refactor: improve sumaries

Author: vaened

src/Carts/SnapshotCart.php

@@ -12,6 +12,7 @@
 use Vaened\SwiftCart\Items\ImmutableCartItem;
 use Vaened\SwiftCart\Items\ImmutableCartItems;
 use Vaened\SwiftCart\NotFoundItem;
+use Vaened\SwiftCart\Summary;
 
 final class SnapshotCart extends SwiftCart
 {
@@ -46,6 +47,11 @@ public function pullAll(): void
         $this->staging()->combine($immutables);
     }
 
+    public function summary(): Summary
+    {
+        return $this->totalizer()->summary();
+    }
+
     protected function staging(): ImmutableCartItems
     {
         return $this->items;

src/Carts/SwiftCart.php

@@ -12,15 +12,13 @@
 use Vaened\SwiftCart\Items\CartItem;
 use Vaened\SwiftCart\Items\CartItems;
 use Vaened\SwiftCart\Summary;
+use Vaened\SwiftCart\Totalizer;
 
 abstract class SwiftCart
 {
-    abstract protected function staging(): CartItems;
+    abstract public function summary(): Summary;
 
-    public function summary(): Summary
-    {
-        return $this->staging()->summary();
-    }
+    abstract protected function staging(): CartItems;
 
     public function locate(Identifiable $identifiable): ?CartItem
     {
@@ -43,4 +41,9 @@ public function items(): ArrayList
             $this->staging()->items()
         );
     }
+
+    protected function totalizer(): Totalizer
+    {
+        return $this->staging()->totalizer();
+    }
 }

src/Items/CartItems.php

@@ -11,8 +11,7 @@
 use Vaened\Support\Types\InvalidType;
 use Vaened\SwiftCart\AlreadyAttachedItem;
 use Vaened\SwiftCart\Entities\Identifiable;
-use Vaened\SwiftCart\Summary;
-use Vaened\SwiftCart\TotalSummaries;
+use Vaened\SwiftCart\Totalizer;
 
 use function array_map;
 use function Lambdish\Phunctional\each;
@@ -34,13 +33,6 @@ public function ids(): array
         return $this->map(static fn(CartItem $item) => $item->uniqueId());
     }
 
-    public function summary(): Summary
-    {
-        return TotalSummaries::of(
-            $this->map($this->summaries())
-        )->summary();
-    }
-
     public function has(Identifiable $identifiable): bool
     {
         return isset($this->items[$identifiable->uniqueId()]);
@@ -59,6 +51,13 @@ public function map(callable $callback): array
         return array_map($callback, $this->items);
     }
 
+    public function totalizer(): Totalizer
+    {
+        return Totalizer::of(
+            $this->map($this->summaries())
+        );
+    }
+
     protected function attach(CartItem $item): void
     {
         $this->ensureNotAddedBefore($item);

src/TotalSummaries.php renamed to src/Totalizer.php

@@ -11,62 +11,66 @@
 use Vaened\PriceEngine\TotalSummary;
 use Vaened\Support\Types\ArrayObject;
 
-final class TotalSummaries extends ArrayObject
+final class Totalizer extends ArrayObject
 {
     public static function of(array $summaries): self
     {
         return new self($summaries);
     }
 
-    public function subtotal(): Money
+    public function summary(Money $additionalCharges = null, Money $additionalDiscounts = null): Summary
     {
-        return $this->sum(
-            static fn(TotalSummary $summary) => $summary->subtotal()
+        $subtotal = $this->subtotal();
+
+        return new Summary(
+            subtotal      : $subtotal,
+            totalTaxes    : $this->totalTaxes(),
+            totalCharges  : $this->totalCharges()
+                                 ->plus(null === $additionalCharges ? 0 : $additionalCharges),
+            totalDiscounts: $this->totalDiscounts()
+                                 ->plus(null === $additionalDiscounts ? 0 : $additionalDiscounts),
+            total         : $this->total(),
         );
     }
 
-    public function totalTaxes(): Money
+    public function total(): Money
     {
         return $this->sum(
-            static fn(TotalSummary $summary) => $summary->taxes()->total()
+            static fn(TotalSummary $summary) => $summary->total()
         );
     }
 
-    public function totalCharges(): Money
+    protected function type(): string
     {
-        return $this->sum(
-            static fn(TotalSummary $summary) => $summary->charges()->total()
-        );
+        return TotalSummary::class;
     }
 
-    public function totalDiscounts(): Money
+    private function subtotal(): Money
     {
         return $this->sum(
-            static fn(TotalSummary $summary) => $summary->discounts()->total()
+            static fn(TotalSummary $summary) => $summary->subtotal()->gross()
         );
     }
 
-    public function total(): Money
+    private function totalTaxes(): Money
     {
         return $this->sum(
-            static fn(TotalSummary $summary) => $summary->total()
+            static fn(TotalSummary $summary) => $summary->taxes()->total()
         );
     }
 
-    public function summary(): Summary
+    private function totalCharges(): Money
     {
-        return new Summary(
-            subtotal      : $this->subtotal(),
-            totalTaxes    : $this->totalTaxes(),
-            totalCharges  : $this->totalCharges(),
-            totalDiscounts: $this->totalDiscounts(),
-            total         : $this->total(),
+        return $this->sum(
+            static fn(TotalSummary $summary) => $summary->charges()->total()
         );
     }
 
-    protected function type(): string
+    private function totalDiscounts(): Money
     {
-        return TotalSummary::class;
+        return $this->sum(
+            static fn(TotalSummary $summary) => $summary->discounts()->total()
+        );
     }
 
     private function sum(callable $callback): Money