feat: add global charges and discounts

Author: vaened

src/Carts/SnapshotCart.php

@@ -7,6 +7,7 @@
 
 namespace Vaened\SwiftCart\Carts;
 
+use Vaened\PriceEngine\AdjustmentManager;
 use Vaened\SwiftCart\Entities\Identifiable;
 use Vaened\SwiftCart\Entities\TradedCommercialTransaction;
 use Vaened\SwiftCart\Items\ImmutableCartItem;
@@ -18,12 +19,18 @@ final class SnapshotCart extends SwiftCart
 {
     private readonly ImmutableCartItems $immutables;
 
-    private ImmutableCartItems          $items;
+    private readonly ImmutableCartItems $items;
+
+    private readonly AdjustmentManager  $charges;
+
+    private readonly AdjustmentManager  $discounts;
 
     public function __construct(TradedCommercialTransaction $transaction)
     {
         $this->immutables = $transaction->items()->toImmutables();
         $this->items      = new ImmutableCartItems([]);
+        $this->charges    = $this->createManagerOf($transaction->charges());
+        $this->discounts  = $this->createManagerOf($transaction->discounts());
     }
 
     public function locate(Identifiable $identifiable): ?ImmutableCartItem
@@ -57,6 +64,16 @@ protected function staging(): ImmutableCartItems
         return $this->items;
     }
 
+    protected function globalChargesManager(): AdjustmentManager
+    {
+        return $this->charges;
+    }
+
+    protected function globalDiscountsManager(): AdjustmentManager
+    {
+        return $this->discounts;
+    }
+
     private function ensureValidItem(?ImmutableCartItem $item): void
     {
         if (null === $item) {

src/Carts/SwiftCart.php

@@ -7,22 +7,41 @@
 
 namespace Vaened\SwiftCart\Carts;
 
+use Vaened\PriceEngine\AdjustmentManager;
+use Vaened\PriceEngine\Adjustments;
+use Vaened\PriceEngine\Adjustments\Adjusters;
 use Vaened\Support\Types\ArrayList;
 use Vaened\SwiftCart\Entities\Identifiable;
-use Vaened\SwiftCart\Items\CartItem;
-use Vaened\SwiftCart\Items\CartItems;
+use Vaened\SwiftCart\Items\{CartItem, CartItems};
 use Vaened\SwiftCart\Summary;
 use Vaened\SwiftCart\Totalizer;
 
 abstract class SwiftCart
 {
-    abstract public function summary(): Summary;
+    abstract public function locate(Identifiable $identifiable): ?CartItem;
 
     abstract protected function staging(): CartItems;
 
-    public function locate(Identifiable $identifiable): ?CartItem
+    abstract protected function globalChargesManager(): AdjustmentManager;
+
+    abstract protected function globalDiscountsManager(): AdjustmentManager;
+
+    public function globalCharges(): Adjustments
+    {
+        return $this->syncAdjustments($this->globalChargesManager());
+    }
+
+    public function globalDiscounts(): Adjustments
     {
-        return $this->staging()->locate($identifiable);
+        return $this->syncAdjustments($this->globalDiscountsManager());
+    }
+
+    public function summary(): Summary
+    {
+        return $this->totalizer()->summary(
+            additionalCharges  : $this->globalCharges()->total(),
+            additionalDiscounts: $this->globalDiscounts()->total(),
+        );
     }
 
     public function has(Identifiable $identifiable): bool
@@ -42,8 +61,19 @@ public function items(): ArrayList
         );
     }
 
+    protected function createManagerOf(Adjusters $adjusters): AdjustmentManager
+    {
+        return new AdjustmentManager($adjusters, $this->totalizer()->total(), quantity: 1);
+    }
+
     protected function totalizer(): Totalizer
     {
         return $this->staging()->totalizer();
     }
+
+    private function syncAdjustments(AdjustmentManager $manager): Adjustments
+    {
+        $manager->revalue($this->totalizer()->total());
+        return $manager->adjustments();
+    }
 }

src/Entities/TradedCommercialTransaction.php

@@ -7,7 +7,7 @@
 
 namespace Vaened\SwiftCart\Entities;
 
-interface TradedCommercialTransaction
+interface TradedCommercialTransaction extends Discountable, Chargeable
 {
     public function items(): TradedCommercialTransactionItems;
 }

tests/Utils/Billing/Invoice.php

@@ -7,26 +7,60 @@
 
 namespace Vaened\SwiftCart\Tests\Utils\Billing;
 
+use Vaened\PriceEngine\Adjustments\Adjusters;
+use Vaened\PriceEngine\Adjustments\Charge;
+use Vaened\PriceEngine\Adjustments\Discount;
 use Vaened\SwiftCart\Entities\TradedCommercialTransaction;
 use Vaened\SwiftCart\Entities\TradedCommercialTransactionItems;
 
+use function Lambdish\Phunctional\each;
+
 final class Invoice implements TradedCommercialTransaction
 {
+    private readonly Adjusters $charges;
+
+    private readonly Adjusters $discounts;
+
     public function __construct(
         private readonly InvoiceDetailItems $items,
     )
     {
+        $this->charges   = Adjusters::empty();
+        $this->discounts = Adjusters::empty();
     }
 
     public static function create(InvoiceDetailItems $items): self
     {
         return new self($items);
     }
 
+    public function with(Discount|Charge ...$adjusters): self
+    {
+        each(function (Discount|Charge $adjuster) {
+            if ($adjuster instanceof Discount) {
+                $this->discounts->push($adjuster);
+            } else {
+                $this->charges->push($adjuster);
+            }
+        }, $adjusters);
+
+        return $this;
+    }
+
     public function items(): TradedCommercialTransactionItems
     {
         return new TradedCommercialTransactionItems(
             $this->items->values()
         );
     }
+
+    public function charges(): Adjusters
+    {
+        return $this->charges;
+    }
+
+    public function discounts(): Adjusters
+    {
+        return $this->discounts;
+    }
 }