<?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 {
	// Relationships
	protected $_belongs_to = array(
		'invoice'=>array(),
		'module'=>array(),
		'product'=>array(),
		'service'=>array(),
	);

	protected $_has_many = array(
		'tax'=>array('model'=>'Invoice_Item_Tax','far_key'=>'id')
	);

	protected $_display_filters = array(
		'date_orig'=>array(
			array('Site::Date',array(':value')),
		),
		'date_start'=>array(
			array('Site::Date',array(':value')),
		),
		'date_stop'=>array(
			array('Site::Date',array(':value')),
		),
		'recurring_schedule'=>array(
			array('StaticList_RecurSchedule::get',array(':value')),
		),
	);

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

	/**
	 * Invoice Item Types
	 *
	 * @see isValid()
	 */
	private $_item_type = array(
		0=>'Product/Service',			// * Line Charge Topic on Invoice.
		1=>'Hardware',				// *
		2=>'Service Relocation Fee',		// * Must have corresponding SERVICE_ID
		3=>'Service Change',			// * Must have corresponding SERVICE_ID
		4=>'Service Connection',		// * Must have corresponding SERVICE_ID
		5=>'Excess Usage',			// * Excess Service Item, of item 0, must have corresponding SERVICE_ID
		6=>'Service Cancellation',		// * Must have corresponding SERVICE_ID
		7=>'Extra Product/Service Charge',	// * Service Billing in advance, Must have corresponding SERVICE_ID
		8=>'Product Addition',			// * Additional Product Customisation, Must have corresponding SERVICE_ID
		120=>'Credit/Debit Transfer',		// * SERVICE_ID is NULL, MODULE_ID is NULL, MODULE_REF is NULL : INVOICE_ID is NOT NULL
		124=>'Late Payment Fee',		// * SERVICE_ID is NULL, MODULE_ID = CHECKOUT MODULE, 
		125=>'Payment Fee',			// * SERVICE_ID is NULL, MODULE_ID = CHECKOUT MODULE, MODULE_REF = CHECKOUT NAME
		126=>'Other',				// * MODEL_ID should be a module
		127=>'Rounding',			// * SERVICE_ID is NULL, MODULE_ID is NULL, MODULE_REF is NULL
	);

	/** REQUIRED ABSTRACT METHODS **/

	/** LOCAL METHODS **/

	/**
	 * Module assocated with the invoice item
	 */
	private function _module() {
		if (! $this->module_id OR ! $this->module_ref)
			return NULL;

		return $this->module->instance($this->module_ref);
	}

	/**
	 * Return the list of available item types
	 */
	public function _types() {
		return $this->_item_type;
	}

	/**
	 * 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 add_sub_item(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;
			$this->subitem_add($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();
		}
	}

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

	/**
	 * Validate that this record is correct
	 */
	private function isValid() {
		switch ($this->item_type) {
			case 0:
				// @todo Validate if module_id = charge and module_ref corresponds with the line item
                                if (! $this->service_id OR ! $this->product_id OR ($this->module_id AND $this->module_id != 30 AND ! is_null($this>module_ref)) OR $this->product_name OR is_null($this->recurring_schedule))
                                        return FALSE;
				break;
			case 1:
                                if (! $this->product_id OR $this->module_id OR $this->module_ref OR $this->product_name OR ! is_null($this->recurring_schedule))
                                        return FALSE;
				break;
			// These items come from the charge module, so we should have a charge module_id and ref
			case 2:
                                if (! $this->service_id OR ! $this->product_id OR ($this->module_id AND $this->module_id != 30 AND ! is_null($this>module_ref)) OR $this->product_name OR ! is_null($this->recurring_schedule))
                                        return FALSE;
				break;
			case 3:
			case 4:
			case 7:
                                if (! $this->service_id OR ! $this->product_id OR ! $this->module_id OR ! $this->module_ref OR $this->product_name OR ! is_null($this->recurring_schedule))
                                        return FALSE;
				break;
			// These items come from the charge module, so we should have a charge module_id and ref
			case 5:
                                if (! $this->service_id OR ! $this->product_id OR ! $this->module_id OR ! $this->module_ref OR $this->product_name OR ! is_null($this->recurring_schedule))
                                        return FALSE;
				break;
			case 124:
                                if ($this->service_id OR $this->product_id OR $this->module_id OR $this->module_ref OR $this->product_name OR ! is_null($this->recurring_schedule))
                                        return FALSE;
				break;
		}

		// If we get here, assume it is valid
		return TRUE;
	}

	/**
	 * Return an instance of the Model of this charge
	 */
	public function module() {
		return $this->_module();
	}

	public function name($variable=NULL) {
		if (! $this->isValid())
			return sprintf('Record Error [%s-%s]',$this->item_type,$this->id);

		if (is_null($variable) OR ! $variable instanceof Model_Language)
			$variable = Site::language();

		switch ($this->item_type) {
			case 0:
			case 2:
			case 3:
			case 4:
			case 5:
				return sprintf('%s: %s',$this->product->name($variable),$this->service->namesub($variable));
			case 124:
				return StaticList_ItemType::get($this->item_type);
			default:
				return sprintf('Unknown [%s-%s]',$this->item_type,$this->id);
		}
	}

	public function namesub($variable=NULL) {
		if (! $this->isValid())
			return sprintf('Record Error [%s-%s]',$this->item_type,$this->id);

		switch ($this->item_type) {
			case 0:
				return sprintf('%s: %s',StaticList_ItemType::get($this->item_type),$this->period());
			case 2:
				return sprintf('%s: %s',StaticList_ItemType::get($this->item_type),$this->_module() ? $this->_module()->display('date_charge') : $this->period());
			case 3:
			case 4:
			case 6:
				return sprintf('%s: %s',StaticList_ItemType::get($this->item_type),($this->_module()->attributes ? $this->_module()->namesub($variable) : $this->_module()->display('date_charge')));
			case 5:
			case 7:
				return $this->_module()->namesub($variable);
			default:
				return sprintf('Unknown [%s-%s]',$this->item_type,$this->id);
		}
	}

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

	/**
	 * Display the Invoice Item Reference Number
	 */
	public function refnum($short=FALSE) {
		return $short ? '' : sprintf('%03s-',$this->item_type).sprintf('%06s',$this->id);
	}

	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->active = 0;
					$this->save();

					break;
				}
			}

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

		return $this;
	}

	// 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[$iito->tax_id]))
				$result[$iito->tax_id] = 0;

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

		return $result;
	}

	public function title(Model_Language $lo) {
		if (! $this->isValid())
			return 'Record Error';

		switch ($this->item_type) {
			case 0:
			case 2:
			case 3:
			case 4:
				return $this->product->name($lo);
			case 5:
				return $this->_module()->name($lo);
			case 124:
				return StaticList_ItemType::get($this->item_type);
			default:
				return 'Unknown';
		}
	}

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

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