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

/**
 * This class provides invoice item capabilities.
 *
 * @package    Invoice
 * @category   Models
 * @author     Deon George
 * @copyright  (c) 2009-2013 Open Source Billing
 * @license    http://dev.osbill.net/license.html
 */
class Model_Invoice_Item extends ORM_OSB {
	// Relationships
	protected $_belongs_to = array(
		'invoice'=>array(),
		'service'=>array()
	);
	protected $_has_many = array(
		'tax'=>array('model'=>'Invoice_Item_Tax','far_key'=>'id')
	);

	protected $_display_filters = array(
		'date_orig'=>array(
			array('Config::date',array(':value')),
		),
		'date_start'=>array(
			array('Config::date',array(':value')),
		),
		'date_stop'=>array(
			array('Config::date',array(':value')),
		),
	);

	// Items belonging to an invoice item
	protected $_sub_items_load = array(
		'tax'=>FALSE,
	);

	// The total of all discounts
	public function discount() {
		return Currency::round($this->discount_amt);
	}

	/**
	 * The line that will be printed on an invoice
	 *
	 * @todo This method includes some database format validation routines, which can be removed when the database
	 *       is completly transformed.
	 */
	public function invoice_line() {
		$ii = NULL;

		// Our module is responsible for rending the invoice line
		$ii = ($this->module_id AND method_exists($this->module(),'invoice_item')) ? $this->module()->invoice_item($this->item_type) : StaticList_ItemType::get($this->item_type);

		switch ($this->item_type) {
			// Service Charges
			case 0:
			case 7:
				return ((! $this->service_id OR $this->product_id OR $this->charge_id OR $this->product_name OR ! $this->recurring_schedule OR ! $this->date_start OR ! $this->date_stop) ? '+ ' : '').$ii.' '.$this->period();

			case 1:
				// @todo
				return $ii;

			case 2:
			case 3:
			case 4:
			case 5:
			case 6:
				return ((! $this->service_id OR $this->product_id OR $this->charge_id OR $this->product_name OR $this->recurring_schedule OR ! $this->date_start OR ! $this->date_stop) ? '+ ' : '').$ii;
				
			case 124:
			case 125:
			case 126:
			case 127:
				// @todo
				return $ii;

			// @todo DB records to fix.
			default:
				if ($this->charge_id)
					return '*'.($ii ? $ii : $this->charge->description).' '.$this->period();
				else
					throw HTTP_Exception::factory(501,'Unable to render invoice item :id',array(':id'=>$this->id));
		}
	}

	/**
	 * Return an instance of the Model of this charge
	 */
	public function module() {
		$x = ORM::factory('Module',$this->module_id);

		if (! $x->loaded())
			throw new Kohana_Exception('Module :module doesnt exist?',array(':module'=>$this->module_id));

		return ORM::factory('Module',$this->module_id)->instance($this->module_ref);
	}

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

	public function save(Validation $validation = NULL) {
		// Our items will be clobbered once we save the object, so we need to save it here.
		$subitems = $this->subitems();

		// Save the invoice item
		parent::save($validation);

		// Need to save the associated items and their taxes
		if ($this->loaded()) {
			foreach ($subitems as $iito) {
				$iito->invoice_item_id = $this->id;

				if (! $iito->changed())
					continue;

				$iito->save();

				if (! $iito->saved()) {
					$this->void = 1;
					$this->save();

					break;
				}
			}

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

	/**
	 * Add tax to our item
	 *
	 * @param Model_Country the country to get the tax rates
	 * @param Boolean Is this price inc/ex tax
	 */
	public function subitem_add(Model_Country $co,$taxed=FALSE) {
		$orig = $this->subtotal();
		$tax = 0;

		foreach ($co->tax->find_all() as $to) {
			$iito = ORM::factory('Invoice_Item_Tax');

			$iito->tax_id = $to->id;
			$iito->amount = Currency::round($taxed ? ($orig-$orig/(1+$to->rate)) : $orig*$to->rate);

			$tax += $iito->amount;
			array_push($this->_sub_items,$iito);
		}

		// If taxed, we need to reduce our base_rate to a pre-tax amount
		if ($taxed) {
			$this->price_base -= Currency::round($tax/$this->quantity,1);

			// If there is any rounding, we'll take it off the last IITO
			$iito->amount += $orig-$this->total();
		}

		$this->_sub_items_sorted = FALSE;
	}

	// This total of this item before discounts and taxes
	public function subtotal($format=FALSE) {
		$result = $this->price_base*$this->quantity;

		return $format ? Currency::display($result) : $result;
	}

	// Sum up the tax that applies to this invoice item
	public function tax($format=FALSE) {
		$result = 0;

		foreach ($this->subitems() as $iito)
			$result += $iito->amount;

		return $format ? Currency::display($result) : Currency::round($result);
	}

	public function tax_items() {
		$result = array();

		foreach ($this->subitems() as $iito) {
			if (! isset($result[$iit->tax_id]))
				$result[$iit->tax_id] = 0;

			$result[$iito->tax_id] += $iito->amount;
		}

		return $result;
	}

	/**
	 * The title for invoice items
	 */
	public function title() {
		if ($this->service_id AND $this->module_id AND method_exists($this->module(),'invoice_title'))
			return $this->module_ref ? sprintf('%s: %s',$this->module()->invoice_title(),$this->service->name()) : $this->service->name();
		elseif ($x=$this->module() AND ($x instanceof Model_Charge) AND $x->product_id)
			return $x->product->title().' '.$this->service->name();
		elseif ($this->product_id)
			return sprintf('* %s: %s',$this->product->invoice_title(),$this->service->name());
		else
			return 'Unknown Item';
	}

	public function total($format=FALSE) {
		$result = $this->void ? 0 : $this->subtotal()+$this->tax()-$this->discount();

		return $format ? Currency::display($result) : Currency::round($result);
	}

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

	public function invoice_detail_items() {
		switch ($this->item_type) {
			case 0:
				return $this->service->details('invoice_detail_items');
			case 4:
				return array('Charge'=>_('Service Connection Fee'));
			case 5:
				return $this->charge->details('invoice_detail_items');
			default:
				return array('Item'=>$this->item_type);
		}
	}
}
?>