major progress

_config/config.yml

@@ -5,6 +5,12 @@ Name: stockconfig
 SilverCommerce\CatalogueAdmin\Model\CatalogueProduct:
   extensions:
     - SilverCommerce\Stock\Extensions\ProductExtension
-SilverCommerce\Checkout\Control\Checkout:
+SilverCommerce\OrdersAdmin\Model\LineItem:
   extensions:
-    - SilverCommerce\Stock\Extensions\CheckoutExtension
+    - SilverCommerce\Stock\Extensions\LineItemExtension
+SilverCommerce\OrdersAdmin\Model\Invoice:
+  extensions:
+    - SilverCommerce\Stock\Extensions\InvoiceExtension
+SilverCommerce\CatalogueAdmin\Admin\CatalogueAdmin:
+  extensions:
+    - SilverCommerce\Stock\Extensions\CatalogueAdminExtension

src/Control/StockController.php

@@ -24,8 +24,7 @@ class StockController extends Controller
     public function reduceStock($item, $quantity) 
     {
         $item->StockLevel -= $quantity;
-        if ($item->StockLevel < 0) {
-            $item->StockLevel = 0;
+        if ($item->StockLevel < 0 && $this->email_alerts) {
             $this->alertOversold($item);
         }
         $item->write();
@@ -35,13 +34,16 @@ public function reduceStock($item, $quantity)
         }
     }
 
+    /** ### TO DO ### **/ #################################################################
     public function alertOversold($item) 
     {
         // send email alerting stocklevel mismatch
+        return null;
     }
 
     public function alertLowStock($item) 
     {
         // send email alerting low stock level
+        return null;
     }
 }

src/Extensions/CatalogueAdminExtension.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace SilverCommerce\Stock\Extensions;
+
+use Product;
+use SilverStripe\Core\Extension;
+use SilverStripe\GridFieldAddOns\GridFieldRecordHighlighter;
+
+class CatalogueAdminExtension extends Extension
+{
+    public function updateEditForm($form)
+    {
+        $fields = $form->Fields();
+        $grid = $fields
+        ->fieldByName($this->sanitiseClassName($this->owner->modelClass));
+        if ($this->owner->modelClass == Product::class && $grid) {
+            $config = $grid->getConfig();
+            $alerts = [
+                'isStockLow' => [
+                    'comparator' => 'equal',
+                    'patterns' => [
+                        true => [
+                            'status' => 'info',
+                            'message' => 'This product is low on stock'
+                        ]
+                    ]
+                ],
+                'StockLevel' => [
+                    'comparator' => 'lessorequal',
+                    'patterns' => [
+                        0 => [
+                            'status' => 'error',
+                            'message' => 'This product is out of stock'
+                        ]
+                    ]
+                ]
+            ];
+            $config->addComponent(new GridFieldRecordHighlighter($alerts));
+        }
+    }
+    /**
+     * Sanitise a model class' name for inclusion in a link
+     *
+     * @param string $class
+     * @return string
+     */
+    protected function sanitiseClassName($class)
+    {
+        return str_replace('\\', '-', $class);
+    }
+}

src/Extensions/InvoiceExtension.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace SilverCommerce\Stock\Extensions;
+
+use SilverStripe\ORM\DataExtension;
+use SilverStripe\ORM\ValidationException;
+
+class InvoiceExtension extends DataExtension
+{
+    public function onBeforeWrite()
+    {
+        if ($this->owner->isChanged('Status')) {
+            $statuses = $this->owner->config()->get("paid_statuses");
+            $changed = $this->owner->getChangedFields()['Status'];
+            $old = $changed['before'];
+            $new = $changed['after'];
+            if (!in_array($old, $statuses) && in_array($new, $statuses)) {
+                $items = $this->owner->Items();
+                foreach ($items as $item) {
+                    $match = $item->FindStockItem();
+                    if ($match && $match->Stocked) {
+                        if ($item->checkStockLevel($item->Quantity) < 0) {
+                            throw new ValidationException(_t(
+                                "ShoppingCart.NotEnoughStock",
+                                "There are not enough '{title}' in stock",
+                                ['title' => $match->Title]
+                            ));
+                        }
+                        $match->StockLevel -= $item->Quantity;
+                        $match->write();
+                    }
+                }
+            }
+        }
+    }
+}

src/Extensions/LineItemExtension.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace SilverCommerce\Stock\Extensions;
+
+use SilverStripe\ORM\DataExtension;
+use SilverStripe\ORM\ValidationException;
+use SilverCommerce\OrdersAdmin\Model\Invoice;
+
+class LineItemExtension extends DataExtension
+{
+    public function onBeforeWrite()
+    {
+        $match = $this->owner->FindStockItem();
+        $parent = $this->owner->Parent();
+        if ($match && $match->Stocked && $parent instanceof Invoice && $parent->isPaid()) {
+            $qty = 0;
+            $old = 0;
+            if (!$this->owner->ID) {
+                $qty = $this->owner->Quantity;    
+            } else if ($this->owner->isChanged('Quantity')) {
+                $changed = $this->owner->getChangedFields()['Quantity'];
+                $old = $changed['before'];
+                $new = $changed['after'];
+                $qty = $new - $old;
+            }
+            if ($qty > 0 && $this->owner->checkStockLevel($qty) < 0) {
+                $this->owner->Quantity =  $old + $match->StockLevel;
+                throw new ValidationException(_t(
+                    "ShoppingCart.NotEnoughStock",
+                    "There are not enough '{title}' in stock",
+                    ['title' => $match->Title]
+                ));
+            }
+            $match->StockLevel -= $qty;
+            $match->write();
+        }
+    }
+}

src/Extensions/ProductExtension.php

@@ -41,10 +41,10 @@ public function updateCMSFields(FieldList $fields)
      */
     public function isStockLow()
     {
-        if ($this->Stocked) {
-            return $stock = $this->StockLevel < $this->LowStock ? true : false;
+        if ($this->owner->Stocked) {
+            return $stock = $this->owner->StockLevel < $this->owner->LowStock ? true : false;
         }
-        return true;
+        return false;
     }
 
     /**
@@ -55,8 +55,8 @@ public function isStockLow()
      */    
     public function checkStockLevel($qty = 0) 
     {
-        if ($this->Stocked) {
-            return $this->StockLevel - $qty;
+        if ($this->owner->Stocked) {
+            return $this->owner->StockLevel - $qty;
         } 
         return true;
     }