Zeile 247 - 271 muss noch optimiert werden, aber die Logik erschließt sich mir noch nicht ;-)

ProductPriceFinder.php

<?php if (!defined('TL_ROOT')) die('You can not access this file directly!');

/**
 * Contao Open Source CMS
 * Copyright (C) 2005-2010 Leo Feyer
 *
 * Formerly known as TYPOlight Open Source CMS.
 *
 * This program is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation, either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program. If not, please visit the Free
 * Software Foundation website at <http://www.gnu.org/licenses/>.
 *
 * PHP version 5
 * @copyright  Isotope eCommerce Workgroup 2009-2012
 * @author     Andreas Schempp <andreas@schempp.ch>
 * @license    http://opensource.org/licenses/lgpl-3.0.html
 */


class ProductPriceFinder extends System
{

	/**
	 * Generate price data for a given product
	 * @param IsotopeProduct
	 * @return array
	 */
	public static function findPrice(IsotopeProduct $objProduct)
	{
		$blnAdvancedPrices = $objProduct->hasAdvancedPrices();
		$blnVariantPrices = $objProduct->hasVariantPrices();

		if ($blnAdvancedPrices && $blnVariantPrices)
		{
			$arrData = self::findAdvancedVariantPrice($objProduct);
		}
		elseif ($blnAdvancedPrices)
		{
			$arrData = self::findAdvancedProductPrice($objProduct);
		}
		elseif ($blnVariantPrices)
		{
			$arrData = self::findVariantPrice($objProduct);
		}
		else
		{
			$arrData = self::findProductPrice($objProduct);
		}

		return array_merge(array
		(
		    'min'               => 1,
			'price'				=> null,
			'tax_class'			=> null,
			'from_price'		=> null,
			'high_price'		=> null,
			'price_tiers'		=> null,
		), $arrData);
	}


	/**
	 * Find price data for product without variant and without advanced prices
	 * @param IsotopeProduct
	 * @return array
	 */
	protected static function findProductPrice(IsotopeProduct $objProduct)
	{
		$arrData = $objProduct->getData();

		return array
		(
			'price'		=> $arrData['price'],
			'tax_class'	=> $arrData['tax_class'],
		);
	}


	/**
	 * Find price data for a variant product without advanced prices
	 * @param IsotopeProduct
	 * @return array
	 */
	protected static function findVariantPrice(IsotopeProduct $objProduct)
	{
		$time = time();
		$arrProduct = $objProduct->getData();

		$arrData['price'] = $arrProduct['price'];
		$arrData['tax_class'] = $arrProduct['tax_class'];

		// Only look for low price if no variant is selected
		if ($objProduct->pid == 0)
		{
			$objResult = Database::getInstance()->execute("SELECT MIN(price) AS low_price, MAX(price) AS high_price FROM tl_iso_products
															WHERE pid=" . ($objProduct->pid ? $objProduct->pid : $objProduct->id) . " AND language=''"
															. (BE_USER_LOGGED_IN === true ? '' : " AND published='1' AND (start='' OR start<$time) AND (stop='' OR stop>$time)")
															. " GROUP BY pid");

			// Must inherit price from any variant found
            $arrData['price'] = $objResult->low_price;

			if ($objResult->low_price > 0 && $objResult->low_price < $objResult->high_price)
			{
				$arrData['from_price'] = $objResult->low_price;
			}
		}

		return $arrData;
	}


	/**
	 * Find price data for a product without variant prices but with advanced prices
	 * @param IsotopeProduct
	 * @return array
	 */
	protected static function findAdvancedProductPrice(IsotopeProduct $objProduct)
	{
		return self::getAdvancedPrices(array($objProduct->id), $objProduct->quantity_requested, $objProduct->show_price_tiers);
	}


	/**
	 * Find price data for a variant product with advanced prices and with variant prices
	 * @param IsotopeProduct
	 * @return array
	 */
	protected static function findAdvancedVariantPrice(IsotopeProduct $objProduct)
	{
		$arrIds = $objProduct->pid == 0 ? $objProduct->getVariantIds() : array($objProduct->id);

		if (empty($arrIds)) {
    		return array();
		}

		$arrData = self::getAdvancedPrices($arrIds, $objProduct->quantity_requested, $objProduct->show_price_tiers);

		if ($objProduct->pid == 0)
		{
			$arrData['from_price'] = self::findLowestAdvancedPriceOfVariants($arrIds, $objProduct->show_price_tiers);
		}

		return $arrData;
	}


	/**
	 * Get advanced prices for a list of products (usially one product ID in an array, or an array of variant IDs)
	 * @param array
	 * @param int
	 * @return array
	 */
	protected static function getAdvancedPrices(array $arrIds, $intQuantity=1, $blnShowPriceTiers=false)
	{
		$time = time();
		$arrData = array();
		$blnPriceFound = false;
		$arrGroups = self::getMemberGroups();

		$objPrices = Database::getInstance()->execute("SELECT min, price, tax_class
														FROM tl_iso_price_tiers t
														LEFT JOIN tl_iso_prices p ON t.pid=p.id
														WHERE
															t.pid=
															(
																SELECT id
																FROM tl_iso_prices
																WHERE
																	config_id IN (". (int) Isotope::getInstance()->Config->id . ",0)
																	AND member_group IN(" . implode(',', $arrGroups) . ")
																	AND (start='' OR start<$time)
																	AND (stop='' OR stop>$time)
																	AND pid IN (" . implode(',', $arrIds) . ")
																ORDER BY config_id DESC, member_group=" . implode(' DESC, member_group=', $arrGroups) . " DESC, start DESC, stop DESC
																LIMIT 1
															)
														ORDER BY min DESC");

		$arrPrices = $objPrices->fetchAllAssoc();
		$blnShowPriceTiers = $objPrices->numRows > 1 ? $blnShowPriceTiers : false;

		foreach ($arrPrices as $arrPrice)
		{
			if (!$blnPriceFound && $arrPrice['min'] <= $intQuantity)
			{
				$arrData['price'] = $arrPrice['price'];
				$arrData['tax_class'] = $arrPrice['tax_class'];
				$blnPriceFound = true;
			}

            if ($blnShowPriceTiers && $arrData['from_price'] == null || $arrPrice['price'] < $arrData['from_price'])
			{
				$arrData['from_price'] = $arrPrice['price'];
			}
		}

		$arrData['price_tiers'] = array_reverse($arrPrices);

		if (!$blnPriceFound && !empty($arrPrices))
		{
    		$arrData['min'] = (int) $arrData['price_tiers'][0]['min'];
    		$arrData['price'] = $arrData['price_tiers'][0]['price'];
    		$arrData['tax_class'] = $arrData['price_tiers'][0]['tax_class'];
		}

		return $arrData;
	}


	/**
	 * Find lowest price of all variants when using advanced prices
	 * @param array
	 * @return decimal|null
	 */
	protected static function findLowestAdvancedPriceOfVariants($arrVariantIds, $blnShowPriceTiers=false)
	{
		$time = time();
		$arrGroups = self::getMemberGroups();

		if ($blnShowPriceTiers)
		{
			$objResult = Database::getInstance()->execute("SELECT MIN(price) AS low_price, MAX(price) AS high_price
                            FROM tl_iso_price_tiers
                            WHERE pid IN
                            (
                             SELECT p1.id FROM tl_iso_prices p1 LEFT JOIN tl_iso_products p2 ON p1.pid=p2.id
                             WHERE p1.pid IN (" . implode(',', $arrVariantIds) . ")
                              AND p1.config_id IN (" . (int) Isotope::getInstance()->Config->id . ",0)
                              AND p1.member_group IN(" . implode(',', $arrGroups) . ")
                              AND (p1.start='' OR p1.start<$time)
                              AND (p1.stop='' OR p1.stop>$time)
                            )");
		}
		else
		{
			$objResult = Database::getInstance()->execute("SELECT MIN(price) AS low_price, MAX(price) AS high_price 
                              FROM tl_iso_price_tiers 
                              WHERE id IN (
																SELECT id FROM (
																	SELECT *
																	FROM tl_iso_price_tiers
																	WHERE pid IN
																	(
																		SELECT id
																		FROM
																		(
																			SELECT id, pid FROM tl_iso_prices
																			WHERE
																				pid IN (" . implode(',', $arrVariantIds) . ")
																				AND config_id IN (" . (int) Isotope::getInstance()->Config->id . ",0)
																				AND member_group IN(" . implode(',', $arrGroups) . ")
																				AND (start='' OR start<$time)
																				AND (stop='' OR stop>$time)
																			ORDER BY config_id DESC, member_group=" . implode(" DESC, member_group=", $arrGroups) . " DESC, start DESC, stop DESC
																		) AS p
																		GROUP BY pid
																	)
																	ORDER BY min) price_tiers
																GROUP BY pid
															)");
		}

		return ($objResult->low_price > 0 && $objResult->low_price < $objResult->high_price) ? $objResult->low_price : null;
	}


	/**
	 * Compile a list of member groups suitable for retrieving prices. This includes a 0 at the last position in array
	 * @return array
	 */
	protected static function getMemberGroups()
	{
		if (FE_USER_LOGGED_IN === true)
		{
			$arrGroups = FrontendUser::getInstance()->groups;
		}

		if (!is_array($arrGroups))
		{
			$arrGroups = array();
		}

		$arrGroups[] = 0;

		return $arrGroups;
	}
}