<?php
/*
* 2007-2011 PrestaShop
*
* NOTICE OF LICENSE
*
* This source file is subject to the Open Software License (OSL 3.0)
* that is bundled with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://opensource.org/licenses/osl-3.0.php
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@prestashop.com so we can send you a copy immediately.
*
* DISCLAIMER
*
* Do not edit or add to this file if you wish to upgrade PrestaShop to newer
* versions in the future. If you wish to customize PrestaShop for your
* needs please refer to http://www.prestashop.com for more information.
*
*  @author PrestaShop SA <contact@prestashop.com>
*  @copyright  2007-2011 PrestaShop SA
*  @version  Release: $Revision$
*  @license    http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
*  International Registered Trademark & Property of PrestaShop SA
*/

/**
 * @since 1.5.0
 *
 * TaxCaculator is responsible of the tax computation
 */
class TaxCalculatorCore
{
	/**
  	 * COMBINE_METHOD sum taxes
	 * eg: 100€ * (10% + 15%)
	 */
	const COMBINE_METHOD = 1;

	/**
	 * ONE_AFTER_ANOTHER_METHOD apply taxes one after another
	 * eg: (100€ * 10%) * 15%
	 */
	const ONE_AFTER_ANOTHER_METHOD = 2;

	/**
	 * @var array $taxes_rate
	 */
	public $taxes_rate;

	/**
	 * @var int $computation_method (COMBINE_METHOD | ONE_AFTER_ANOTHER_METHOD)
	 */
	public $computation_method;


	/**
	 * @param array $taxes_rate
	 * @param int $computation_method (COMBINE_METHOD | ONE_AFTER_ANOTHER_METHOD)
	 */
	public function __construct(array $taxes_rate, $computation_method = TaxCalculator::COMBINE_METHOD)
	{
		$this->taxes_rate = $taxes_rate;
		$this->computation_method = (int)$computation_method;
	}

	/**
	 * Compute and add the taxes to the specified price
	 *
	 * @param price
	 * @return price with taxes
	 */
	public function addTaxes($price)
	{
		$total_price = $price;
		if ($this->computation_method == TaxCalculator::ONE_AFTER_ANOTHER_METHOD)
		{
			foreach ($this->taxes_rate as $tax_rate)
				$total_price = $total_price * (1 + abs($tax_rate) / 100);
		}
		else
		{
			foreach ($this->taxes_rate as $tax_rate)
			{
				if ($tax_rate != 0)
					$total_price = $total_price + ($price * (abs($tax_rate) / 100));
			}
		}
		return $total_price;
	}


	/**
	 * Compute and remove the taxes to the specified price
	 *
	 * @param price
	 * @return price without taxes
	 */
	public function removeTaxes($price)
	{
		$total_price = $price;
		if ($this->computation_method == TaxCalculator::ONE_AFTER_ANOTHER_METHOD)
		{
			foreach ($this->taxes_rate as $tax_rate)
				$total_price = $total_price / (1 + abs($tax_rate) / 100);
		}
		else
		{
			$taxes_rate = 0;
			foreach ($this->taxes_rate as $tax_rate)
				$taxes_rate += abs($tax_rate);

			$total_price = $total_price / (1 + (abs($taxes_rate) / 100));
		}

		return $total_price;
	}

	/**
	 * @return total taxes rate
	 */
	public function getTaxesRate()
	{
		$taxes_rate = 0;
		if ($this->computation_method == TaxCalculator::ONE_AFTER_ANOTHER_METHOD)
		{
			$taxes_rate = 1;
			foreach ($this->taxes_rate as $rate)
				$taxes_rate *= (1 + (abs($rate) / 100));

			$taxes_rate = $taxes_rate - 1;
			$taxes_rate = $taxes_rate * 100;
		}
		else
		{
			foreach ($this->taxes_rate as $rate)
				$taxes_rate += abs($rate);
		}

		return $taxes_rate;
	}
}