Added a filter constraint for parts where instock is "less than desired"

Fixes issue #257

src/DataTables/Filters/Constraints/Part/LessThanDesiredConstraint.php

@@ -0,0 +1,47 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2023 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published
+ *  by the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+namespace App\DataTables\Filters\Constraints\Part;
+
+use App\DataTables\Filters\Constraints\BooleanConstraint;
+use Doctrine\ORM\QueryBuilder;
+
+class LessThanDesiredConstraint extends BooleanConstraint
+{
+    public function __construct(string $property = null, string $identifier = null, ?bool $default_value = null)
+    {
+        parent::__construct($property ?? 'amountSum', $identifier, $default_value);
+    }
+
+    public function apply(QueryBuilder $queryBuilder): void
+    {
+        //Do not apply a filter if value is null (filter is set to ignore)
+        if(!$this->isEnabled()) {
+            return;
+        }
+
+        //If value is true, we want to filter for parts with stock < desired stock
+        if ($this->value) {
+            $queryBuilder->andHaving('amountSum < part.minamount');
+        } else {
+            $queryBuilder->andHaving('amountSum >= part.minamount');
+        }
+    }
+}

src/DataTables/Filters/PartFilter.php

@@ -26,6 +26,7 @@ use App\DataTables\Filters\Constraints\DateTimeConstraint;
 use App\DataTables\Filters\Constraints\EntityConstraint;
 use App\DataTables\Filters\Constraints\IntConstraint;
 use App\DataTables\Filters\Constraints\NumberConstraint;
+use App\DataTables\Filters\Constraints\Part\LessThanDesiredConstraint;
 use App\DataTables\Filters\Constraints\Part\ParameterConstraint;
 use App\DataTables\Filters\Constraints\Part\TagsConstraint;
 use App\DataTables\Filters\Constraints\TextConstraint;
@@ -68,6 +69,15 @@ class PartFilter implements FilterInterface
     protected EntityConstraint $storelocation;
     protected IntConstraint $lotCount;
     protected IntConstraint $amountSum;
+    protected LessThanDesiredConstraint $lessThanDesired;
+
+    /**
+     * @return LessThanDesiredConstraint
+     */
+    public function getLessThanDesired(): LessThanDesiredConstraint
+    {
+        return $this->lessThanDesired;
+    }
     protected BooleanConstraint $lotNeedsRefill;
     protected TextConstraint $lotDescription;
     protected BooleanConstraint $lotUnknownAmount;
@@ -108,6 +118,7 @@ class PartFilter implements FilterInterface
         //We have to use Having here, as we use an alias column which is not supported on the where clause and would result in an error
         $this->amountSum = (new IntConstraint('amountSum'))->useHaving();
         $this->lotCount = new IntConstraint('COUNT(partLots)');
+        $this->lessThanDesired = new LessThanDesiredConstraint();
 
         $this->storelocation = new EntityConstraint($nodesListBuilder, Storelocation::class, 'partLots.storage_location');
         $this->lotNeedsRefill = new BooleanConstraint('partLots.needs_refill');

src/Form/Filters/PartFilterType.php

@@ -206,6 +206,10 @@ class PartFilterType extends AbstractType
             'min' => 0,
         ]);
 
+        $builder->add('lessThanDesired', BooleanConstraintType::class, [
+            'label' => 'part.filter.lessThanDesired'
+        ]);
+
         $builder->add('lotNeedsRefill', BooleanConstraintType::class, [
             'label' => 'part.filter.lotNeedsRefill'
         ]);