first pass

app/Jobs/Inventory/AdjustProductInventory.php

@@ -0,0 +1,95 @@
+<?php
+/**
+ * Invoice Ninja (https://invoiceninja.com).
+ *
+ * @link https://github.com/invoiceninja/invoiceninja source repository
+ *
+ * @copyright Copyright (c) 2022. Invoice Ninja LLC (https://invoiceninja.com)
+ *
+ * @license https://www.elastic.co/licensing/elastic-license
+ */
+
+namespace App\Jobs\Inventory;
+
+use App\Libraries\MultiDB;
+use App\Models\Company;
+use App\Models\Invoice;
+use App\Models\Product;
+use App\Utils\Traits\NumberFormatter;
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Foundation\Bus\Dispatchable;
+use Illuminate\Queue\InteractsWithQueue;
+use Illuminate\Queue\SerializesModels;
+
+//todo - ensure we are MultiDB Aware in dispatched jobs
+
+class AdjustProductInventory implements ShouldQueue
+{
+    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;
+
+    public Company $company;
+
+    public Invoice $invoice;
+
+    public array $old_invoice;
+
+    public function __construct(Company $company, Invoice $invoice, array $old_invoice = [])
+    {
+
+        $this->company = $company;
+        $this->invoice = $invoice;
+        $this->old_invoice = $old_invoice;
+    }
+
+    /**
+     * Execute the job.
+     *
+     *
+     * @return false
+     */
+    public function handle()
+    {
+        MultiDB::setDb($this->company->db);
+
+        if(count($this->old_invoice) > 0)
+            return $this->existingInventoryAdjustment();
+
+        return $this->newInventoryAdjustment();
+
+    }
+
+    private function newInventoryAdjustment()
+    {
+        
+        $line_items = $this->invoice->line_items;
+
+        foreach($line_items as $item)
+        {
+
+            $p = Product::where('product_key', $item->product_key)->where('company_id', $this->company->id)->where('in_stock_quantity', '>', 0)->first();
+            $p->in_stock_quantity -= $item->quantity;
+            $p->save();
+
+            //check threshols and notify user
+
+            if($p->stock_notification_threshold && $p->in_stock_quantity <= $p->stock_notification_threshold)
+                $this->notifyStockLevels($p, 'product');
+            elseif($this->company->stock_notification_threshold && $p->in_stock_quantity <= $this->company->stock_notification_threshold){
+                $this->notifyStocklevels($p, 'company');
+            }
+        }
+
+    }
+
+    private function existingInventoryAdjustment()
+    {
+
+    }
+
+    private function notifyStocklevels(Product $product, string $notification_level)
+    {
+
+    }
+
+}

app/Models/Company.php

@@ -103,6 +103,9 @@ class Company extends BaseModel
         'markdown_email_enabled',
         'stop_on_unpaid_recurring',
         'use_quote_terms_on_conversion',
+        'enable_applying_payments',
+        'track_inventory',
+        'inventory_notification_threshold',
     ];
 
     protected $hidden = [

app/Models/Product.php

@@ -36,6 +36,8 @@ class Product extends BaseModel
         'tax_rate1',
         'tax_rate2',
         'tax_rate3',
+        'in_stock_quantity',
+        'stock_notification_threshold',
     ];
 
     protected $touches = [];

app/Services/Invoice/InvoiceService.php

@@ -13,6 +13,7 @@ namespace App\Services\Invoice;
 
 use App\Events\Invoice\InvoiceWasArchived;
 use App\Jobs\Entity\CreateEntityPdf;
+use App\Jobs\Inventory\AdjustProductInventory;
 use App\Jobs\Invoice\InvoiceWorkflowSettings;
 use App\Jobs\Util\UnlinkFile;
 use App\Libraries\Currency\Conversion\CurrencyApi;
@@ -564,6 +565,14 @@ class InvoiceService
         return $this;
     }
 
+    public function adjustInventory()
+    {
+        if($this->invoice->company->track_inventory)
+            AdjustProductInventory::dispatch($this->invoice->company, $this->invoice, null);
+
+        return $this;
+    }
+
     /**
      * Saves the invoice.
      * @return Invoice object

database/migrations/2022_05_31_101504_inventory_management_schema.php

@@ -0,0 +1,43 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class InventoryManagementSchema extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+
+
+        Schema::table('companies', function (Blueprint $table) {
+            $table->boolean('enable_applying_payments')->default(0);
+            $table->boolean('track_inventory')->default(0);
+            $table->integer('inventory_notification_threshold')->nullable();
+
+        });
+
+        Schema::table('products', function (Blueprint $table){
+            $table->integer('in_stock_quantity')->nullable();
+            $table->integer('stock_notification_threshold')->nullable();
+        });
+
+
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        //
+    }
+}
+