added import and export recurring bills

app/Imports/Purchases/Bills/Sheets/BillTotals.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Imports\Purchases\Bills\Sheets;
+
+use App\Abstracts\Import;
+use App\Http\Requests\Document\DocumentTotal as Request;
+use App\Models\Document\Document;
+use App\Models\Document\DocumentTotal as Model;
+
+class BillTotals extends Import
+{
+    public $request_class = Request::class;
+
+    public function model(array $row)
+    {
+        return new Model($row);
+    }
+
+    public function map($row): array
+    {
+        if ($this->isEmpty($row, 'bill_number')) {
+            return [];
+        }
+
+        $row['bill_number'] = (string) $row['bill_number'];
+
+        $row = parent::map($row);
+
+        $row['document_id'] = (int) Document::bill()->number($row['bill_number'])->pluck('id')->first();
+        $row['type'] = Document::BILL_TYPE;
+
+        return $row;
+    }
+
+    public function prepareRules(array $rules): array
+    {
+        $rules['bill_number'] = 'required|string';
+
+        unset($rules['bill_id']);
+
+        return $rules;
+    }
+}