Feature/ecommerce template coupons

packages/plugin-ecommerce/src/carts/beforeChange.ts

@@ -1,18 +1,24 @@
 import type { CollectionBeforeChangeHook } from 'payload'
 
+import { getCouponDiscountValue } from '../utilities/getCouponDiscountValue.js'
+
 type Props = {
+  couponsSlug: string
   productsSlug: string
   variantsSlug: string
 }
 
 export const beforeChangeCart: (args: Props) => CollectionBeforeChangeHook =
-  ({ productsSlug, variantsSlug }) =>
+  ({ couponsSlug, productsSlug, variantsSlug }) =>
   async ({ data, req }) => {
-    // Update subtotal based on items in the cart
+    const payload = req.payload
+
     if (data.items && Array.isArray(data.items)) {
       const priceField = `priceIn${data.currency}`
 
       let subtotal = 0
+      let totalItemsDiscount = 0
+      let totalCartDiscount = 0
 
       for (const item of data.items) {
         if (item.variant) {
@@ -27,7 +33,23 @@ export const beforeChangeCart: (args: Props) => CollectionBeforeChangeHook =
             },
           })
 
-          subtotal += variant[priceField] * item.quantity
+          const itemAmount = variant[priceField] * item.quantity
+          subtotal += itemAmount
+
+          if (Array.isArray(item.discount?.discountLines)) {
+            for (const discountLine of item.discount.discountLines) {
+              const coupon = await payload.findByID({
+                id: discountLine.coupon,
+                collection: couponsSlug,
+              })
+
+              discountLine.amount = discountLine.amount ?? 0
+              discountLine.amount += getCouponDiscountValue(itemAmount, coupon)
+              item.discount.amount += discountLine.amount
+
+              totalItemsDiscount += item.discount.amount
+            }
+          }
         } else {
           const id = typeof item.product === 'object' ? item.product.id : item.product
 
@@ -40,12 +62,49 @@ export const beforeChangeCart: (args: Props) => CollectionBeforeChangeHook =
             },
           })
 
-          subtotal += product[priceField] * item.quantity
+          const itemAmount = product[priceField] * item.quantity
+          subtotal += itemAmount
+
+          if (Array.isArray(item.discount?.discountLines)) {
+            for (const discountLine of item.discount.discountLines) {
+              const coupon = await payload.findByID({
+                id: discountLine.coupon,
+                collection: couponsSlug,
+              })
+
+              discountLine.amount = discountLine.amount ?? 0
+              discountLine.amount += getCouponDiscountValue(itemAmount, coupon)
+              if (!item.discount.total) {
+                item.discount.total = 0
+              }
+              item.discount.total += discountLine.amount
+              totalItemsDiscount += item.discount.total
+            }
+          }
         }
       }
 
+      for (const discountLine of data.discount?.discountLines ?? []) {
+        const coupon = await payload.findByID({
+          id: discountLine.coupon,
+          collection: couponsSlug,
+        })
+
+        discountLine.amount = getCouponDiscountValue(subtotal, coupon)
+        totalCartDiscount += discountLine.amount
+      }
+
       data.subtotal = subtotal
+      data.discount = data.discount ?? {}
+      data.discount.cartAmount = totalCartDiscount
+      data.discount.lineItemsAmount = totalItemsDiscount
+      data.discount.totalAmount = totalCartDiscount + totalItemsDiscount
+      data.total = subtotal + data.discount.totalAmount
     } else {
       data.subtotal = 0
+      data.discount.cartAmount = 0
+      data.discount.lineItemsAmount = 0
+      data.discount.totalAmount = 0
+      data.total = 0
     }
   }

packages/plugin-ecommerce/src/carts/cartsCollection.ts

@@ -8,16 +8,25 @@ import { currencyField } from '../fields/currencyField.js'
 import { beforeChangeCart } from './beforeChange.js'
 
 type Props = {
+  /**
+   * Slug of the coupons collection, defaults to 'coupons'.
+   */
+  couponsSlug?: string
   currenciesConfig?: CurrenciesConfig
   /**
    * Slug of the customers collection, defaults to 'users'.
    */
   customersSlug?: string
+  enableCoupons?: boolean
   /**
    * Enables support for variants in the cart.
    * Defaults to false.
    */
   enableVariants?: boolean
+  /**
+   * Enables support for coupons in the cart.
+   * Defaults to false.
+   */
   overrides?: { fields?: FieldsOverride } & Partial<Omit<CollectionConfig, 'fields'>>
   /**
    * Slug of the products collection, defaults to 'products'.
@@ -31,8 +40,10 @@ type Props = {
 
 export const cartsCollection: (props?: Props) => CollectionConfig = (props) => {
   const {
+    couponsSlug = 'coupons',
     currenciesConfig,
     customersSlug = 'users',
+    enableCoupons = false,
     enableVariants = false,
     overrides,
     productsSlug = 'products',
@@ -82,6 +93,67 @@ export const cartsCollection: (props?: Props) => CollectionConfig = (props) => {
         },
       ],
     },
+
+    ...(enableCoupons && currenciesConfig
+      ? [
+          {
+            name: 'discount',
+            type: 'group',
+            fields: [
+              {
+                name: 'discountLines',
+                type: 'array',
+                fields: [
+                  {
+                    name: 'coupon',
+                    type: 'relationship',
+                    hasMany: false,
+                    label: 'Coupon',
+                    relationTo: couponsSlug,
+                  },
+
+                  amountField({
+                    currenciesConfig,
+                    overrides: {
+                      name: 'amount',
+                      label: ({ t }) =>
+                        // @ts-expect-error - translations are not typed in plugins yet
+                        t('plugin-ecommerce:subtotal'),
+                    },
+                  }),
+                ],
+              },
+
+              amountField({
+                currenciesConfig,
+                overrides: {
+                  name: 'totalAmount',
+                  // @ts-expect-error - translations are not typed in plugins yet
+                  label: ({ t }) => t('plugin-ecommerce:discount.amount'),
+                },
+              }),
+
+              amountField({
+                currenciesConfig,
+                overrides: {
+                  name: 'cartAmount',
+                  // @ts-expect-error - translations are not typed in plugins yet
+                  label: ({ t }) => t('plugin-ecommerce:discount.amount'),
+                },
+              }),
+
+              amountField({
+                currenciesConfig,
+                overrides: {
+                  name: 'lineItemsAmount',
+                  // @ts-expect-error - translations are not typed in plugins yet
+                  label: ({ t }) => t('plugin-ecommerce:discount.amount'),
+                },
+              }),
+            ],
+          } as Field,
+        ]
+      : []),
     ...(currenciesConfig
       ? [
           currencyField({
@@ -96,9 +168,20 @@ export const cartsCollection: (props?: Props) => CollectionConfig = (props) => {
                 t('plugin-ecommerce:subtotal'),
             },
           }),
+          amountField({
+            currenciesConfig,
+            overrides: {
+              name: 'total',
+              label: ({ t }) =>
+                // @ts-expect-error - translations are not typed in plugins yet
+                t('plugin-ecommerce:total'),
+            },
+          }),
         ]
       : []),
     cartItemsField({
+      currenciesConfig,
+      enableCoupons,
       enableVariants,
       overrides: {
         label: ({ t }) =>
@@ -135,7 +218,7 @@ export const cartsCollection: (props?: Props) => CollectionConfig = (props) => {
     hooks: {
       beforeChange: [
         // This hook can be used to update the subtotal before saving the cart
-        beforeChangeCart({ productsSlug, variantsSlug }),
+        beforeChangeCart({ couponsSlug, productsSlug, variantsSlug }),
         ...(overrides?.hooks?.beforeChange || []),
       ],
       ...overrides?.hooks,