woocommerce/classes/class-woocommerce-tax.php

<?php
/**
 * Performs tax calculations and loads tax rates.
 *
 * @class 		Woocommerce_Tax
 * @package		WooCommerce
 * @category	Class
 * @author		WooThemes
 */
class Woocommerce_Tax {
	
	var $rates;	// Simple array of rates
	var $parsed_rates;	// Parsed into array with counties/states as keys
	
	/**
	 * Get the tax rates as an array
	 */
	function get_tax_rates() {
		if (!is_array($this->parsed_rates)) :
			global $woocommerce;
			
			$tax_rates 			= (array) get_option('woocommerce_tax_rates');
			$local_tax_rates 	= (array) get_option('woocommerce_local_tax_rates');
			
			$parsed_rates 		= array();
			$flat_rates			= array();
			$index 				= 0;
			
			foreach( $tax_rates as $rate ) :
			
				// Standard Rate?
				if (!$rate['class']) $rate['class'] = '*';
				
				// Add entry for each country/state - each will hold all matching rates
				if ($rate['countries']) foreach ($rate['countries'] as $country => $states) :
					
					if ($states) :
						
						foreach ($states as $state) :
							
							if (!$rate['label']) :
								$rate['label'] = $woocommerce->countries->tax_or_vat();
								
								// Add % to label
								if ( $rate['rate'] > 0 || $rate['rate'] === 0 ) :
									$rate['label'] .= ' ('. rtrim(rtrim($rate['rate'], '0'), '.') . '%)';
								endif;
							endif;
							
							$flat_rates[$index] = $rate;
							
							$parsed_rates[$country][$state][$rate['class']][$index] = array( 
								'label' => $rate['label'], 
								'rate' => $rate['rate'], 
								'shipping' => $rate['shipping'],
								'compound' => $rate['compound'] 
								);
							
							$index++;
							
						endforeach;
						
					endif;
				
				endforeach;
				
			endforeach;
			
			foreach( $local_tax_rates as $rate ) :
			
				// Standard Rate?
				if (!$rate['class']) $rate['class'] = '*';
				
				if (!$rate['label']) :
					$rate['label'] = $woocommerce->countries->tax_or_vat();
					
					// Add % to label
					if ( $rate['rate'] > 0 || $rate['rate'] === 0 ) :
						$rate['label'] .= ' ('. rtrim(rtrim($rate['rate'], '0'), '.') . '%)';
					endif;
				endif;
				
				$flat_rates[$index] = $rate;
				
				$parsed_rates[$rate['country']][$rate['state']][$rate['class']][$index] = array( 
					'label' => $rate['label'], 
					'rate' => $rate['rate'], 
					'postcode' => array_map('strtoupper', (array) $rate['postcode']),
					'shipping' => $rate['shipping'],
					'compound' => $rate['compound'] 
					);
				
				$index++;
				
			endforeach;			
			
			$this->rates = $flat_rates;
			$this->parsed_rates = $parsed_rates;
		endif;
	}
	
	/**
	 * Searches for all matching country/state/postcode tax rates
	 *
	 * @since 	1.4
	 * @param   string	country
	 * @param	string	state
	 * @param   string	postcode
	 * @param	string	Tax Class
	 * @return  array
	 */
	function find_rates( $country = '', $state = '', $postcode = '', $tax_class = '' ) {
		$this->get_tax_rates();
		
		if (!$country) return array();
		
		if (!$state) $state = '*';
		
		$tax_class = sanitize_title($tax_class);
		if (!$tax_class) $tax_class = '*';

		$found_rates = array();

		// Look for a state specific rule
		if (isset($this->parsed_rates[ $country ][ $state ])) :
			
			// Look for tax class specific rule
			if (isset($this->parsed_rates[ $country ][ $state ][ $tax_class ])) :
				$found_rates = $this->parsed_rates[ $country ][ $state ][ $tax_class ];
			else :
				$found_rates = $this->parsed_rates[ $country ][ $state ][ '*' ];
			endif;
		
		// Default to * if not state specific rules are found
		elseif (isset($this->parsed_rates[ $country ][ '*' ])) :
		
			// Look for tax class specific rule
			if (isset($this->parsed_rates[ $country ][ '*' ][ $tax_class ])) :
				$found_rates = $this->parsed_rates[ $country ][ '*' ][ $tax_class ];
			else :
				$found_rates = $this->parsed_rates[ $country ][ '*' ][ '*' ];
			endif;
			
		endif;
		
		// Now we have an array of matching rates, lets filter this based on postcode
		$matched_tax_rates = array();
		
		foreach ($found_rates as $key => $rate) :
			
			if (isset($rate['postcode'])) :
				
				// Local rate
				if ($postcode) :
				
					// Check if postcode matches up
					if (in_array($postcode, $rate['postcode']) || sizeof($rate['postcode'])==0) $matched_tax_rates[$key] = $rate;
					
					// Check postcode ranges
					if (is_numeric($postcode)) :
						foreach ($rate['postcode'] as $rate_postcode) :
							if (strstr($rate_postcode, '-')) :
								$parts = array_map('trim', explode('-', $rate_postcode));
								if (sizeof($parts)==2 && is_numeric($parts[0]) && is_numeric($parts[1])) :
									if ($postcode>=$parts[0] && $postcode<=$parts[1]) $matched_tax_rates[$key] = $rate;
								endif;
							endif;
						endforeach;
					endif;
					
				endif;
				
			else :
				
				// Standard rate
				$matched_tax_rates[$key] = $rate;
				
			endif;
			
		endforeach;

		$matched_tax_rates = apply_filters('woocommerce_matched_tax_rates', $matched_tax_rates, $this->parsed_rates, $country, $state, $postcode, $tax_class );
		
		return $matched_tax_rates;
	}
	
	/**
	 * Get's an array of matching rates for a tax class
	 *
	 * @param   object	Tax Class
	 * @return  array
	 */
	function get_rates( $tax_class = '' ) {
		global $woocommerce;
		
		$this->get_tax_rates();
		
		$tax_class = sanitize_title($tax_class);
		
		/* Checkout uses customer location, otherwise use store base rate */
		if ( defined('WOOCOMMERCE_CHECKOUT') && WOOCOMMERCE_CHECKOUT ) :
			
			$country 	= $woocommerce->customer->get_shipping_country();
			$state 		= $woocommerce->customer->get_shipping_state();
			$postcode   = $woocommerce->customer->get_shipping_postcode();
			
			$matched_tax_rates = $this->find_rates( $country, $state, $postcode, $tax_class );
			
			return $matched_tax_rates;
		
		else :
			
			return $this->get_shop_base_rate( $tax_class );
			
		endif;

	}
	
	/**
	 * Get's an array of matching rates for the shop's base country
	 *
	 * @param   string	Tax Class
	 * @return  array
	 */
	function get_shop_base_rate( $tax_class = '' ) {
		global $woocommerce;
		
		$this->get_tax_rates();
		
		$country 	= $woocommerce->countries->get_base_country();
		$state 		= $woocommerce->countries->get_base_state();
		
		return $this->find_rates( $country, $state, '', $tax_class );
	}

	
	/**
	 * Gets an array of matching shipping tax rates for a given class
	 *
	 * @param   string	Tax Class
	 * @return  mixed		
	 */
	function get_shipping_tax_rates( $tax_class = null ) {
		global $woocommerce;
		
		$this->get_tax_rates();
		
		if (defined('WOOCOMMERCE_CHECKOUT') && WOOCOMMERCE_CHECKOUT) :
			$country 	= $woocommerce->customer->get_shipping_country();
			$state 		= $woocommerce->customer->get_shipping_state();
			$postcode   = $woocommerce->customer->get_shipping_postcode();
		else :
			$country 	= $woocommerce->countries->get_base_country();
			$state 		= $woocommerce->countries->get_base_state();
			$postcode   = '';
		endif;
		
		// If we are here then shipping is taxable - work it out
		if ( !is_null($tax_class) ) :
			
			$matched_tax_rates = array();
			
			// This will be per item shipping
			$rates = $this->find_rates( $country, $state, $postcode, $tax_class );
			
			if ($rates) foreach ($rates as $key => $rate) :
				if (isset($rate['shipping']) && $rate['shipping']=='yes') :
					$matched_tax_rates[$key] = $rate;
				endif;
			endforeach;
			
			if (sizeof($matched_tax_rates)==0) :
				// Get standard rate
				$rates = $this->find_rates( $country, $state, $postcode );
				
				if ($rates) foreach ($rates as $key => $rate) :
					if (isset($rate['shipping']) && $rate['shipping']=='yes') :
						$matched_tax_rates[$key] = $rate;
					endif;
				endforeach;
			endif;
			
			return $matched_tax_rates;
			
		else :
			
			// This will be per order shipping - loop through the order and find the highest tax class rate
			$found_tax_classes = array();
			$matched_tax_rates = array();
			$rates = false;
			
			// Loop cart and find the highest tax band
			if (sizeof($woocommerce->cart->get_cart())>0) : foreach ($woocommerce->cart->get_cart() as $item) :
				
				$found_tax_classes[] = $item['data']->get_tax_class();
				
			endforeach; endif;
			
			$found_tax_classes = array_unique( $found_tax_classes );
			
			// If multiple classes are found, use highest
			if (sizeof($found_tax_classes)>1) :
				
				if (in_array('', $found_tax_classes)) :
					$rates = $this->find_rates( $country, $state, $postcode );
				else :
					$tax_classes = array_filter(array_map('trim', explode("\n", get_option('woocommerce_tax_classes'))));
					
					foreach ($tax_classes as $tax_class) :
						if (in_array( $tax_class, $found_tax_classes )) :
							$rates = $this->find_rates( $country, $state, $postcode, $tax_class );
							break;
						endif;
					endforeach;
				endif;

			// If a single tax class is found, use it
			elseif (sizeof($found_tax_classes)==1) :
			
				$rates = $this->find_rates( $country, $state, $postcode, $found_tax_classes[0] );
			
			endif;
			
			// If no classes are found, use standard rates
			if (!$rates) :
				$rates = $this->find_rates( $country, $state, $postcode );	
			endif;
			
			if ($rates) foreach ($rates as $key => $rate) :
				if (isset($rate['shipping']) && $rate['shipping']=='yes') :
					$matched_tax_rates[$key] = $rate;
				endif;
			endforeach;
			
			return $matched_tax_rates;
			
		endif;

		return array(); // return false
	}
	
	/**
	 * Calculate the tax using a passed array of rates
	 *
	 * @param   float	price
	 * @param   array	rates
	 * @param	bool	passed price includes tax
	 * @return  array	array of rates/amounts
	 */
	function calc_tax( $price, $rates, $price_includes_tax = true ) {
		
		$price = $price * 100;	// To avoid float rounding errors, work with integers (pence)
		
		// Taxes array
		$taxes = array();
		
		// Price inc tax
		if ($price_includes_tax) :
			
			$regular_tax_rates = 0;
			$compound_tax_rates = 0;
			
			foreach ($rates as $key => $rate) :
				if ($rate['compound']=='yes')
					$compound_tax_rates = $compound_tax_rates + $rate['rate'];
				else
					$regular_tax_rates = $regular_tax_rates + $rate['rate'];
			endforeach;
			
			$regular_tax_rate = 1 + ($regular_tax_rates / 100);
			$compound_tax_rate = 1 + ($compound_tax_rates / 100);
			$tax_rate = $regular_tax_rate * $compound_tax_rate;
			
			$non_compound_price = ($price/$compound_tax_rate);
			// $price = ($x * $regular_tax_rate) * $compound_tax_rate;
			
			foreach ($rates as $key => $rate) :
				
				$the_rate = $rate['rate'] / 100;
				
				if ($rate['compound']=='yes')
					$tax_amount = ( $the_rate / $compound_tax_rate ) * $price;
				else
					$tax_amount = ( $the_rate / $regular_tax_rate ) * $non_compound_price;
				
				// Back to pounds
				$tax_amount = ($tax_amount / 100);
				
				// Rounding
				if ( get_option( 'woocommerce_tax_round_at_subtotal' ) == 'no' ) :
					$tax_amount = round( $tax_amount, 2 );
				endif;
				
				// Add rate
				if (!isset($taxes[$key])) $taxes[$key] = $tax_amount; else $taxes[$key] += $tax_amount;

			endforeach;
		
		// Prices ex tax
		else :

			// Multiple taxes
			foreach ($rates as $key => $rate) :
				if ($rate['compound']=='yes') continue;
				
				$tax_amount = $price * ($rate['rate']/100);
				
				// Back to pounds
				$tax_amount = ($tax_amount / 100);
				
				// Rounding
				if ( get_option( 'woocommerce_tax_round_at_subtotal' ) == 'no' ) :
					$tax_amount = round( $tax_amount, 2 );
				endif;
				
				// Add rate
				if (!isset($taxes[$key])) $taxes[$key] = $tax_amount; else $taxes[$key] += $tax_amount;
	
			endforeach;
			
			$pre_compound_total = array_sum($taxes);
			
			// Compound taxes
			foreach ($rates as $key => $rate) :
				if ($rate['compound']=='no') continue;
				
				$the_price_inc_tax = $price + ($pre_compound_total * 100);
				
				$tax_amount = $the_price_inc_tax * ($rate['rate']/100);
	
				// Back to pounds
				$tax_amount = ($tax_amount / 100);
				
				// Rounding
				if ( get_option( 'woocommerce_tax_round_at_subtotal' ) == 'no' ) :
					$tax_amount = round( $tax_amount, 2 );
				endif;
				
				// Add rate
				if (!isset($taxes[$key])) $taxes[$key] = $tax_amount; else $taxes[$key] += $tax_amount;
	
			endforeach;

		endif;

		return $taxes;
	}
	
	/**
	 * Calculate the shipping tax using a passed array of rates
	 *
	 * @param   int		Price
	 * @param	int		Taxation Rate
	 * @return  int		
	 */
	function calc_shipping_tax( $price, $rates ) {

		// Taxes array
		$taxes = array();
		
		// Multiple taxes
		foreach ($rates as $key => $rate) :
			if ($rate['compound']=='yes') continue;
			
			$tax_amount = $price * ($rate['rate']/100);
			
			// Add rate
			if (!isset($taxes[$key])) $taxes[$key] = $tax_amount; else $taxes[$key] += $tax_amount;

		endforeach;

		$pre_compound_total = array_sum($taxes);
		
		// Compound taxes
		foreach ($rates as $key => $rate) :
			if ($rate['compound']=='no') continue;
			
			$the_price_inc_tax = $price + $pre_compound_total;
			
			$tax_amount = $the_price_inc_tax * ($rate['rate']/100);
			
			// Add rate
			if (!isset($taxes[$key])) $taxes[$key] = $tax_amount; else $taxes[$key] += $tax_amount;

		endforeach;

		return $taxes;
	}
	
	/**
	 * Return true/false depending on if a rate is a compound rate
	 *
	 * @param   int		key
	 * @return  bool		
	 */
	function is_compound( $key ) {
		if (isset($this->rates[$key]) && $this->rates[$key]['compound']=='yes') return true;
		return false;
	}

	/**
	 * Return a given rates label
	 *
	 * @param   int		key
	 * @return  string		
	 */
	function get_rate_label( $key ) {
		if (isset($this->rates[$key]) && $this->rates[$key]['label']) return $this->rates[$key]['label'];
		return '';
	}
	
	/**
	 * Round tax lines and return the sum
	 *
	 * @param   array
	 * @return  float		
	 */
	function get_tax_total( $taxes ) {
		return array_sum(array_map(array(&$this, 'round'), $taxes));
	}
	
	/**
	 * Round tax lines
	 *
	 * @param   array
	 * @return  float		
	 */
	function get_taxes_rounded( $taxes ) {
		return array_map(array(&$this, 'round'), $taxes);
	}
	
	/** 
	 * Round to 2 DP
	 */
	function round( $in ) {
		return round($in, 2);
	}
	
}