สูตรคำนวนราคาใหม่ BSO

<?php
use App\Model\WorkDescription;
use App\Model\WorkSelect;

function calNewPrice($workDescId, $qty, $option = null)
{

    $selects = WorkSelect::select(
        'select_id',
        'wd.work_desc_main_id',
        'work_selects.work_desc_id',
        'qty',
        'area_id'
    )
        ->join('work_descriptions AS wd', 'wd.work_desc_id', '=', 'work_selects.work_desc_id')
        ->where('work_selects.work_desc_id', $workDescId)
        ->get();

    $workDescId = $selects->pluck('work_desc_main_id');

    $workDescriptions = WorkDescription::with('work_cost')
        ->whereIn('work_desc_main_id', $workDescId)->get();

        $want = $qty; //จำนวนที่ต้องการ
        $sum = 0;
        $arrLaborCost = [];
        $arrConditionValue = [];
        $unitPrice = 0;

foreach ($workDescriptions as $workDescription) {

    $arrLaborCost[] = $workDescription->work_cost->labor_cost; //เก็บค่าแรงใส่ใน array
    $arrConditionValue[] = $workDescription->work_cost->condition_value; //เก็บเงื่อนไขใส่ใน array

           if ($workDescription->work_cost->case == 1) { //กรณีที่ 1 คูณจำนวนเข้าไปตรงๆเลย

            $sum = $workDescription->work_cost->labor_cost * $want;
            $unitPrice = $workDescription->work_cost->labor_cost;

           } elseif ($workDescription->work_cost->case == 2) { //กรณีที่ 2

               if ($workDescription->work_cost->condition == "less_equal_to") {
                   if ($want <= $workDescription->work_cost->condition_value) {
                    $sum = $workDescription->work_cost->labor_cost . "\n";
                    $unitPrice = $workDescription->work_cost->labor_cost;
                   }
               } elseif ($workDescription->work_cost->condition == "greater_equal_to") {
                   if ($want >= $workDescription->work_cost->condition_value) {
                    $sum = $want * $workDescription->work_cost->labor_cost;
                    $unitPrice = $workDescription->work_cost->labor_cost;
                   }
               }



           } elseif ($workDescription->work_cost->case == 3) { //กรณีที่ 3

               if ($workDescription->work_cost->condition == "less_equal_to") {

                   if ($want <= $workDescription->work_cost->condition_value) {
                       $sum = $workDescription->work_cost->labor_cost . "\n";
                       $unitPrice = $workDescription->work_cost->labor_cost;
                   }

               }

               if ($workDescription->work_cost->condition == "greater_equal_to") {
                   $difference = ($want - $arrConditionValue[0]); //หาส่วนต่าง

                   if ($want >= $workDescription->work_cost->condition_value) {
                       $sum = ($difference * $workDescription->work_cost->labor_cost) + $arrLaborCost[0]; //$arrLaborCost[0] ตือราคาแรก
                       $unitPrice = $workDescription->work_cost->labor_cost;
                       //echo $sum . "\n";
                   }
               }

           } //end if main
        } //end foreach

        if($option != '' && $option == 'unitPrice'){
            return $unitPrice;
        }else{
            return $sum;
        }


}