WIP add cart calculation functions

src/pages/dashboard/Content/Tariffs/cartCalcs.ts

@@ -0,0 +1,163 @@
+import { Cart } from "../../../../model/cart";
+import { Tariffs } from "../../../../model/tariff";
+import { User } from "../../../../model/user";
+
+
+export function calcCartData(
+    user: User,
+    cartItems: Cart.CartItem[],
+    discounts: Cart.AnyDiscount[],
+    privileges: Cart.Privilege[],
+    promocode?: Cart.Promocode,
+): Cart.CartTotal {
+    const cartTotal: Cart.CartTotal = {
+        items: [],
+        totalPrice: 0,
+        priceByService: {
+            templategen: 0,
+            squiz: 0,
+            dwarfener: 0,
+        },
+    };
+
+    for (const discount of discounts) {
+        if (discount.conditionType !== "userType" || discount.condition.userType !== user.Type) continue;
+
+        cartItems.forEach(cartItem => {
+            cartTotal.items.push({
+                envolvedDiscounts: [],
+                item: cartItem.item,
+                totalPrice: cartItem.price,
+            });
+            cartTotal.totalPrice += cartItem.price;
+        });
+
+        return cartTotal;
+    }
+
+    if (promocode) {
+        for (const discount of discounts) {
+            if (discount.conditionType !== "user" || discount.condition.user !== user.ID || discount.condition.coupon !== promocode.name) continue;
+
+            for (const cartItem of cartItems) {
+                const cartItemTotal = calcCartItemWithPromocode(cartItem, discount, cartTotal.priceByService);
+
+                cartTotal.items.push(cartItemTotal);
+                cartTotal.totalPrice += cartItemTotal.totalPrice;
+            }
+
+            return cartTotal;
+        }
+    }
+
+    for (const cartItem of cartItems) {
+        const cartItemTotal: Cart.CartItemTotal = {
+            item: cartItem.item,
+            envolvedDiscounts: [],
+            totalPrice: cartItem.price,
+        };
+
+        if (isPackage(cartItem.item)) {
+            // TODO implement for package
+
+            throw new Error("unimplemented");
+        }
+
+        const tariff = cartItem.item;
+
+        const discountsForTariffService = discounts.filter((discount): discount is Cart.ServiceDiscount => (
+            discount.conditionType === "service" && discount.condition.service.id === tariff.service
+        ));
+        const maxValueServiceDiscount = discountsForTariffService.reduce((prev, current) => {
+            return current.condition.service.value > prev.condition.service.value ? current : prev;
+        });
+
+        cartItemTotal.totalPrice *= maxValueServiceDiscount.target.factor;
+        cartItemTotal.envolvedDiscounts.push(maxValueServiceDiscount._id);
+
+
+        const maxPrivilegeDiscount = findMaxApplicablePrivilegeDiscount(tariff, discounts);
+        if (maxPrivilegeDiscount) {
+            maxPrivilegeDiscount.target.products.forEach(product => {
+                if (product.productId === tariff.id) { // TODO productId - ид продукта(тариф или пакет тарифов) или привилегии? Если второе, то откуда берется привилегия?
+                    cartItemTotal.totalPrice *= product.factor;
+                    cartItemTotal.envolvedDiscounts.push(maxPrivilegeDiscount._id);
+                }
+            });
+        }
+
+        cartTotal.items.push(cartItemTotal);
+        cartTotal.totalPrice += cartItemTotal.totalPrice;
+        cartTotal.priceByService[tariff.service] += cartItemTotal.totalPrice;
+    }
+
+    return cartTotal;
+}
+
+function findMaxApplicablePrivilegeDiscount(
+    tariff: Tariffs.Tariff,
+    discounts: Cart.AnyDiscount[],
+): Cart.PrivilegeDiscount | null {
+    const applicablePrivilegeDiscounts = discounts.filter((discount): discount is Cart.PrivilegeDiscount => {
+        return discount.conditionType === "privilege" && tariff.amount >= discount.condition.privilege.value;
+    });
+
+    if (!applicablePrivilegeDiscounts.length) return null;
+
+    const maxValueDiscount = applicablePrivilegeDiscounts.reduce(
+        (prev, current) => current.condition.privilege.value > prev.condition.privilege.value ? current : prev
+    );
+
+    return maxValueDiscount;
+};
+
+function calcCartItemWithPromocode(
+    cartItem: Cart.CartItem,
+    discount: Cart.UserDiscount,
+    priceByService: { [Key in Tariffs.ServiceType]: number; },
+): Cart.CartItemTotal {
+    const cartItemTotal: Cart.CartItemTotal = {
+        item: cartItem.item,
+        envolvedDiscounts: [],
+        totalPrice: 0,
+    };
+
+    if (isPackage(cartItem.item)) {
+        // TODO implement for package
+
+        throw new Error("unimplemented");
+    }
+
+    const tariff = cartItem.item;
+
+    discount.target.products.forEach(product => {
+        if (product.productId === tariff.id) { // TODO productId - ид продукта(тариф или пакет тарифов) или привилегии? Если второе, то откуда берется привилегия?
+            cartItemTotal.totalPrice *= product.factor;
+            cartItemTotal.envolvedDiscounts.push(discount._id);
+        }
+    });
+
+    priceByService[tariff.service] = cartItemTotal.totalPrice;
+
+    return cartItemTotal;
+}
+
+export function packTariffs(tariffs: Tariffs.Tariff[]): Tariffs.Package {
+    const id = Date.now().toString(); // TODO actual id
+    const name = "Package"; // TODO actual name
+    const services: Tariffs.ServiceType[] = [];
+    tariffs.forEach(tariff => {
+        if (!services.includes(tariff.service)) services.push(tariff.service);
+    });
+
+    return {
+        id,
+        name,
+        services,
+        tariffs,
+    };
+}
+
+export function isPackage(item: Tariffs.Tariff | Tariffs.Package): item is Tariffs.Package {
+    return "tariffs" in item;
+}