refactor(modular): 完成第二階段儀表板解耦與模型清理

app/Modules/Inventory/Services/InventoryService.php

@@ -40,6 +40,11 @@ class InventoryService implements InventoryServiceInterface
         return Product::whereIn('id', $ids)->get();
     }
 
+    public function getProductsByName(string $name)
+    {
+        return Product::where('name', 'like', "%{$name}%")->get();
+    }
+
     public function getWarehouse(int $id)
     {
         return Warehouse::find($id);
@@ -182,4 +187,24 @@ class InventoryService implements InventoryServiceInterface
             ]);
         });
     }
+
+    public function getDashboardStats(): array
+    {
+        // 庫存總表 join 安全庫存表，計算低庫存
+        $lowStockCount = DB::table('warehouse_product_safety_stocks as ss')
+            ->join(DB::raw('(SELECT warehouse_id, product_id, SUM(quantity) as total_qty FROM inventories WHERE deleted_at IS NULL GROUP BY warehouse_id, product_id) as inv'),
+                function ($join) {
+                    $join->on('ss.warehouse_id', '=', 'inv.warehouse_id')
+                         ->on('ss.product_id', '=', 'inv.product_id');
+                })
+            ->whereRaw('inv.total_qty <= ss.safety_stock')
+            ->count();
+
+        return [
+            'productsCount' => Product::count(),
+            'warehousesCount' => Warehouse::count(),
+            'lowStockCount' => $lowStockCount,
+            'totalInventoryQuantity' => Inventory::sum('quantity'),
+        ];
+    }
 }