricing_rules as erpnext_get_applied_pricing_rules,
 	)
+	from pos_next.overrides.pricing_rule import apply_min_max_price_discounts
 except Exception:  # pragma: no cover - ERPNext not installed in some environments
 	erpnext_apply_pricing_rule = None
 	erpnext_get_applied_pricing_rules = None
 	erpnext_apply_pricing_rule_on_transaction = None
+	apply_min_max_price_discounts = None
 
 
 # ==========================================
@@ -3205,6 +3207,12 @@ def apply_offers(invoice_data, selected_offers=None):
 					# Fetch full pricing rule to get discount values
 					full_rule = frappe.get_cached_doc("Pricing Rule", rule_name)
 
+					# Min/Max rules are deferred to apply_min_max_price_discounts
+					# (cross-item ranking). Applying them here would discount every
+					# matching item, defeating the "cheapest/most-expensive" logic.
+					if full_rule.get("apply_discount_on_price") in ("Min", "Max"):
+						continue
+
 					if full_rule.rate_or_discount == "Discount Percentage" and full_rule.discount_percentage:
 						discount_percentage += flt(full_rule.discount_percentage)
 					elif full_rule.rate_or_discount == "Discount Amount" and full_rule.discount_amount:
@@ -3272,6 +3280,33 @@ def apply_offers(invoice_data, selected_offers=None):
 			free_items_map.setdefault(key, free_item_doc)
 		applied_rules.update(txn_result.get("applied_rules", set()))
 
+		# Apply Min/Max ("cheapest/most-expensive item") price rules. These were
+		# deferred by the per-item engine (see pos_next.overrides.pricing_rule) and
+		# need a cross-item ranking pass over the whole cart. The mock doc has no
+		# calculate_taxes_and_totals(); the post-processor materialises rate/amount
+		# on each discounted item directly.
+		if apply_min_max_price_discounts:
+			mock_doc = frappe._dict(
+				{
+					"doctype": invoice.get("doctype") or "Sales Invoice",
+					"items": prepared_items,
+					"selling_price_list": pricing_args.price_list,
+					"company": pricing_args.company,
+					"customer": pricing_args.customer,
+				}
+			)
+			min_max_allowed = set(rule_map) if selected_offer_names else None
+			apply_min_max_price_discounts(mock_doc, allowed_rules=min_max_allowed)
+
+		# Surface Min/Max rules in the response so the frontend tracks them as applied.
+		if erpnext_get_applied_pricing_rules:
+			for prepared_item in prepared_items:
+				if not prepared_item.get("pricing_rules"):
+					continue
+				for pr_name in erpnext_get_applied_pricing_rules(prepared_item.get("pricing_rules")):
+					if pr_name in rule_map:
+						applied_rules.add(pr_name)
+
 		return {
 			"items": [dict(item) for item in prepared_items],
 			"free_items": [dict(item) for item in free_items_map.values()],

pos_next/api/offers.py

@@ -13,7 +13,7 @@
 
 import frappe
 from frappe import _
-from frappe.utils import flt, getdate, nowdate
+from frappe.utils import cint, flt, getdate, nowdate
 
 # ============================================================================
 # Constants
@@ -76,6 +76,8 @@ class Offer:
 	rate: float
 	discount_amount: float
 	discount_percentage: float
+	apply_discount_on_price: str | None
+	min_or_max_discount_qty_limit: int
 	valid_from: str | None
 	valid_upto: str | None
 	source: str
@@ -242,6 +244,7 @@ def fetch_price_slabs(scheme_names: list[str]) -> dict[str, dict]:
 			SELECT
 				parent, min_qty, max_qty, min_amount, max_amount,
 				rate_or_discount, rate, discount_amount, discount_percentage,
+				apply_discount_on_price, min_or_max_discount_qty_limit,
 				apply_multiple_pricing_rules
 			FROM `tabPromotional Scheme Price Discount`
 			WHERE parent IN %s AND disable = 0
@@ -338,6 +341,10 @@ def build_from_scheme_rule(rule: dict, slab: dict, eligibility: OfferEligibility
 			rate=flt(slab.get("rate", 0)) if is_price_discount else 0,
 			discount_amount=flt(slab.get("discount_amount", 0)) if is_price_discount else 0,
 			discount_percentage=flt(slab.get("discount_percentage", 0)) if is_price_discount else 0,
+			apply_discount_on_price=(slab.get("apply_discount_on_price") if is_price_discount else None),
+			min_or_max_discount_qty_limit=(
+				cint(slab.get("min_or_max_discount_qty_limit", 0)) if is_price_discount else 0
+			),
 			valid_from=rule.get("valid_from"),
 			valid_upto=rule.get("valid_upto"),
 			source=OfferSource.PROMOTIONAL_SCHEME,
@@ -392,6 +399,8 @@ def build_from_standalone_rule(rule: dict, eligibility: OfferEligibility) -> Off
 			rate=flt(rule.get("rate", 0)),
 			discount_amount=flt(rule.get("discount_amount", 0)),
 			discount_percentage=flt(rule.get("discount_percentage", 0)),
+			apply_discount_on_price=rule.get("apply_discount_on_price"),
+			min_or_max_discount_qty_limit=cint(rule.get("min_or_max_discount_qty_limit", 0)),
 			valid_from=rule.get("valid_from"),
 			valid_upto=rule.get("valid_upto"),
 			source=OfferSource.PRICING_RULE,
@@ -530,6 +539,7 @@ def _get_standalone_pricing_rule_offers(company: str, date: str) -> list[Offer]:
 			name, title, apply_on, selling,
 			coupon_code_based, one_time_per_customer, price_or_product_discount,
 			rate_or_discount, rate, discount_amount, discount_percentage,
+			apply_discount_on_price, min_or_max_discount_qty_limit,
 			min_qty, max_qty, min_amt, max_amt,
 			priority, valid_from, valid_upto
 		FROM `tabPricing Rule`

pos_next/hooks.py

@@ -48,7 +48,11 @@
 # page_js = {"page" : "public/js/file.js"}
 
 # include js in doctype views
-doctype_js = {"Customer": "public/js/customer.js"}
+doctype_js = {
+	"Customer": "public/js/customer.js",
+	"Pricing Rule": "public/js/pricing_rule.js",
+	"Promotional Scheme": "public/js/promotional_scheme.js",
+}
 # doctype_list_js = {"doctype" : "public/js/doctype_list.js"}
 # doctype_tree_js = {"doctype" : "public/js/doctype_tree.js"}
 # doctype_calendar_js = {"doctype" : "public/js/doctype_calendar.js"}
@@ -151,6 +155,7 @@
 		"validate": [
 			"pos_next.api.sales_invoice_hooks.validate",
 			"pos_next.api.wallet.validate_wallet_payment",
+			"pos_next.overrides.pricing_rule.apply_min_max_price_discounts",
 		],
 		"before_cancel": "pos_next.api.sales_invoice_hooks.before_cancel",
 		"on_submit": [
@@ -165,7 +170,15 @@
 		"after_insert": "pos_next.realtime_events.emit_invoice_created_event",
 	},
 	"POS Profile": {"on_update": "pos_next.realtime_events.emit_pos_profile_updated_event"},
-	"Promotional Scheme": {"on_update": "pos_next.overrides.pricing_rule.sync_pos_only_to_pricing_rules"},
+	"Promotional Scheme": {
+		"validate": "pos_next.overrides.pricing_rule.enforce_min_max_pricing_config",
+		"on_update": "pos_next.overrides.pricing_rule.sync_pos_only_to_pricing_rules",
+	},
+	"Pricing Rule": {"validate": "pos_next.overrides.pricing_rule.enforce_min_max_pricing_config"},
+	"Sales Order": {"validate": "pos_next.overrides.pricing_rule.apply_min_max_price_discounts"},
+	"Quotation": {"validate": "pos_next.overrides.pricing_rule.apply_min_max_price_discounts"},
+	"Delivery Note": {"validate": "pos_next.overrides.pricing_rule.apply_min_max_price_discounts"},
+	"POS Invoice": {"validate": "pos_next.overrides.pricing_rule.apply_min_max_price_discounts"},
 }
 
 # Scheduled Tasks