/** * Return the total cost for all calls given. * @param Illuminate\Database\Eloquent\Collection $collection * @return String */ private static function calculateTotalCost($collection) { $calls = $collection->all(); $seconds = 0; foreach ($calls as $call) { $seconds = $seconds + $call->totaltime; } $minutes = $seconds / 60; // convert billing seconds to minutes. $totalCost = $minutes * env('AVG_COST_PER_MIN'); return number_format($totalCost, 2); }