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

/**
 * This class provides invoice 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 extends ORM_OSB implements Cartable {
	protected $_belongs_to = array(
		'account'=>array()
	);
	protected $_has_many = array(
		'invoice_item'=>array('far_key'=>'id'),
		'invoice_item_tax'=>array('through'=>'invoice_item'),
		'service'=>array('through'=>'invoice_item'),
		'payment'=>array('through'=>'payment_item'),
		'payment_item'=>array('far_key'=>'id'),
	);

	protected $_sorting = array(
		'id'=>'DESC',
	);

	protected $_display_filters = array(
		'date_orig'=>array(
			array('Config::date',array(':value')),
		),
		'due_date'=>array(
			array('Config::date',array(':value')),
		),
		'billed_amt'=>array(
			array('Currency::display',array(':value')),
		),
		'credit_amt'=>array(
			array('Currency::display',array(':value')),
		),
		'status'=>array(
			array('StaticList_YesNo::display',array(':value')),
		),
		'total_amt'=>array(
			array('Currency::display',array(':value')),
		),
	);

	// Items belonging to an invoice
	private $invoice_items = array();

	/** INTERFACE REQUIREMENTS **/
	public function cart_item() {
		return new Cart_Item(1,sprintf('Invoice: %s',$this->refnum()),$this->due());
	}

	/**
	 * Return if this invoice is already in the cart
	 */
	public function cart_exists() {
		return count(Cart::instance()->get($this->mid(),$this->id));
	}

	public function __construct($id = NULL) {
		// Load our Model
		parent::__construct($id);

		// Autoload our Sub Items
		if ($this->loaded())
			$this->_load_sub_items();

		return $this;
	}

	/**
	 * Load our invoice items
	 * We need these so that we can calculate totals, etc
	 */
	private function _load_sub_items() {
		// Load our sub items
		$this->invoice_items = $this->invoice_item->find_all()->as_array();
	}

	/**
	 * Add an item to an invoice
	 */
	public function add_item() {
		if ($this->loaded() and ! $this->invoice_items)
			throw new Kohana_Exception('Need to load invoice_items?');

		$c = count($this->invoice_items);

		$this->invoice_items[$c] = ORM::factory('Invoice_Item');

		return $this->invoice_items[$c];
	}

	/**
	 * Return a list of valid checkout options for this invoice
	 */
	public function checkout() {
		$due = $this->due();

		return ORM::factory('Checkout')
			->where_active()
			->where('amount_min','<=',$due)
			->where_open()
			->and_where('amount_max','>=',$due)
			->or_where('amount_max','is',null)
			->where_close()->find_all();
	}

	/**
	 * Display the amount due
	 */
	public function due($format=FALSE) {
		// If the invoice is active calculate the due amount
		$result = $this->status ? $this->total()-$this->payments_total() : 0;

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

	/**
	 * Display the Invoice Number
	 */
	public function id() {
		return sprintf('%06s',$this->id);
	}

	/**
	 * Return a list of invoice items for this payment.
	 * @param type [CHARGE|CREDIT|ALL]
	 * @see invoice_items
	 */
	public function items($type='ALL') {
		$result = array();

		foreach ($this->invoice_items as $ito) {
			$return = FALSE;
			switch ($type) {
				case 'CHARGE':
					if ($ito->quantity > 0)
						$return = TRUE;
					break;

				case 'CREDIT':
					if ($ito->quantity < 0)
						$return = TRUE;
					break;

				case 'ALL':
				default:
					$return = TRUE;
					break;

			}

			if ($return)
				array_push($result,$ito);
		}

		return $result;
	}

	/**
	 * Provide a sorted list of items by an index
	 */
	public function items_index($index) {
		static $result = array();

		// We'll return a cached result for quicker processing
		if (! $this->_changed AND array_key_exists($index,$result))
			return $result[$index];

		foreach ($this->items() as $ito) {
			switch ($index) {
				case 'account':
					if (! $ito->service_id)
						$result[$index][$ito->id] = $ito;

					break;

				case 'period':
					// We only show the services in this period
					if (! is_null($ito->recurring_schedule) AND (empty($result[$index][$ito->recurring_schedule]) OR ! in_array($ito->service_id,$result[$index][$ito->recurring_schedule])))
						$result[$index][$ito->recurring_schedule][] = $ito->service_id;

					break;

				case 'service':
				default:
					if ($ito->service_id)
						$result[$index][$ito->service_id][] = $ito;

					break;
			}
		}

		return array_key_exists($index,$result) ? $result[$index] : array();
	}

	/**
	 * Get a list of invoice_items for a service_id on an invoice
	 *
	 * We use this to list details by service on an invoice.
	 */
// @todo to retire
	public function items_services(array $items=array()) {
		$result = array();
		if (! $items)
			$items = $this->items();

		foreach ($items as $ito)
			if ($ito->service_id AND empty($result[$ito->service_id]))
				$result[$ito->service_id] = $ito;

		return $result;
	}

// @todo to retire
	public function items_invoice() {
		$result = array();
		$items = $this->items();

		foreach ($items as $ito)
			if (! $ito->service_id AND empty($result[$ito->id]))
				$result[$ito->id] = $ito;

		return $result;
	}

	/**
	 * Return all invoice items for a specific service
	 */
	public function items_service($service_id) {
		$svs = $this->items_index('service');

		if (array_key_exists($service_id,$svs)) {
			Sort::MAsort($svs[$service_id],'item_type');

			return $svs[$service_id];
		} else
			return array();
	}

// @todo to retire
	/**
	 * Return a list of periods and services
	 *
	 * This is so that we can list items summarised by billing period
	 */
	public function items_service_periods() {
		$result = array();

		$c = array();
		foreach ($this->items() as $ito)
			if ($ito->service_id) {
				// If we have already covered a service with no recurring_schedule
				if (! $ito->recurring_schedule AND in_array($ito->service_id,$c))
					continue;

				array_push($c,$ito->service_id);

				$result[$ito->recurring_schedule][] = $ito;
			}

		return $result;
	}

	/**
	 * Summarise the items on an invoice
	 *
	 * We summaries based on product.
	 */
// @todo
	public function items_summary() {
		$result = array();

		foreach ($this->items() as $ito) {
			// We only summarise item_type=0
			if (! $ito->item_type == 0)
				continue;

			$t = $ito->product->name();

			if (! isset($result[$t])) {
				$result[$t]['quantity'] = 0;
				$result[$t]['subtotal'] = 0;
			}

			$result[$t]['quantity'] += $ito->quantity;
			$result[$t]['subtotal'] += $ito->subtotal();
		}

		return $result;
	}

	/**
	 * Calculate the total for items for a service
	 */
	public function items_service_total($sid) {
		$total = 0;

		foreach ($this->items_service($sid) as $ito)
			$total += $ito->total();

		return $total;
	}

	/**
	 * Calculate the tax of items for a service
	 */
	public function items_service_tax($sid) {
		$total = 0;

		foreach ($this->items_service($sid) as $ito)
			$total += $ito->tax();

		return $total;
	}

	/**
	 * Calculate the discounts of items for a service
	 */
	public function items_service_discount($sid) {
		$total = 0;

		foreach ($this->items_service($sid) as $ito)
			$total += $ito->discount();

		return $total;
	}

	public function min_due($date) {
		return strtotime(date('Y-M-d',($date < time()) ? time()+ORM::factory('Invoice')->config('DUE_DAYS_MIN')*86400 : $date));
	}

	/**
	 * Display the Invoice Reference Number
	 */
	public function refnum() {
		return sprintf('%s-%06s',$this->account->accnum(),$this->id);
	}

	public function payments() {
		return $this->payment_item->find_all();
	}

	public function payments_total($format=FALSE) {
		$result = 0;

		foreach ($this->payments() as $po)
			$result += $po->alloc_amt;

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

	/**
	 * Check the reminder value
	 */
	public function remind($key) {
		if (! $this->loaded())
			return NULL;

		if (! trim($this->reminders))
			return FALSE;

		if (! preg_match('/^a:/',$this->reminders))
			throw new Kohana_Exception('Reminder is not an array? (:reminder)',array(':remind',$this->reminders));

		$remind = unserialize($this->reminders);

		if (isset($remind[$key]))
			return (is_array($remind[$key])) ? end($remind[$key]) : $remind[$key];
		else
			return FALSE;
	}

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

		// Save the invoice
		if ($this->changed())
			parent::save($validation);

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

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

				if (! $iio->check()) {
					// @todo Mark invoice as cancelled and write a memo, then...
					throw new Kohana_Exception('Problem saving invoice_item for invoice :invoice - Failed check()',array(':invoice'=>$this->id));
				}

				$iio->save();

				if (! $iio->saved()) {
					// @todo Mark invoice as cancelled and write a memo, then...
					throw new Kohana_Exception('Problem saving invoice_item for invoice :invoice - Failed save()',array(':invoice'=>$this->id));
				}

				// @todo Need to save discount information
			}


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

		return TRUE;
	}

	public function set_remind($key,$value,$add=FALSE) {
		if (! $this->loaded())
			throw new Kohana_Exception('Cant call :method when a record not loaded.',array(':method',__METHOD__));

		if (! trim($this->reminders)) {
			$remind = array();

		} else {
			if (! preg_match('/^a:/',$this->reminders))
				throw new Kohana_Exception('Reminder is not an array? (:reminder)',array(':remind',$this->reminders));

			$remind = unserialize($this->reminders);
		}

		// If our value is null, we'll remove it.
		if (is_null($value) AND isset($remind[$key]))
			unset($remind[$key]);
		elseif ($add) {
			if (! is_array($a=$remind[$key]))
				$remind[$key] = array($a);

			$remind[$key][] = $value;

		} else
			$remind[$key] = $value;

		$this->reminders = serialize($remind);
		$this->save();
		return $this->saved();
	}

	/**
	 * Return a list of affiliates associated with this invoice (via the service)
	 */
	public function service_affiliates() {
		$return = array();

		foreach ($this->items() as $io)
			array_push($return,$io->service->affiliate_id);

		return $return;
	}

	/**
	 * Return the subtotal of all items
	 */
	public function subtotal($format=FALSE) {
		$result = 0;

		foreach ($this->items() as $ito)
			$result += $ito->subtotal();

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

	public function tax($format=FALSE) {
		$result = 0;

		foreach ($this->items() as $ito)
			$result += $ito->tax();

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

	/**
	 * Return a list of taxes used on this invoice
	 * @todo Move some of this to invoice_item_tax.
	 */
	public function tax_summary() {
		$summary = array();

		foreach ($this->items() as $ito) {
			foreach ($ito->invoice_item_tax->find_all() as $item_tax) {
				if (! isset($summary[$item_tax->tax_id]))
					$summary[$item_tax->tax_id] = $item_tax->amount;
				else
					$summary[$item_tax->tax_id] += $item_tax->amount;
			}
		}

		// @todo This should be removed eventually
		if (! $summary)
			$summary[1] = $this->tax();

		return $summary;
	}

	/**
	 * Return the total of all items
	 */
	public function total($format=FALSE) {
		$result = 0;

		// @todo - This should be required, but during checkout payment processing $pio->invoice->total() showed no invoice items?
		if ($this->loaded() AND ! count($this->items()))
			$this->_load_sub_items();

		foreach ($this->items() as $ito)
			$result += $ito->total();

		// Reduce by any credits
		$result -= $this->credit_amt;

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

	public function total_charges($format=FALSE) {
		$result = 0;

		foreach ($this->items('CHARGE') as $ito)
			$result += $ito->subtotal()+$ito->tax();

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

	public function total_credits($format=FALSE) {
		$result = 0;

		// @todo Remove when credit_amt is dropped.
		if ($this->credit_amt)
			$result = $this->credit_amt;

		foreach ($this->items('CREDIT') as $ito)
			$result += ($ito->subtotal()+$ito->tax())*-1;

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

	public function total_discount($format=FALSE) {
		$result = 0;

		foreach ($this->items() as $ito)
			$result += $ito->discount();

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

	/** LIST FUNCTIONS **/

	/**
	 * Search for invoices matching a term
	 */
	public function list_autocomplete($term,$index='id') {
		$return = array();

		if (is_numeric($term)) {
			$this->clear();
			$value = 'account->name(TRUE)';

			// Build our where clause
			$this->where('id','like','%'.$term.'%');

			// @todo This should limit the results so that users dont see other users services.
			foreach ($this->find_all() as $o)
				$return[$o->$index] = array(
					'value'=>$o->$index,
					'label'=>sprintf('INV %s: %s',$o->id,Table::resolve($o,$value)),
				);
		}

		return $return;
	}

	private function _list_due() {
		static $result = array();

		if (! $result)
			foreach ($this->_where_active()->_where_unprocessed()->find_all() as $io)
				if ($io->due())
					array_push($result,$io);

		return $result;
	}

	private function _where_unprocessed() {
		return $this->where_open()->where('process_status','!=',1)->or_where('process_status','is',NULL)->where_close();
	}

	public function where_unprocessed() {
		return $this->_where_unprocessed();
	}

	/**
	 * Identify all the invoices that are due
	 */
	public function list_overdue($time=NULL) {
		$result = array();

		if (is_null($time))
			$time = time();

		foreach ($this->_list_due() as $io)
			if ($io->due_date <= $time)
				array_push($result,$io);

		return $result;
	}

	/**
	 * Return a list of invoices that are over their due date with/without auto billing
	 */
	public function list_overdue_billing($time=NULL,$billing=FALSE) {
		$return = array();

		foreach ($this->list_overdue($time) as $io) {
			$i = FALSE;
			foreach ($io->service->find_all() as $so)
				if (($billing AND $so->account_billing_id) OR (! $billing AND ! $so->account_billing_id)) {
					array_push($return,$io);

					break;
				}
		}

		return $return;
	}

	/**
	 * Return a list of invoices that are due, excluding overdue.
	 */
	public function list_due($time=NULL) {
		$result = array();

		foreach ($this->_list_due() as $io)
			if ($io->due_date > time())
				if (is_null($time))
					array_push($result,$io);
				elseif ($io->due_date <= $time)
					array_push($result,$io);

		return $result;
	}

	/**
	 * Return a list of invoices that need to be sent.
	 * @todo This should be optimised a little to return only invoices to send, instead of looking for them.
	 */
	public function list_tosend() {
		return ORM::factory('Invoice')->where_active()->where_open()->where('print_status','is',NULL)->or_where('print_status','!=',1)->where_close();
	}

	public function html() {
		// @todo This should be in a config file.
		$css = '<style type="text/css">';
		$css .= 'table.box-left { border: 1px solid #AAAACC; margin-right: auto; }';
		$css .= 'tr.head { font-weight: bold; }';
		$css .= 'td.head { font-weight: bold; }';
		$css .= 'td.right { text-align: right; }';
		$css .= 'tr.odd { background-color: #FCFCFE; }';
		$css .= 'tr.even { background-color: #F6F6F8; }';
		$css .= '</style>';

		$output = View::factory('invoice/user/email')
			->set('mediapath',Route::get('default/media'))
			->set('io',$this);

		return $css.$output;
	}
}
?>