fixed bug regarding wrong calculation for subproductsubstitution

services/StockService.php

@@ -406,17 +406,15 @@ class StockService extends BaseService
 				$potentialStockEntries = FindAllObjectsInArrayByPropertyValue($potentialStockEntries, 'stock_id', $specificStockEntryId);
 			}
 
-			$productStockAmount = floatval($productDetails->stock_amount_aggregated);
-			if ($amount > $productStockAmount)
-			{
-				throw new \Exception('Amount to be consumed cannot be > current stock amount (if supplied, at the desired location)');
-			}
-
 			if ($transactionId === null)
 			{
 				$transactionId = uniqid();
 			}
 
+			//first simulate stock consumption. Otherwhise calculations are wrong when stock units of parent and child products have a big conversion factor
+			$stockeEntriesToConsume = [];
+
+			// collect all stockentries
 			foreach ($potentialStockEntries as $stockEntry)
 			{
 				if ($amount == 0)
@@ -431,13 +429,51 @@ class StockService extends BaseService
 					$conversion = $this->getDatabase()->quantity_unit_conversions_resolved()->where('product_id = :1 AND from_qu_id = :2 AND to_qu_id = :3', $stockEntry->product_id, $productDetails->product->qu_id_stock, $subProduct->qu_id_stock)->fetch();
 					if ($conversion != null)
 					{
-						$amount = $amount * floatval($conversion->factor);
+						//remember factor for later
+						$factor = floatval($conversion->factor);
+						$amount = $amount * $factor;
+					}else{
+						//fail when no conversion is provided, calculattions will be wrong otherwhise
+						throw new \Exception('No conversion from child to parent product');
 					}
 				}
 
+				//collect data
 				if ($amount >= $stockEntry->amount)
 				{
+					$stockeEntriesToConsume[] = [
+						"entry" => $stockEntry,
+						"amount" => $stockEntry->amount
+					];
+
+					$amount -= $stockEntry->amount;
+				}
+				else
+				{
+					$stockeEntriesToConsume[] = [
+						"entry" => $stockEntry,
+						"amount" => $amount
+					];
+
+
+					$amount = 0;
+				}
+
+				// convert back when $amount had been scaled beforehand
+				if ($allowSubproductSubstitution && $stockEntry->product_id != $productId){
+					$amount=$amount/$factor;
+				}
+
+
+			}
+
+			//only when stock can be fullfilled, persist it
+			if($amount<=0){
+				foreach($stockeEntriesToConsume as $entry){
+					$stockEntry = $entry['entry'];
+					$amount = $entry['amount'];
 					// Take the whole stock entry
+					if($amount==$stockEntry->amount){
 						$logRow = $this->getDatabase()->stock_log()->createRow([
 							'product_id' => $stockEntry->product_id,
 							'amount' => $stockEntry->amount * -1,
@@ -458,11 +494,7 @@ class StockService extends BaseService
 						$logRow->save();
 
 						$stockEntry->delete();
-
+					}else{
-					$amount -= $stockEntry->amount;
-				}
-				else
-				{
 						// Stock entry amount is > than needed amount -> split the stock entry resp. update the amount
 						$restStockAmount = $stockEntry->amount - $amount;
 
@@ -488,10 +520,11 @@ class StockService extends BaseService
 						$stockEntry->update([
 							'amount' => $restStockAmount
 						]);
-
-					$amount = 0;
 					}
 				}
+			}else{
+				throw new \Exception('Amount to be consumed cannot be > current stock amount (if supplied, at the desired location)');
+			}
 
 			if (boolval($this->getUsersService()->GetUserSetting(GROCY_USER_ID, 'shopping_list_auto_add_below_min_stock_amount')))
 			{