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

/**
 * This class provides invoice item capabilities.
 *
 * @package    OSB
 * @subpackage Invoice
 * @category   Models
 * @author     Deon George
 * @copyright  (c) 2010 Open Source Billing
 * @license    http://dev.osbill.net/license.html
 */
class Model_Invoice_Item extends ORMOSB {
	protected $_belongs_to = array(
		'product'=>array(),
		'invoice'=>array(),
		'service'=>array()
	);
	protected $_has_many = array(
		'invoice_item_tax'=>array('far_key'=>'id')
	);
	protected $_updated_column = FALSE; // @todo No update columns

	// Display a transaction number
	public function trannum() {
		return sprintf('%03s-%06s',$this->item_type,$this->id);
	}

	// Display the period that a transaction applies
	public function period() {
		if ($this->date_start == $this->date_stop)
			return sprintf('%s: %s',_('Date'),Config::date($this->date_start));

		else
			return sprintf('%s: %s -> %s',_('Period'),Config::date($this->date_start),Config::date($this->date_stop));
	}

	/**
	 * On invoices where there are multiple charges for the same item
	 * (eg spanning the next invoice period), this should show the period
	 * range for the additional sub-items.
	 */
	public function invoice_display() {
		return $this->period();
	}

	public function subtotal() {
		return ($this->price_base+$this->price_setup)*$this->quantity;
	}

	public function total() {
		return ($this->price_base+$this->price_setup)*$this->quantity+$this->tax_amt-$this->discount_amt;
	}

	public function save(Validation $validation = NULL) {
		// Save the invoice item
		parent::save();

		// Need to save the taxes and discounts associated with the invoice_item
		if ($this->saved()) {
			$invoice_item_tax = ORM::factory('invoice_item_tax');
			$tax_total = 0;

			// Save TAX details
			// @todo tax parameters should come from user session
			foreach (Tax::detail(61,NULL,$this->subtotal()) as $tax) {
				$invoice_item_tax->clear();
				$invoice_item_tax->invoice_item_id = $this->id;
				// @todo Rounding here should come from a global config
				$tax_total += ($invoice_item_tax->amount = round($tax['amount'],2));
				$invoice_item_tax->tax_id = $tax['id'];

				if (! $invoice_item_tax->check())
					throw new Kohana_Exception('Couldnt save tax for some reason - failed check()?');

				$invoice_item_tax->save();

				if (! $invoice_item_tax->saved())
					throw new Kohana_Exception('Couldnt save tax for some reason - failed save()?');
			}

			// Save DISCOUNT details
			// @todo calculate discounts

			$this->tax_amt = $tax_total;
			$this->total_amt = $this->total();
			parent::save();

		} else
			throw new Kohana_Exception('Couldnt save invoice_item for some reason?');
	}
}
?>