Fix on invoices, add delivery reference, wip on dashboard concurrency requests designed on template

app/Repositories/Core/DateStats.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace App\Repositories\Core;
+
+use Carbon\Carbon;
+use Illuminate\Database\Eloquent\Model;
+
+Trait DateStats
+{
+    public static function countByMonth($prev = 0)
+    {
+        $start = Carbon::now()->startOfMonth($prev);
+        $end = Carbon::now()->endOfMonth($prev);
+        return self::countByPeriod($start, $end);
+    }
+
+    public static function countByPeriod($start, $end, $field = 'created_at')
+    {
+        return self::getModel()->whereBetween($field, [$start, $end])->count();
+    }
+
+    public static function avgByMonth($prev = 0, $field = false)
+    {
+        $start = Carbon::now()->startOfMonth($prev);
+        $end = Carbon::now()->endOfMonth($prev);
+        return self::avgByPeriod($start, $end, $field);
+    }
+
+    public static function avgByPeriod($start, $end, $field)
+    {
+        $c = self::countByPeriod($start, $end);
+        return $c ? round(self::sumByPeriod($start, $end, $field) / $c, 2) : 0;
+    }
+
+    public static function sumByMonth($prev = 0, $field = false)
+    {
+        $start = Carbon::now()->startOfMonth($prev);
+        $end = Carbon::now()->endOfMonth($prev);
+        return self::sumByPeriod($start, $end, $field);
+    }
+
+    public static function sumByPeriod($start, $end, $field = 'created_at')
+    {
+        return self::getModel()->whereBetween($field, [$start, $end])->sum($field);
+    }
+
+    public static function getModel()
+    {
+        return new Model;
+    }
+}