Kent-logistics-Laravel/app/Models/InvoiceItem.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class InvoiceItem extends Model
{
    use HasFactory;

    protected $fillable = [
        'invoice_id',

        'description',
        'ctn',
        'qty',
        'ttl_qty',
        'unit',
        'price',
        'ttl_amount',

        'cbm',
        'ttl_cbm',

        'kg',
        'ttl_kg',

        'shop_no',
    ];

    /****************************
     * Relationships
     ****************************/

    public function invoice()
    {
        return $this->belongsTo(Invoice::class);
    }


    public function chargeGroupItems()
    {
        return $this->hasMany(InvoiceChargeGroupItem::class, 'invoice_item_id');
    }

    // हे helper: पहिला group fetch करून त्यावरून rate/total काढणे
    public function getChargeRateAttribute()
    {
        $pivot = $this->chargeGroupItems->first();
        if (!$pivot || !$pivot->group) {
            return 0;
        }

        $group = $pivot->group;

        // basis नुसार या item चा basis value
        $basis = 0;
        switch ($group->basis_type) {
            case 'ttl_qty':
                $basis = $this->ttl_qty;
                break;
            case 'amount':
                $basis = $this->ttl_amount;
                break;
            case 'ttl_cbm':
                $basis = $this->ttl_cbm;
                break;
            case 'ttl_kg':
                $basis = $this->ttl_kg;
                break;
        }

        if ($basis <= 0 || ($group->basis_value ?? 0) <= 0) {
            return 0;
        }

        // group चा rate field आधीच आहे, ते direct वापरू
        return (float) $group->rate;
    }

    public function getChargeTotalAttribute()
    {
        $pivot = $this->chargeGroupItems->first();
        if (!$pivot || !$pivot->group) {
            return 0;
        }

        $group = $pivot->group;

        $basis = 0;
        switch ($group->basis_type) {
            case 'ttl_qty':
                $basis = $this->ttl_qty;
                break;
            case 'amount':
                $basis = $this->ttl_amount;
                break;
            case 'ttl_cbm':
                $basis = $this->ttl_cbm;
                break;
            case 'ttl_kg':
                $basis = $this->ttl_kg;
                break;
        }

        if ($basis <= 0 || ($group->basis_value ?? 0) <= 0) {
            return 0;
        }

        // per unit rate
        $rate = (float) $group->rate;
        // item total = basis * rate
        return $basis * $rate;
    }
}