Writing SQL Query in Laravel Eloquent Way

I have this SQL Query

"SELECT
		MIN(IF(c.description IS NOT NULL, c.description, yec.cat_desc)) AS cat_desc,
		SUM(yec.{$time_period->yec_kwh_used}) AS kwh_used,
		SUM(yec.{$time_period->yec_cost}) AS cost,
		yec.category_id
	FROM `{$time_period->yec_table}` AS yec
	LEFT JOIN category AS c ON yec.category_id = c.id
	WHERE
		yec.category_id <> '$billing_category'
		AND yec.building_id = '$building->id'
		AND yec.category_id NOT IN (SELECT category_id FROM building_category_settings WHERE building_id = '$building->id' AND hide_from_electricity_widget = 1)
	GROUP BY category_id
	ORDER BY kwh_used DESC
";

But i am trying to write in laravel way i tried doing this

$electCategory = $this->electricityConnections->select(\DB::raw("MIN(IF(c.description IS NOT NULL, c.description, yec_cat_desc)) AS cat_desc", 
        ('SUM(yec.kwh_used) as khw_used'), ('SUM(yec.cost) as cost'), 'yec.category_id' ))
        ->leftJoin('category as c')
        ->first();

But it is not displaying what i want i am getting this error Too few arguments to function Illuminate\\Database\\Query\\Builder::leftJoin()

I have a your_electricity_yesterday_category table that has cost , khw_used, cat_desc andcategory_id as column.

Any help would be appreciated