generate bill number

app/Http/Controllers/Purchases/Bills.php

@@ -108,7 +108,9 @@ class Bills extends Controller
 
         $categories = Category::type('expense')->enabled()->orderBy('name')->pluck('name', 'id');
 
-        return view('purchases.bills.create', compact('vendors', 'currencies', 'currency', 'items', 'taxes', 'categories'));
+        $number = $this->getNextBillNumber();
+
+        return view('purchases.bills.create', compact('vendors', 'currencies', 'currency', 'items', 'taxes', 'categories', 'number'));
     }
 
     /**

app/Listeners/Purchase/IncreaseNextBillNumber.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace App\Listeners\Purchase;
+
+use App\Events\Purchase\BillCreated as Event;
+use App\Traits\Purchases;
+
+class IncreaseNextBillNumber
+{
+    use Purchases;
+
+    /**
+     * Handle the event.
+     *
+     * @param  $event
+     * @return void
+     */
+    public function handle(Event $event)
+    {
+        // Update next bill number
+        $this->increaseNextBillNumber();
+    }
+}

app/Models/Purchase/Bill.php

@@ -99,5 +99,6 @@ class Bill extends DocumentModel
     public function onCloning($src, $child = null)
     {
         $this->status = 'draft';
+        $this->bill_number = $this->getNextBillNumber();
     }
 }

app/Providers/Event.php

@@ -25,6 +25,7 @@ class Event extends Provider
         ],
         'App\Events\Purchase\BillCreated' => [
             'App\Listeners\Purchase\CreateBillCreatedHistory',
+            'App\Listeners\Purchase\IncreaseNextBillNumber',
         ],
         'App\Events\Purchase\BillReceived' => [
             'App\Listeners\Purchase\MarkBillReceived',

app/Traits/Purchases.php

@@ -4,6 +4,33 @@ namespace App\Traits;
 
 trait Purchases
 {
+    /**
+     * Generate next bill number
+     *
+     * @return string
+     */
+    public function getNextBillNumber()
+    {
+        $prefix = setting('bill.number_prefix', 'BIL-');
+        $next = setting('bill.number_next', '1');
+        $digit = setting('bill.number_digit', '5');
+
+        $number = $prefix . str_pad($next, $digit, '0', STR_PAD_LEFT);
+
+        return $number;
+    }
+
+    /**
+     * Increase the next bill number
+     */
+    public function increaseNextBillNumber()
+    {
+        $next = setting('bill.number_next', 1) + 1;
+
+        setting(['bill.number_next' => $next]);
+        setting()->save();
+    }
+
     /**
      * Get a collection of bill statuses
      *