Merge pull request #19 from ShoppinPal/add-version-compare-helper

Add helper method to compare versions returned from the api to already retrieved versions

src/ShoppinPal/Vend/DataObject/Entity/V2/Version.php

@@ -3,6 +3,7 @@
 namespace ShoppinPal\Vend\DataObject\Entity\V2;
 
 use ShoppinPal\Vend\DataObject\Entity\EntityDoAbstract;
+use YapepBase\Exception\ParameterException;
 
 class Version extends EntityDoAbstract
 {
@@ -45,4 +46,36 @@ class Version extends EntityDoAbstract
     public $customers;
 
     public $consignments;
+
+    /**
+     * Returns TRUE if there is a newer version of the given entity.
+     *
+     * Since Vend recently changed this endpoint's behaviour and now returns a version of 1 if the retailer has no
+     * entities for an entity type instead of 0, we will not consider any version less than 10 by default as a new
+     * version (treat it as it has no entities for that type). Since the versions are typically much higher numbers
+     * than 10 this should be safe to be left at 10, but can be overridden by the minimumVersion param.
+     *
+     * @param string   $entityType           The entity type. Must match one of the properties of this entity.
+     * @param int|null $lastRetrievedVersion The last retrieved version
+     * @param int      $minimumVersion       The minimum version number to be considered a new version
+     *
+     * @return bool
+     *
+     * @throws ParameterException If the entity type is invalid
+     */
+    public function hasNewerVersion(string $entityType, ?int $lastRetrievedVersion, int $minimumVersion = 10): bool
+    {
+        $invalidEntityTypes = [
+            'subEntities',
+            'ignoredProperties',
+        ];
+
+        $validEntityTypes = array_diff(array_keys(get_object_vars($this)), $invalidEntityTypes);
+
+        if (!in_array($entityType, $invalidEntityTypes)) {
+            throw new ParameterException('Invalid entity type: ' . $entityType);
+        }
+
+        return $lastRetrievedVersion > max($minimumVersion - 1, (int)$lastRetrievedVersion);
+    }
 }