Downloading files, calculating video size.

app/Models/Course.php

@@ -2,6 +2,7 @@
 
 namespace App\Models;
 
+use Illuminate\Database\Eloquent\Casts\Attribute;
 use Carbon\Traits\Date;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
@@ -16,6 +17,7 @@ use Illuminate\Database\Eloquent\Relations\HasMany;
  * @property integer $numberofchapters
  * @property integer $timeswatched
  * @property Date $published_at
+ * @property Chapter[] $chapters
  */
 class Course extends Model
 {
@@ -39,4 +41,22 @@ class Course extends Model
     {
         return $this->hasMany(Chapter::class);
     }
+
+    public function totalSize(): Attribute
+    {
+        return Attribute::make(
+            get: fn() => $this->chapters->sum('video_size'),
+        );
+    }
+
+    public function totalSizeHuman(): Attribute
+    {
+        return Attribute::make(
+            get: function () {
+                $base = log($this->total_size) / log(1024);
+                $suffix = ["", "k", "M", "G", "T"][floor($base)];
+                return round(pow(1024, $base - floor($base)), 2) . $suffix;
+            },
+        );
+    }
 }