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

/**
 * This class provides invoice 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 extends ORM 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'),
		'invoice_memo'=>array('far_key'=>'id'),
		'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('Site::Date',array(':value')),
		),
		'due_date'=>array(
			array('Site::Date',array(':value')),
		),
		'status'=>array(
			array('StaticList_YesNo::get',array(':value',TRUE)),
		),
		'void'=>array(
			array('StaticList_YesNo::get',array(':value',TRUE)),
		),
	);

	// Items belonging to an invoice
	protected $_sub_items_load = array(
		'invoice_item'=>array('service_id','product_id','item_type','date_start','date_stop'),
	);

	protected $_compress_column = array(
		'reminders',
	);

	private $_render = array();

	/** REQUIRED ABSTRACT METHODS **/

	/** REQUIRED INTERFACE METHODS **/

	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));
	}

	/** LOCAL METHODS **/

	/**
	 * Add items to the invoice while building it
	 */
	public function add_sub_item(Model_Invoice_Item $iio,$taxed=FALSE) {
		$iio->add_sub_item($this->account->country,$taxed);

		$this->subitem_add($iio);
	}

	/**
	 * 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 = $this->status ? Currency::round($this->total()-$this->payments_total(),1) : 0;

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

	public function email() {
		return ORM::factory('Email_Log')
			->where('module_id','=',$this->mid())
			->where('module_data','=',$this);
	}

	/**
	 * Return an array of items to render, in appropriate order
	 */
	public function items_render() {
		$result = $track = array();

		// If the invoice hasnt been saved, then we'll need to assign some fake IDs to the items
		$c = 0;
		if (! $this->_loaded)
			foreach ($this->_sub_items as $iio)
				$iio->id = '****:'.$c++;

		// First work through our recurring schedule items
		$result['s'] = array();
		foreach ($this->recur_schedules() as $rs)
			foreach ($this->recur_schedule_services($rs) as $sid)
				foreach ($this->service_products($sid) as $pid) {
					// Get all the services with this recur schedule first, then get service charges with rs=NULL
					foreach ($this->_sub_items as $iio) {

						// If this is not the recur schedule or service we are working with, skip it
						if ($iio->service_id != $sid OR $iio->product_id != $pid OR $iio->recurring_schedule != $rs OR in_array($iio->id,$track))
							continue;

						// Ensure we dont process this item again
						array_push($track,$iio->id);

						if (! $iio->void)
							array_push($result['s'],$iio);
					}

					// Get all the items for this service with a NULL rs
					foreach ($this->_sub_items as $iio) {
						// If this is not the recur schedule or service we are working with, skip it
						if ($iio->service_id != $sid OR $iio->product_id != $pid OR ! is_null($iio->recurring_schedule) OR in_array($iio->id,$track))
							continue;

						// Ensure we dont process this item again
						array_push($track,$iio->id);

						if (! $iio->void)
							array_push($result['s'],$iio);
					}
				}

		// Get service items that dont have a recurring schedule
		foreach ($this->_sub_items as $iio)
			if (! $iio->void AND ! in_array($iio->id,$track) AND $iio->service_id) {
				// Ensure we dont process this item again
				array_push($track,$iio->id);

				array_push($result['s'],$iio);
			}

		// Next get the items we havent already got
		$result['other'] = array();
		foreach ($this->_sub_items as $iio)
			if (! $iio->void AND ! in_array($iio->id,$track))
				array_push($result['other'],$iio);

		// Debug
		#foreach ($result['s'] as $iio)
		#	echo Debug::vars(array('s'=>$iio->object()));
		#foreach ($result['other'] as $iio)
		#	echo Debug::vars(array('o'=>$iio->object()));

		return $result;
	}

	/**
	 * Return a summary of all itemss on an invoice
	 */
	public function items_summary() {
		$result = array();
		$lo = $this->account->language;

		$track['p'] = $track = array();
		foreach ($this->items_render() as $key => $items) {
			switch ($key) {
				case 's':
					$last = '';
					foreach ($items as $iio) {

						if ($iio->product) {
							$p = $iio->title($lo);
						}

						if (! isset($result[$p])) {
							$result[$p]['quantity'] = 0;
							$result[$p]['subtotal'] = 0;
						}

						$result[$p]['quantity']++;
						$result[$p]['subtotal'] += $iio->subtotal();
					}

					break;

				case 'other':
					break;
			}
		}

		ksort($result);
		return $result;
	}

	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) : $result;
	}

	/**
	 * For a particular recurring schedule, get al lthe services
	 */
	private function recur_schedule_services($rs) {
		$result = array();

		if (! $rs)
			return $result;

		foreach ($this->_sub_items as $o)
			if ($o->service_id AND $o->recurring_schedule == $rs AND ! in_array($o->service_id,$result))
				array_push($result,$o->service_id);

		return $result;
	}

	/**
	 * Get the recurring schedules on an invoice
	 * Exclude any NULL recurring schedules
	 */
	private function recur_schedules() {
		$result = array();

		foreach ($this->_sub_items as $o)
			if (! is_null($o->recurring_schedule) AND ! in_array($o->recurring_schedule,$result))
				array_push($result,$o->recurring_schedule);

		sort($result);

		return $result;
	}

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

	/**
	 * Check the reminder value
	 */
	public function remind($key) {
		if (isset($this->reminders[$key])) {
			$x = $this->reminders[$key];
			return is_array($x) ? end($x) : $x;
		} else
			return FALSE;
	}

	/**
	 * Returns the array of Email Template Objects
	 */
	public function reminders($key=NULL,$format=FALSE) {
		if (is_null($key) AND ! $this->reminders)
			return array();

		$prefix = 'task_invoice_';

		if (is_null($key)) {
			$result = array();

			foreach ($this->reminders as $k=>$v)
				array_push($result,ORM::factory('Email_Template',array('name'=>$prefix.$k)));

			return $result;

		} else {
			$key = preg_replace("/^$prefix/",'',$key);

			return isset($this->reminders[$key]) ? ($format ? Config::date($this->reminders[$key]) : $this->reminders[$key]) : NULL;
		}
	}

	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();

		// If this is a new invoice, we'll need to do more work
		$new = ! $this->loaded();

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

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

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

				$iio->save();

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

					break;
				}

				// If this is a new invoice, we'll need to update some other items
				if ($new) {
					// Update next invoice date
					if ($iio->item_type == 0) {
						$iio->service->date_next_invoice = $iio->date_stop+86400;

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

					// Update charge iteme
					if (($x=$iio->module()) AND ($x instanceof Model_Charge)) {
						$x->processed = 1;

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

				// @todo Need to save discount information
			}


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

		return $this;
	}

	/**
	 * For a particular service, get all the products
	 */
	private function service_products($sid) {
		$result = array();

		foreach ($this->_sub_items as $o)
			if ($o->product_id AND $o->service_id == $sid AND ! in_array($o->product_id,$result))
				array_push($result,$o->product_id);

		return $result;
	}

	public function service_products_total($sid,$pid,$format=FALSE) {
		$result = 0;

		foreach ($this->_sub_items as $o)
			if ($o->service_id == $sid AND $o->product_id == $pid)
				$result += $o->total();

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

	public function set_remind($key,$value,$add=FALSE) {
		$x = $this->reminders;

		// If our value is null, we'll remove it.
		if (is_null($value) AND isset($x[$key]))
			unset($x[$key]);

		elseif ($add) {
			if (! is_array($a=$x[$key]))
				$x[$key] = array($a);

			$x[$key][] = $value;

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

		$this->reminders = $x;
		$this->save();

		return $this->saved();
	}

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

		foreach ($this->_sub_items as $iio) {
			// Ignore voided items
			if ($iio->void)
				continue;

			$return = FALSE;

			switch ($type) {
				case 'CHARGE':
					if ($iio->quantity > 0)
						$return = TRUE;
					break;

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

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

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

		return $result;
	}

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

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

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

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

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

		return $format ? Currency::display($result) : $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->subitems() as $iio) {
			foreach ($iio->tax->find_all() as $iito) {
				if (! isset($summary[$iito->tax_id]))
					$summary[$iito->tax_id] = $iito->amount;
				else
					$summary[$iito->tax_id] += $iito->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;

		// This will include charges and credits
		foreach ($this->subitems() as $ito)
			$result += $ito->total();

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

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

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

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

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

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

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

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

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

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

	// Our list function

	/**
	 * Search for invoices matching a term
	 */
	public function list_autocomplete($term,$index,$value,array $label,array $limit=array(),array $options=array()) {
		// We only show invoice numbers.
		if (! is_numeric($term))
			return array();

		$ao = Auth::instance()->get_user();

		$this->clear();
		$this->where_active();

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

		// Restrict results to authorised accounts
		array_push($limit,array('account_id','IN',$ao->RTM->customers($ao->RTM)));

		return parent::list_autocomplete($term,$index,$value,$label,$limit,$options);
	}

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

		if ($authorised)
			$this->where_authorised();

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

		return $result;
	}

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

		foreach ($this->_list_due($authorised) as $io)
			if (is_null($time) OR $io->due_date > $time)
				array_push($result,$io);

		return $result;
	}

	public function list_due_total($format=FALSE,$time=NULL,$authorised=TRUE) {
		$result = 0;

		foreach ($this->list_due($time,$authorised) as $io)
			$result += $io->due();

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

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

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

		foreach ($this->_list_due($authorised) 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,$authorised=TRUE) {
		$result = array();

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

					break;
				}
		}

		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();
	}
}
?>