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

<?php

namespace App\Models;

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

class Invoice extends Model
{
    use HasFactory;

    protected $fillable = [
        'container_id',
        'customer_id',
        'mark_no',
        'invoice_number',
        'invoice_date',
        'due_date',
        'payment_method',
        'reference_no',
        'status',
        'final_amount',
        'gst_percent',
        'gst_amount',
        'final_amount_with_gst',
        'customer_name',
        'company_name',
        'customer_email',
        'customer_mobile',
        'customer_address',
        'pincode',
        'pdf_path',
        'notes',
    ];

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

    public function items()
    {
        return $this->hasMany(InvoiceItem::class)->orderBy('id', 'ASC');
    }

    public function container()
    {
        return $this->belongsTo(Container::class);
    }

    public function customer()
    {
        return $this->belongsTo(User::class, 'customer_id');
    }

    public function installments()
    {
        return $this->hasMany(InvoiceInstallment::class);
    }

    // ✅ SINGLE, correct relation
    public function chargeGroups()
    {
        return $this->hasMany(\App\Models\InvoiceChargeGroup::class, 'invoice_id');
    }

    /****************************
     * Helper Functions
     ****************************/

    public function calculateTotals()
    {
        $gst = ($this->final_amount * $this->gst_percent) / 100;
        $this->gst_amount            = $gst;
        $this->final_amount_with_gst = $this->final_amount + $gst;
    }

    public function isOverdue()
    {
        return $this->status === 'pending' && now()->gt($this->due_date);
    }

    public function getShipment()
    {
        return null;
    }

    // ✅ Charge groups total accessor
    public function getChargeGroupsTotalAttribute()
    {
        // relation already loaded असेल तर collection वरून sum होईल
        return (float) $this->chargeGroups->sum('total_charge');
    }

    // ✅ Grand total accessor (items + GST + charge groups)
    public function getGrandTotalWithChargesAttribute()
    {
        return (float) ($this->final_amount_with_gst ?? 0) + $this->charge_groups_total;
    }

    public function totalPaid()
{
    return $this->installments->sum('amount');
}


public function remainingAmount()
{
    return $this->grand_total_with_charges - $this->totalPaid();
}


}