Init totalization strategy

config/services.yaml

@@ -15,7 +15,9 @@ services:
         App\Gateway\GatewayInterface:
             tags: ['app.gateway.gateway']
         App\Money\Currency\ExchangeInterface:
-            tags: ['app.lib.economy.currency.exchange']
+            tags: ['app.money.currency.exchange']
+        App\Money\Totalization\TotalizerInterface:
+            tags: ['app.money.totalization.totalizer']
         App\Matchfunding\Formula\FormulaInterface:
             tags: ['app.matchfunding.formula']
         App\Matchfunding\Rule\RuleInterface:
@@ -96,7 +98,11 @@ services:
 
     App\Money\Currency\ExchangeLocator:
         arguments:
-            - !tagged 'app.lib.economy.currency.exchange'
+            - !tagged 'app.money.currency.exchange'
+
+    App\Money\Totalization\TotalizerLocator:
+        arguments:
+            - !tagged 'app.money.totalization.totalizer'
 
     App\Mapping\AutoMapper:
         arguments:

src/Money/Totalization/TotalizedMoney.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace App\Money\Totalization;
+
+use App\Money\MoneyInterface;
+
+class TotalizedMoney implements MoneyInterface
+{
+    public function __construct(
+        private int $amount,
+        private string $currency,
+        private int $length,
+    ) {}
+
+    public function getAmount(): int
+    {
+        return $this->amount;
+    }
+
+    public function getCurrency(): string
+    {
+        return $this->currency;
+    }
+
+    /**
+     * @return int the total number of items that were totalized to produce the Money
+     */
+    public function getLength(): int
+    {
+        return $this->length;
+    }
+}

src/Money/Totalization/TotalizerInterface.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace App\Money\Totalization;
+
+interface TotalizerInterface
+{
+    /**
+     * @return string the resource that can be totalized by this Totalizer
+     */
+    public static function getSupportedResource(): string;
+
+    /**
+     * @param array $filters an array of filters to be applied to the resource Collection
+     */
+    public function totalize(array $filters): TotalizedMoney;
+}

src/Money/Totalization/TotalizerLocator.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Money\Totalization;
+
+class TotalizerLocator
+{
+    /** @var array<string, TotalizerInterface> */
+    private array $totalizers;
+
+    public function __construct(
+        iterable $interfaces,
+    ) {
+        /** @var TotalizerInterface[] */
+        $totalizers = \iterator_to_array($interfaces);
+
+        foreach ($totalizers as $totalizer) {
+            $resource = $totalizer::getSupportedResource();
+
+            if (\array_key_exists($resource, $this->totalizers)) {
+                throw new \Exception(\sprintf(
+                    "Duplicated TotalizerInterface. The resource '%s' is already supported by %s",
+                    $resource,
+                    $totalizers[$resource]::class
+                ));
+            }
+
+            $this->totalizers[$resource] = $totalizer;
+        }
+    }
+
+    public function get(string $resource): ?TotalizerInterface
+    {
+        return $this->totalizers[$resource] ?? null;
+    }
+
+    /**
+     * @return array<string, TotalizerInterface>
+     */
+    public function getAll(): array
+    {
+        return $this->totalizers;
+    }
+}