Magento version/edition helper for determining the Magento BASE version (regardless of edition) and adds functions to check if Enterprise, Professional or Community are being run.

Version.php

<?php
/**
 * Magento version/edition helper for determining the Magento BASE version (regardless of edition) and adds functions to check if Enterprise, Professional or Community are being run.
 * Adds isMageCommunity(), isMageProfessional() and isMageEnterprise()
 *
 * @category   TBT
 * @package    TBT_Rewards
 * @author     WDCA Sweet Tooth Team <contact@sweettoothhq.com>
 */
class TBT_Rewards_Helper_Version extends Mage_Core_Helper_Abstract {

	/**
	 * True if the version of Magento currently being rune is Enterprise Edition
	 */
	public function isMageEnterprise() {
	    return Mage::getConfig ()->getModuleConfig ( 'Enterprise_Enterprise' ) && Mage::getConfig ()->getModuleConfig ( 'Enterprise_AdminGws' ) && Mage::getConfig ()->getModuleConfig ( 'Enterprise_Checkout' ) && Mage::getConfig ()->getModuleConfig ( 'Enterprise_Customer' );
	}


	/**
	 * True if the version of Magento currently being rune is Enterprise Edition
	 */
	public function isMageProfessional() {
	    return Mage::getConfig ()->getModuleConfig ( 'Enterprise_Enterprise' ) && !Mage::getConfig ()->getModuleConfig ( 'Enterprise_AdminGws' ) && !Mage::getConfig ()->getModuleConfig ( 'Enterprise_Checkout' ) && !Mage::getConfig ()->getModuleConfig ( 'Enterprise_Customer' );
	}



	/**
	 * True if the version of Magento currently being rune is Enterprise Edition
	 */
	public function isMageCommunity() {
	    return !$this->isMageEnterprise() && !$this->isMageProfessional();
	}


	/**
	 * attempt to convert an Enterprise, Professional, Community magento version number to its compatable Community version
	 * 
	 * @param string $task fix problems where direct version numbers cant be changed to a community release without knowing the intent of the task
	 */
	public function convertVersionToCommunityVersion($version, $task = null) {
		
		/* Enterprise - 
         * 1.9 | 1.8 | 1.5
         */
		if ($this->isMageEnterprise()) {
		    if (version_compare ( $version, '1.11.0', '>=' ))
		        return '1.6.0';
			if (version_compare ( $version, '1.9.1', '>=' ))
				return '1.5.0';
			if (version_compare ( $version, '1.9.0', '>=' ))
				return '1.4.2';
			if (version_compare ( $version, '1.8.0', '>=' ))
				return '1.3.1';
			return '1.3.1';
		}
		
		/* Professional - 
         * If Entprise_Enterprise module is installed but it didn't pass Enterprise_Enterprise tests
         * then the installation must be Magento Pro edition. 
         * 1.7 | 1.8
         */
		if ($this->isMageProfessional()) {
			if (version_compare ( $version, '1.8.0', '>=' ))
				return '1.4.1';
			if (version_compare ( $version, '1.7.0', '>=' ))
				return '1.3.1';
			return '1.3.1';
		}
		
		/* Community - 
         * 1.5rc2 - December 29, 2010
         * 1.4.2 - December 8, 2010
         * 1.4.1 - June 10, 2010
         * 1.3.3.0 - (April 23, 2010) *** does this release work like to 1.4.0.1?
         * 1.4.0.1 - (February 19, 2010)
         * 1.4.0.0 - (February 12, 2010)
         * 1.3.0 - March 30, 2009 
         * 1.2.1.1 - February 23, 2009 
         * 1.1 - July 24, 2008 
         * 0.6.1316 - October 18, 2007
         */
		return $version;
	}
	

	/**
	 * Returns true if the base Magento version is what has been specified
	 * @param string $version
	 * @param unknown_type $task
	 * @return boolean
	 */
	public function isBaseMageVersion($version, $task = null) {
		// convert Magento Enterprise, Professional, Community to a base version
		$mage_base_version = $this->convertVersionToCommunityVersion ( Mage::getVersion (), $task );
		
		if (version_compare ( $mage_base_version, $version, '=' )) {
			return true;
		}
		return false;
	}
}