Invoices can be uploaded

app/Providers/UploadFileProvider.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace App\Providers;
+
+use App\Models\CostUnit;
+use App\ValueObjects\InvoiceFile;
+use Illuminate\Http\UploadedFile;
+use Illuminate\Support\Facades\Storage;
+
+class UploadFileProvider {
+    private UploadedFile $file;
+    private CostUnit $costUnit;
+
+    public function __construct(UploadedFile $file, CostUnit $costUnit) {
+        $this->file = $file;
+        $this->costUnit = $costUnit;
+    }
+
+    public function saveUploadedFile() : ?InvoiceFile {
+        try {
+            $directory = sprintf(
+                '%1$s/invoices/%2$s',
+                app('tenant')->slug,
+                $this->costUnit->id
+            );
+
+            $filename = $this->normalizeFilename($this->file->getClientOriginalName());
+
+            $path = $this->file->storeAs(
+                $directory,
+                $filename
+            );
+
+            $invoiceFile = new InvoiceFile();
+            $invoiceFile->filename = $filename;
+            $invoiceFile->path = $path;
+            return $invoiceFile;
+        } catch (\Exception $e) {
+            return null;
+        }
+    }
+
+    private function normalizeFilename(string $filename) : string {
+        return strtolower($filename)
+            |> function (string $filename) : string { return str_replace(' ', '_', $filename); }
+            |> function (string $filename) : string { return str_replace('ä', 'ae', $filename); }
+            |> function (string $filename) : string { return str_replace('ö', 'oe', $filename); }
+            |> function (string $filename) : string { return str_replace('ü', 'ue', $filename); }
+            |> function (string $filename) : string { return str_replace('ß', 'ss', $filename); };
+
+    }
+}