<?php defined('SYSPATH') or die('No direct access allowed.');

/**
 * This class provides invoice information
 *
 * @package    OSB
 * @subpackage Invoice
 * @category   Helpers
 * @author     Deon George
 * @copyright  (c) 2010 Deon George
 * @license    http://dev.leenooks.net/license.html
 */
class Invoice {
	public static function instance() {
		return new Invoice;
	}

	/**
	 * Return a list of invoices for an invoice
	 *
	 * @param $id int Service ID
	 * @param $paid boolean Optionally only list the ones that are not paid.
	 * @return array
	 */
	public static function servicelist($id,$paid=TRUE) {
		// @todo need to add the db prefix
		$invoices = DB::Query(Database::SELECT,'
SELECT i.id AS iid,i.due_date AS due FROM ab_invoice i,ab_invoice_item ii WHERE ii.invoice_id=i.id AND service_id=:id GROUP BY i.id
			')
			->param(':id',$id)
			->execute();

		$service_invoices = array();
		foreach ($invoices as $item) {
			if ($bal = Invoice::balance($item['iid']) OR $paid) {
				$service_invoices[$item['iid']]['id'] = $item['iid'];
				$service_invoices[$item['iid']]['total'] = $bal;
				$service_invoices[$item['iid']]['due'] = $item['due'];
			}
		}

		return $service_invoices;
	}

	/**
	 * Return the total of amount outstanding for a service
	 *
	 * @param $id int Service ID
	 * @param $paid boolean Optionally only list the ones that are not paid.
	 * @return real Total amount outstanding
	 * @see Invoice::listservice()
	 */
	public static function servicetotal($id,$paid=TRUE) {
		$total = 0;

		foreach (Invoice::servicelist($id,$paid) as $item)
			$total += $item['total'];

		return $total;
	}

	/**
	 * Return the earliest due date of an outstanding invoice
	 *
	 * @param $id int Service ID
	 * @return datetime
	 */
	public static function servicedue($id) {
		$due = 0;

		foreach (Invoice::servicelist($id,FALSE) as $item)
			if ($due < $item['due'])
				$due = $item['due'];

		return $due;
	}

	public static function balance($id) {
		$invoice = ORM::factory('invoice')
			->where('id','=',$id)
			->find();

		// @todo We should call check() here to re-run the validation, which re-calcs the total
		// @todo might need to cache these results for performance
		#if ($invoice->loaded() AND $invoice->check())
		if ($invoice->loaded())
			return $invoice->total_amt-$invoice->billed_amt-$invoice->credit_amt;
		else
			return 0;
	}
}
?>