<?php
/*------------------------------------------------------------------------------
  $Id$

  AbanteCart, Ideal OpenSource Ecommerce Solution
  http://www.AbanteCart.com

  Copyright © 2011-2014 Belavier Commerce LLC

  This source file is subject to Open Software License (OSL 3.0)
  License details is bundled with this package in the file LICENSE.txt.
  It is also available at this URL:
  <http://www.opensource.org/licenses/OSL-3.0>

 UPGRADE NOTE:
   Do not edit or add to this file if you wish to upgrade AbanteCart to newer
   versions in the future. If you wish to customize AbanteCart for your
   needs please refer to http://www.AbanteCart.com for more information.
------------------------------------------------------------------------------*/
if (! defined ( 'DIR_CORE' )) {
	header ( 'Location: static_pages/' );
}
/**
 * Class ATax
 */
final class ATax {
	private $taxes = array();
	/**
	 * @var Registry
	 */
	private $registry;
	/**
	 * @var AConfig
	 */
	private $config;
	/**
	 * @var ACache
	 */
	private $cache;
	/**
	 * @var ADB
	 */
	private $db;
	/**
	 * @var ASession
	 */
	private $session;

	/**
	 * @param $registry Registry
	 */
	public function __construct($registry) {
		$this->registry = $registry;
		$this->config = $registry->get('config');
		$this->db = $registry->get('db');	
		$this->session = $registry->get('session');
		$this->cache = $registry->get('cache');

		if (isset($this->session->data['country_id']) && isset($this->session->data['zone_id'])) {
			$country_id = $this->session->data['country_id'];
	 		$zone_id = $this->session->data['zone_id'];
		} else {
			if($this->config->get('config_tax_store')){
				$country_id = $this->config->get('config_country_id');
				$zone_id = $this->config->get('config_zone_id');
			}else{
				$country_id = $zone_id = 0;
			}
		}
		$this->setZone($country_id, $zone_id);
  	}

	/**
	 * Set tax country ID and zone ID for the session
	 * Also it loads available taxes for the zone
	 * @param int $country_id
	 * @param int $zone_id
	 */
	public function setZone($country_id, $zone_id) {
		$country_id = (int)$country_id;
		$zone_id = (int)$zone_id;
		$results = $this->getTaxes($country_id, $zone_id);
		$this->taxes = array();
		foreach ($results as $result) {
      		$this->taxes[$result['tax_class_id']][] = array(
        		'rate'        => $result['rate'],
				'rate_prefix'    => $result['rate_prefix'],
				'threshold_condition'    => $result['threshold_condition'],
				'threshold'    => $result['threshold'],
        		'description' => $result['description'],
				'priority'    => $result['priority']
      		);
    	}

		$this->session->data['country_id'] = $country_id;
		$this->session->data['zone_id'] = $zone_id;
	}

	/**
	 * Get available tax classes for country ID and zone ID
	 * Storefront use only!!!
	 * @param $country_id
	 * @param $zone_id
	 * @return mixed|null
	 */

	public function getTaxes($country_id, $zone_id){
		$country_id = (int)$country_id;
		$zone_id = (int)$zone_id;
		
		$language = $this->registry->get('language');
		$language_id = $language->getLanguageID();
		
		$cache_name = 'tax_class.'.$country_id.'.'.$zone_id;
		$results = $this->cache->get($cache_name, $language_id);

		if(is_null($results)){
			//Note: Default language text is picked up if no selected language available
			$sql = "SELECT tr.tax_class_id,
							tr.rate AS rate, tr.rate_prefix AS rate_prefix, 
							tr.threshold_condition AS threshold_condition, tr.threshold AS threshold,
							COALESCE( td1.title,td2.title) as title,
							COALESCE( NULLIF(trd1.description, ''),
									  NULLIF(td1.description, ''),
									  NULLIF(trd2.description, ''),
									  NULLIF(td2.description, ''),
									  COALESCE( td1.title,td2.title)
							) as description,
							tr.priority	
					FROM " . $this->db->table("tax_rates") . " tr
					LEFT JOIN " . $this->db->table("tax_rate_descriptions") . " trd1 ON 
						(tr.tax_rate_id = trd1.tax_rate_id AND trd1.language_id = '" . (int)$language_id . "')
					LEFT JOIN " . $this->db->table("tax_rate_descriptions") . " trd2 ON 
						(tr.tax_rate_id = trd2.tax_rate_id AND trd2.language_id = '" . (int)$default_lang_id . "')
					LEFT JOIN " . $this->db->table("tax_classes") . " tc ON tc.tax_class_id = tr.tax_class_id
					LEFT JOIN " . $this->db->table("tax_class_descriptions") . " td1 ON 
						(tc.tax_class_id = td1.tax_class_id AND td1.language_id = '" . (int)$language_id . "')
					LEFT JOIN " . $this->db->table("tax_class_descriptions") . " td2 ON 
						(tc.tax_class_id = td2.tax_class_id AND td2.language_id = '" . (int)$default_lang_id . "')
					WHERE (tr.zone_id = '0' OR tr.zone_id = '" . $zone_id . "')
						AND tr.location_id in (SELECT z2l.location_id
											   FROM " . $this->db->table("zones_to_locations") . " z2l, " . $this->db->table("locations") . " l
											   WHERE z2l.location_id = l.location_id and z2l.zone_id = '" . $zone_id . "')
					ORDER BY tr.priority ASC";
			$tax_rate_query = $this->db->query( $sql );
			$results = $tax_rate_query->rows;
			$this->cache->set($cache_name,$results, $language_id);
		}

		return $results;
	}
	
	/**
	* Add Calculated tax based on provided $tax_class_id
	* If $calculate switch passed as false skip tax calculation. 
	* This is used in display of product price with tax added or not (based on config_tax )
	* @param float $value
 	* @param int $tax_class_id
 	* @param bool $calculate
 	* @return float
	*/
	public function calculate($value, $tax_class_id, $calculate = TRUE) {
		if (($calculate) && (isset($this->taxes[$tax_class_id])))  {
      		return $value + $this->calcTotalTaxAmount($value, $tax_class_id);
    	} else {
    		//skip culculation
      		return $value;
    	}
  	}
        
	/**
	 * Calculate total applicable tax amount based on the amount provided
	 * @param float $amount
	 * @param int $tax_class_id
	 * @return float
	 */
	public function calcTotalTaxAmount($amount, $tax_class_id) {
		$total_tax_amount = 0.0;
		if (isset($this->taxes[$tax_class_id])) {
			foreach ($this->taxes[$tax_class_id] as $tax_rate) {
				$total_tax_amount += $this->calcTaxAmount($amount, $tax_rate);			
			}					
		}
    	return $total_tax_amount;
	}
	
	/**
	 * Calculate applicable tax amount based on the amount and tax rate record provided
	 * @param float $amount
	 * @param array $tax_rate
	 * @return float
	 */
	public function calcTaxAmount($amount, $tax_rate = array() ) {
		$tax_amount = 0.0;
		if (!empty($tax_rate) && isset($tax_rate['rate'])) {
			//Validate tax class rules if condition present and see if applicable
			if ( $tax_rate['threshold_condition'] && is_numeric($tax_rate['threshold']) ) {
			    if ( !$this->_compare($amount, $tax_rate['threshold'], $tax_rate['threshold_condition']) ) {
			    	//does not match. get out
			    	return 0.0;
			    }
			}

			if ( $tax_rate['rate_prefix'] == '$'  ) {
			    //this is absolute value rate in default currency 
			    $tax_amount = $tax_rate['rate'];
			} else {
			    //This is percent based rate
			    $tax_amount = $amount * $tax_rate['rate'] / 100;
			}
		}
    	return $tax_amount;
	}

	/**
	 * Get array with applicable rates for tax class based on the provided amount
	 * Array returns Absolute and Percent rates in separate arrays
	 *
	 * @param float $amount
	 * @param $tax_class_id
	 * @return array
	 */
	public function getAplicableRates($amount, $tax_class_id) {
  		$rates = array();
		if (isset($this->taxes[$tax_class_id])) {
			foreach ($this->taxes[$tax_class_id] as $tax_rate) {
				if (!empty($tax_rate) && isset($tax_rate['rate'])) {
					if ( $tax_rate['threshold_condition'] && is_numeric($tax_rate['threshold']) ) {
						if ( !$this->_compare($amount, $tax_rate['threshold'], $tax_rate['threshold_condition']) ) {
							continue;
						}
					}
					if ( $tax_rate['rate_prefix'] == '$'  ) {
					    $rates['absolute'][] = $tax_rate['rate'];   
					} else {
					    $rates['percent'][] = $tax_rate['rate'];  
					}					
				}
			}
		}
		return $rates;
	}
		
	/**
	 * Get accumulative tax rate (deprecated)
	 * @deprecated	since 1.1.8
	 * @param int $tax_class_id
	 * @return float
	 */
	public function getRate($tax_class_id) {
		if (isset($this->taxes[$tax_class_id])) {
			$rate = 0.0;
			foreach ($this->taxes[$tax_class_id] as $tax_rate) {
				$rate += $tax_rate['rate'];
			}
			
			return $rate;
		} else {
    		return 0.0;
		}
	}

	/**
	 * @param int $tax_class_id
	 * @return array
	 */
	public function getDescription($tax_class_id) {
		return (isset($this->taxes[$tax_class_id]) ? $this->taxes[$tax_class_id] : array());
  	}

	/**
	 * @param int $tax_class_id
	 * @return bool
	 */
	public function has($tax_class_id) {
		return isset($this->taxes[$tax_class_id]);
  	}

	/**
	 * @param float $value1
	 * @param float $value2
	 * @param string $operator
	 * @return bool
	 */
	private function _compare($value1, $value2, $operator) {
        switch ($operator) {
            case 'eq':
                return ($value1 == $value2);
                break;
            case 'ne':
                return ($value1 != $value2);
                break;
            case 'le':
                return ($value1 <= $value2);
                break;
            case 'ge':
                return ($value1 >= $value2);
                break;
            case 'lt':
                return ($value1 < $value2);
                break;
            case 'gt':
                return ($value1 > $value2);
                break;
            default:
                return false;
                break;
        }
    }
}