opensourcepos/app/Models/Tokens/Token_invoice_count.php

<?php

namespace App\Models\Tokens;

use App\Models\Sale;

/**
 * Token_invoice_count class
 *
 * @property sale sale
 *
 */
class Token_invoice_count extends Token
{
	public function __construct(string $value = '')
	{
		parent::__construct($value);
	}

	public function token_id(): string
	{
		return 'CO';
	}

	public function get_value(): int
	{
		$sale = model(Sale::class);
		return empty($value) ? $sale->get_invoice_count() : $value;
	}
}