update

autoload/Domain/Finances/FakturowniaInvoiceImporter.php

@@ -128,6 +128,12 @@ class FakturowniaInvoiceImporter
       return 'skipped';
 
     $clientMap = $this -> repo -> getClientMapping( $document['client_key'] );
+    if ( !$clientMap && $document['legacy_client_key'] !== '' && $document['legacy_client_key'] !== $document['client_key'] )
+    {
+      // Backward compatibility for historical mappings saved as id:{client_id}.
+      $clientMap = $this -> repo -> getClientMapping( $document['legacy_client_key'] );
+    }
+
     if ( !$clientMap )
     {
       $this -> repo -> queueUnmapped( 'client', $document['client_key'], $document['client_name'], [
@@ -331,6 +337,7 @@ class FakturowniaInvoiceImporter
       'client_name' => $clientName,
       'client_tax_no' => $clientTaxNo,
       'client_key' => $this -> buildClientKey( $rawDocument, $clientName, $clientTaxNo ),
+      'legacy_client_key' => $this -> buildLegacyClientKey( $rawDocument ),
       'positions' => $positions,
       'total_amount' => $this -> normalizeAmount( $totalAmount, $documentType )
     ];
@@ -379,14 +386,33 @@ class FakturowniaInvoiceImporter
   }
 
   private function buildClientKey( $rawDocument, $clientName, $clientTaxNo )
+  {
+    $normalizedTaxNo = $this -> normalizeTaxNo( $clientTaxNo );
+    if ( $normalizedTaxNo !== '' )
+      return 'tax:' . $normalizedTaxNo;
+
+    $legacyClientKey = $this -> buildLegacyClientKey( $rawDocument );
+    if ( $legacyClientKey !== '' )
+      return $legacyClientKey;
+
+    return 'name:' . $this -> normalizeKeyValue( $clientName );
+  }
+
+  private function buildLegacyClientKey( $rawDocument )
   {
     if ( isset( $rawDocument['client_id'] ) && (string)$rawDocument['client_id'] !== '' )
       return 'id:' . (string)$rawDocument['client_id'];
 
-    if ( $clientTaxNo !== '' )
-      return 'tax:' . preg_replace( '/\s+/', '', $clientTaxNo );
+    return '';
+  }
 
-    return 'name:' . $this -> normalizeKeyValue( $clientName );
+  private function normalizeTaxNo( $taxNo )
+  {
+    $normalizedTaxNo = preg_replace( '/\D+/', '', (string)$taxNo );
+    if ( !is_string( $normalizedTaxNo ) || $normalizedTaxNo === '' )
+      return '';
+
+    return $normalizedTaxNo;
   }
 
   private function buildItemKey( $rawPosition, $name )