Add interval between remiders sent

packages/Webkul/Sales/src/Traits/InvoiceReminder.php

@@ -34,6 +34,22 @@ trait InvoiceReminder
         return $remindersLimit = (int) core()->getConfigData('sales.invoice_setttings.invoice_reminders.reminders_limit');
     }
 
+    /**
+     * Get interval between reminders.
+     *
+     * @return string
+     */
+    private function getIntervalBetweenReminders()
+    {
+        static $intervalBetweenReminders;
+
+        if ($intervalBetweenReminders) {
+            return $intervalBetweenReminders;
+        }
+
+        return $intervalBetweenReminders = core()->getConfigData('sales.invoice_setttings.invoice_reminders.interval_between_reminders') ?: 'P1D';
+    }
+
     /**
      * Send an Invoice reminder
      *
@@ -51,6 +67,12 @@ trait InvoiceReminder
         $customer = $this->customer;
         Mail::queue(new InvoiceOverdueReminder($customer, $this));
         $this->reminders++;
+        // Calculate next reminder date
+        $date = now();
+        $interval = $this->getIntervalBetweenReminders();
+        $date->add($interval);
+        $date->setTime(0, 0, 0, 0);
+        $this->next_reminder_date = $date;
         $this->save();
     }
 
@@ -60,6 +82,13 @@ trait InvoiceReminder
     public function scopeInOverdueAndRemindersLimit($query)
     {
         $query->where('state', '=', 'overdue');
+        // Filter by next_reminder_date
+        $query->where(function($query) {
+            $query->where('next_reminder_at', '<=', now())
+            ->orWhereNull('next_reminder_at');
+        });
+
+        // If the core config have maximum limit of reminders
         if ($this->hasOverdueRemindersLimit()) {
             $limit = $this->getOverdueRemindersLimit();
             return $query->where('reminders', '<', $limit);