support tags in invoices (#2526)

src/Invoice/Calculator/AbstractMergedCalculator.php

@@ -114,5 +114,11 @@ abstract class AbstractMergedCalculator extends AbstractCalculator
         if (empty($invoiceItem->getDescription()) && null !== $entry->getActivity()) {
             $invoiceItem->setDescription($entry->getActivity()->getName());
         }
+
+        if ($entry instanceof Timesheet) {
+            foreach ($entry->getTagsAsArray() as $tag) {
+                $invoiceItem->addTag($tag);
+            }
+        }
     }
 }

src/Invoice/Hydrator/InvoiceItemDefaultHydrator.php

@@ -62,6 +62,7 @@ class InvoiceItemDefaultHydrator implements InvoiceItemHydrator
             'entry.description' => $description,
             'entry.amount' => $amount,
             'entry.type' => $item->getType(),
+            'entry.tags' => implode(', ', $item->getTags()),
             'entry.category' => $item->getCategory(),
             'entry.rate' => $formatter->getFormattedMoney($appliedRate, $currency),
             'entry.rate_nc' => $formatter->getFormattedMoney($appliedRate, $currency, false),

src/Invoice/InvoiceItem.php

@@ -75,6 +75,10 @@ final class InvoiceItem
      * @var string
      */
     private $category;
+    /**
+     * @var string[]
+     */
+    private $tags = [];
 
     public function addAdditionalField(string $name, ?string $value): InvoiceItem
     {
@@ -269,4 +273,23 @@ final class InvoiceItem
 
         return $this;
     }
+
+    public function addTag(string $tag): void
+    {
+        foreach ($this->tags as $t) {
+            if (strcasecmp($tag, $t) === 0) {
+                return;
+            }
+        }
+
+        $this->tags[] = $tag;
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getTags(): array
+    {
+        return $this->tags;
+    }
 }