<?php

namespace App\Traits;

trait EagerLoad
{
    protected static $eagerLoaded = [];
    
    /**
     * Eager load a items in model.
     * 
     * @param  array $ids The ids to eager load.
     * @return void
     */
    public static function eagerLoad($ids)
    {
        self::addItems( self::whereIn('id', $ids)->get() );
    }

    /**
     * Remove items from list of eager loaded items.
     * 
     * @param  array $ids The ids to remove.
     * @return void
     */
    public static function removeEagerLoaded($ids)
    {
        self::$eagerLoaded = array_diff_key(self::$eagerLoaded, array_flip($ids));
    }

    /**
     * Find eager loaded or find from database.
     *
     * @param  int      $id    The ID to find.
     * @return object
     */
    public static function findEagerLoaded($id)
    {
        if (isset(self::$eagerLoaded[$id])) {
            return self::$eagerLoaded[$id];
        }

        $item = self::find($id);

        self::addItem($id, $item);

        return $item;
    }

    private static function addItems($items)
    {
        if (empty($items)) {
            return false;
        }

        foreach($items as $item) {
            self::$eagerLoaded[$item->id] = $item;
        }
    }

    private static function addItem($id, $item)
    {
        if ($item) {
            self::$eagerLoaded[$id] = $item;
        }
    }


}