Esi.php

<?php

/**
 * Nexcess.net Turpentine Extension for Magento
 * Copyright (C) 2012  Nexcess.net L.L.C.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

class Nexcessnet_Turpentine_Model_Observer_Esi extends Varien_Event_Observer {
    /**
     * Set a cookie with the customer group id when customer logs in
     *
     * Events: customer_login
     *
     * @param Varien_Object $eventObject
     * @return null
     */
    public function setCustomerGroupCookie($eventObject) {
        $customer = $eventObject->getCustomer();
        $cookie = Mage::getSingleton('core/cookie');
        if (Mage::getStoreConfig('persistent/options/enabled')) {
            $cookie->set('customer_group', $customer->getGroupId(), Mage::getStoreConfig('persistent/options/lifetime'));
        } else {
            $cookie->set('customer_group', $customer->getGroupId());
        }
    }

    /**
     * Destroy the cookie with the customer group when customer logs out
     *
     * Events: customer_logout
     *
     * @param Varien_Object $eventObject
     * @return null
     */
    public function removeCustomerGroupCookie($eventObject) {
        Mage::getSingleton('core/cookie')->delete('customer_group');
    }

    /**
     * Check the ESI flag and set the ESI header if needed
     *
     * Events: http_response_send_before
     *
     * @param  Varien_Object $eventObject
     * @return null
     */
    public function setFlagHeaders($eventObject) {
        $response = $eventObject->getResponse();
        if (Mage::helper('turpentine/esi')->shouldResponseUseEsi()) {
            $response->setHeader('X-Turpentine-Esi',
                Mage::registry('turpentine_esi_flag') ? '1' : '0');
            Mage::helper('turpentine/debug')->logDebug(
                'Set ESI flag header to: %s',
                (Mage::registry('turpentine_esi_flag') ? '1' : '0') );
        }
    }

    /**
     * Allows disabling page-caching by setting the cache flag on a controller
     *
     *   <customer_account>
     *     <turpentine_cache_flag value="0" />
     *   </customer_account>
     *
     * Events: controller_action_layout_generate_blocks_after
     *
     * @param  Varien_Object $eventObject
     * @return null
     */
    public function checkCacheFlag($eventObject) {
        if (Mage::helper('turpentine/varnish')->shouldResponseUseVarnish()) {
            $layoutXml = $eventObject->getLayout()->getUpdate()->asSimplexml();
            foreach ($layoutXml->xpath('//turpentine_cache_flag') as $node) {
                foreach ($node->attributes() as $attr => $value) {
                    if ($attr == 'value') {
                        if ( ! (string) $value) {
                            Mage::register('turpentine_nocache_flag', true, true);
                            return; //only need to set the flag once
                        }
                    }
                }
            }
        }
    }

    /**
     * On controller redirects, check the target URL and set to home page
     * if it would otherwise go to a getBlock URL
     *
     * @param  Varien_Object $eventObject
     * @return null
     */
    public function checkRedirectUrl($eventObject) {
        $esiHelper = Mage::helper('turpentine/esi');
        $url = $eventObject->getTransport()->getUrl();
        $referer = Mage::helper('core/http')->getHttpReferer();
        $dummyUrl = $esiHelper->getDummyUrl();
        $reqUenc = Mage::helper('core')->urlDecode(
            Mage::app()->getRequest()->getParam('uenc') );

        if ($this->_checkIsEsiUrl($url)) {
            if ($this->_checkIsNotEsiUrl($reqUenc) &&
                    Mage::getBaseUrl() == $url) {
                $newUrl = $this->_fixupUencUrl($reqUenc);
            } elseif ($this->_checkIsNotEsiUrl($referer)) {
                $newUrl = $referer;
            } else {
                $newUrl = $dummyUrl;
            }
            // TODO: make sure this actually looks like a URL
            $eventObject->getTransport()->setUrl($newUrl);
        }

        if ($eventObject->getTransport()->getUrl() != $url) {
            Mage::helper('turpentine/debug')->logDebug(
                'Detected redirect to ESI URL, changing: %s => %s',
                $url, $eventObject->getTransport()->getUrl() );
        }
    }

    /**
     * Load the cache clear events from stored config
     *
     * @param  Varien_Object $eventObject
     * @return null
     */
    public function loadCacheClearEvents($eventObject) {
        Varien_Profiler::start('turpentine::observer::esi::loadCacheClearEvents');
        $events = Mage::helper('turpentine/esi')->getCacheClearEvents();
        $appShim = Mage::getSingleton('turpentine/shim_mage_core_app');
        foreach ($events as $ccEvent) {
            $appShim->shim_addEventObserver('global', $ccEvent,
                'turpentine_ban_'.$ccEvent, 'singleton',
                'turpentine/observer_ban', 'banClientEsiCache');
        }
        Varien_Profiler::stop('turpentine::observer::esi::loadCacheClearEvents');
    }

    /**
     * Add the core/messages block rewrite if the flash message fix is enabled
     *
     * The core/messages block is rewritten because it doesn't use a template
     * we can replace with an ESI include tag, just dumps out a block of
     * hard-coded HTML and also frequently skips the toHtml method
     *
     * @param Varien_Object $eventObject
     * @return null
     */
    public function addMessagesBlockRewrite($eventObject) {
        if (Mage::helper('turpentine/esi')->shouldFixFlashMessages()) {
            Varien_Profiler::start('turpentine::observer::esi::addMessagesBlockRewrite');
            Mage::getSingleton('turpentine/shim_mage_core_app')
                ->shim_addClassRewrite('block', 'core', 'messages',
                    'Nexcessnet_Turpentine_Block_Core_Messages');
            Varien_Profiler::stop('turpentine::observer::esi::addMessagesBlockRewrite');
        }
    }

    /**
     * Check the magento version and runtime env and set the replace_form_key
     * flag if needed
     *
     * @param Varien_Object $eventObject
     * @return null
     */
    public function setReplaceFormKeyFlag($eventObject) {
        $esiHelper = Mage::helper('turpentine/esi');
        $varnishHelper = Mage::helper('turpentine/varnish');
        $request = Mage::app()->getRequest();
        if ($esiHelper->shouldResponseUseEsi() &&
                $varnishHelper->csrfFixupNeeded() &&
                ! $request->isPost()) {
            Mage::register('replace_form_key', true);
        }
    }

    /**
     * Replace the form key placeholder with the ESI include fragment
     *
     * @param  Varien_Object $eventObject
     * @return null
     */
    public function replaceFormKeyPlaceholder($eventObject) {
        if (Mage::registry('replace_form_key')) {
            $esiHelper = Mage::helper('turpentine/esi');
            $response = $eventObject->getResponse();
            $responseBody = $response->getBody();
            $responseBody = str_replace('{{form_key_esi_placeholder}}',
                $esiHelper->buildEsiIncludeFragment(
                    $esiHelper->getFormKeyEsiUrl() ),
                $responseBody);
            $response->setBody($responseBody);
        }
    }

    /**
     * Encode block data in URL then replace with ESI template
     *
     * @link https://github.com/nexcess/magento-turpentine/wiki/ESI_Cache_Policy
     *
     * Events: core_block_abstract_to_html_before
     *
     * @param  Varien_Object $eventObject
     * @return null
     */
    public function injectEsi($eventObject) {
        $blockObject = $eventObject->getBlock();
        $dataHelper = Mage::helper('turpentine/data');
        $esiHelper = Mage::helper('turpentine/esi');
        $debugHelper = Mage::helper('turpentine/debug');
        if ($esiHelper->getEsiBlockLogEnabled()) {
            $debugHelper->logInfo(
                'Checking ESI block candidate: %s',
                $blockObject->getNameInLayout() ? $blockObject->getNameInLayout() : $blockObject->getModuleName() );

            $debugHelper->logInfo("-- block testing: shouldResponseUseEsi = ".$esiHelper->shouldResponseUseEsi());
            $debugHelper->logInfo("-- block testing: instanceof Mage_Core_Block_Template = ".$blockObject instanceof Mage_Core_Block_Template);
            $debugHelper->logInfo("-- block testing: Esi Options = ".print_r($blockObject->getEsiOptions(), true));
        }        
        if ($esiHelper->shouldResponseUseEsi() &&
                $blockObject instanceof Mage_Core_Block_Template &&
                $esiOptions = $blockObject->getEsiOptions()) {

            if ((isset($esiOptions['disableEsiInjection'])) && ($esiOptions['disableEsiInjection'] == 1)) { 
                if ($esiHelper->getEsiBlockLogEnabled()) {
                    $debugHelper->logInfo("-- ESI Injection disabled");
                }
                return;
            }

            if (Mage::app()->getStore()->getCode() == 'admin') {
                // admin blocks are not allowed to be cached for now
                $debugHelper->logWarn(
                    'Ignoring attempt to inject adminhtml block: %s',
                    $blockObject->getNameInLayout() ? $blockObject->getNameInLayout() : $blockObject->getModuleName() );
                return;
            } elseif ($esiHelper->getEsiBlockLogEnabled()) {
                $debugHelper->logInfo('Block check passed, injecting block: %s',
                    $blockObject->getNameInLayout() ? $blockObject->getNameInLayout() : $blockObject->getModuleName());
            }
            Varien_Profiler::start('turpentine::observer::esi::injectEsi');
            $ttlParam = $esiHelper->getEsiTtlParam();
            $cacheTypeParam = $esiHelper->getEsiCacheTypeParam();
            $dataParam = $esiHelper->getEsiDataParam();
            $methodParam = $esiHelper->getEsiMethodParam();
            $hmacParam = $esiHelper->getEsiHmacParam();
            $scopeParam = $esiHelper->getEsiScopeParam();
            $referrerParam = $esiHelper->getEsiReferrerParam();

            $esiOptions = $this->_getDefaultEsiOptions($esiOptions);

            // change the block's template to the stripped down ESI template
            switch ($esiOptions[$methodParam]) {
                case 'ajax':
                    $blockObject->setTemplate('turpentine/ajax.phtml');
                    break;

                case 'esi':
                default:
                    $blockObject->setTemplate('turpentine/esi.phtml');
                    // flag request for ESI processing
                    Mage::register('turpentine_esi_flag', true, true);
            }

            // esi data is the data needed to regenerate the ESI'd block
            $esiData = $this->_getEsiData($blockObject, $esiOptions)->toArray();
            ksort($esiData);
            $frozenData = $dataHelper->freeze($esiData);
            $urlOptions = array(
                $methodParam    => $esiOptions[$methodParam],
                $cacheTypeParam => $esiOptions[$cacheTypeParam],
                $ttlParam       => $esiOptions[$ttlParam],
                $hmacParam      => $dataHelper->getHmac($frozenData),
                $dataParam      => $frozenData,
            );
            if ($esiOptions[$methodParam] == 'ajax') {
                $urlOptions['_secure'] = Mage::app()->getStore()
                    ->isCurrentlySecure();
            }
            if ($esiOptions[$scopeParam] == 'page') {
                $urlOptions[$referrerParam] = Mage::helper('core')->urlEncode(
                    Mage::getUrl('*/*/*', array('_use_rewrite' => true, '_current' => true))
                );
            }

            /**
             * Keep params from original url
             */
            $urlOptions['_query'] = Mage::app()->getRequest()->getParams();
            
            $esiUrl = Mage::getUrl('turpentine/esi/getBlock', $urlOptions);
            if ($esiOptions[$methodParam] == 'esi') {
                // setting [web/unsecure/base_url] can be https://... but ESI can never be HTTPS
                $esiUrl = preg_replace('|^https://|i', 'http:https://', $esiUrl);
            }
            $blockObject->setEsiUrl($esiUrl);
            // avoid caching the ESI template output to prevent the double-esi-
            // include/"ESI processing not enabled" bug
            foreach (array('lifetime', 'tags', 'key') as $dataKey) {
                $blockObject->unsetData('cache_'.$dataKey);
            }
            if (strlen($esiUrl) > 2047) {
                Mage::helper('turpentine/debug')->logWarn(
                    'ESI url is probably too long (%d > 2047 characters): %s',
                    strlen($esiUrl), $esiUrl );
            }
            Varien_Profiler::stop('turpentine::observer::esi::injectEsi');
        } // else handle the block like normal and cache it inline with the page
    }

    /**
     * Generate ESI data to be encoded in URL
     *
     * @param  Mage_Core_Block_Template $blockObject
     * @param  array $esiOptions
     * @return Varien_Object
     */
    protected function _getEsiData($blockObject, $esiOptions) {
        Varien_Profiler::start('turpentine::observer::esi::_getEsiData');
        $esiHelper = Mage::helper('turpentine/esi');
        $cacheTypeParam = $esiHelper->getEsiCacheTypeParam();
        $scopeParam = $esiHelper->getEsiScopeParam();
        $methodParam = $esiHelper->getEsiMethodParam();
        $esiData = new Varien_Object();
        $esiData->setStoreId(Mage::app()->getStore()->getId());
        $esiData->setDesignPackage(Mage::getDesign()->getPackageName());
        $esiData->setDesignTheme(Mage::getDesign()->getTheme('layout'));
        $esiData->setNameInLayout($blockObject->getNameInLayout());
        $esiData->setBlockType(get_class($blockObject));
        $esiData->setLayoutHandles($this->_getBlockLayoutHandles($blockObject));
        $esiData->setEsiMethod($esiOptions[$methodParam]);
        if ($esiOptions[$cacheTypeParam] == 'private' || $esiOptions[$cacheTypeParam] == 'customer_group') {
            if (is_array(@$esiOptions['flush_events'])) {
                $esiData->setFlushEvents(array_merge(
                    $esiHelper->getDefaultCacheClearEvents(),
                    array_keys($esiOptions['flush_events']) ));
            } else {
                $esiData->setFlushEvents(
                    $esiHelper->getDefaultCacheClearEvents() );
            }
        }
        if ($esiOptions[$scopeParam] == 'page') {
            $esiData->setParentUrl(Mage::app()->getRequest()->getRequestString());
        }
        if (is_array($esiOptions['dummy_blocks'])) {
            $dummyBlocks = array();
            foreach ($esiOptions['dummy_blocks'] as $key => $value) {
                $dummyBlocks[] = (empty($value) && ! is_numeric($key)) ? $key : $value;
            }
            $esiData->setDummyBlocks($dummyBlocks);
        } else {
            Mage::helper('turpentine/debug')->logWarn(
                'Invalid dummy_blocks for block: %s',
                $blockObject->getNameInLayout() );
        }
        $simpleRegistry = array();
        $complexRegistry = array();
        if (is_array($esiOptions['registry_keys'])) {
            foreach ($esiOptions['registry_keys'] as $key => $options) {
                $value = Mage::registry($key);
                if ($value) {
                    if (is_object($value) &&
                            $value instanceof Mage_Core_Model_Abstract) {
                        $complexRegistry[$key] =
                            $this->_getComplexRegistryData($options, $value);
                    } else {
                        $simpleRegistry[$key] = $value;
                    }
                }
            }
        } else {
            Mage::helper('turpentine/debug')->logWarn(
                'Invalid registry_keys for block: %s',
                $blockObject->getNameInLayout() );
        }
        $esiData->setSimpleRegistry($simpleRegistry);
        $esiData->setComplexRegistry($complexRegistry);
        Varien_Profiler::stop('turpentine::observer::esi::_getEsiData');
        return $esiData;
    }

    /**
     * Get the active layout handles for this block and any child blocks
     *
     * This is probably kind of slow since it uses a bunch of xpath searches
     * but this was the easiest way to get the info needed. Should be a target
     * for future optimization
     *
     * There is an issue with encoding the used handles in the URL, if the used
     * handles change (ex customer logs in), the cached version of the page will
     * still have the old handles encoded in it's ESI url. This can lead to
     * weirdness like the "Log in" link displaying for already logged in
     * visitors on pages that were initially visited by not-logged-in visitors.
     * Not sure of a solution for this yet.
     *
     * Above problem is currently solved by EsiController::_swapCustomerHandles()
     * but it would be best to find a more general solution to this.
     *
     * @param  Mage_Core_Block_Template $block
     * @return array
     */
    protected function _getBlockLayoutHandles($block) {
        Varien_Profiler::start('turpentine::observer::esi::_getBlockLayoutHandles');
        $layout = $block->getLayout();
        $layoutXml = Mage::helper('turpentine/esi')->getLayoutXml();
        $activeHandles = array();
        // get the xml node representing the block we're working on (from the
        // default handle probably)
        $blockNode = Mage::helper('turpentine/esi')->getEsiLayoutBlockNode(
            $layout, $block->getNameInLayout());
        $childBlocks = Mage::helper('turpentine/data')
            ->getChildBlockNames($blockNode);
        foreach ($childBlocks as $blockName) {
            foreach ($layout->getUpdate()->getHandles() as $handle) {
                // check if this handle has any block or reference tags that
                // refer to this block or a child block, unless the handle name
                // is blank
                if ($handle !== '' && (strpos($handle, 'THEME') === 0 ||
                    $layoutXml->xpath(sprintf(
                        '//%s//*[@name=\'%s\']', $handle, $blockName )))) {
                    $activeHandles[] = $handle;
                }
            }
        }
        if ( ! $activeHandles) {
            $activeHandles[] = 'default';
        }
        Varien_Profiler::stop('turpentine::observer::esi::_getBlockLayoutHandles');
        return array_unique($activeHandles);
    }

    /**
     * Get the default ESI options
     *
     * @return array
     */
    protected function _getDefaultEsiOptions($options) {
        $esiHelper = Mage::helper('turpentine/esi');
        $ttlParam = $esiHelper->getEsiTtlParam();
        $methodParam = $esiHelper->getEsiMethodParam();
        $cacheTypeParam = $esiHelper->getEsiCacheTypeParam();
        $defaults = array(
            $esiHelper->getEsiMethodParam()         => 'esi',
            $esiHelper->getEsiScopeParam()          => 'global',
            $esiHelper->getEsiCacheTypeParam()      => 'public',
            'dummy_blocks'      => array(),
            'registry_keys'     => array(),
        );
        $options = array_merge($defaults, $options);

        // set the default TTL
        if ( ! isset($options[$ttlParam])) {
            if ($options[$cacheTypeParam] == 'private' || $options[$cacheTypeParam] == 'customer_group') {
                switch ($options[$methodParam]) {
                    case 'ajax':
                        $options[$ttlParam] = '0';
                        break;

                    case 'esi':
                    default:
                        $options[$ttlParam] = $esiHelper->getDefaultEsiTtl();
                        break;
                }
            } else {
                $options[$ttlParam] = Mage::helper('turpentine/varnish')
                    ->getDefaultTtl();
            }
        }

        return $options;
    }

    /**
     * Get the complex registry entry data
     *
     * @param  array $valueOptions
     * @param  mixed $value
     * @return array
     */
    protected function _getComplexRegistryData($valueOptions, $value) {
        $idMethod = @$valueOptions['id_method'] ?
            $valueOptions['id_method'] : 'getId';
        $model = @$valueOptions['model'] ?
            $valueOptions['model'] : Mage::helper('turpentine/data')
                ->getModelName($value);
        $data = array(
            'model'         => $model,
            'id'            => $value->{$idMethod}(),
        );
        return $data;
    }

    /**
     * Fix a URL to ensure it uses Magento's base URL instead of the backend
     * URL
     *
     * @param  string $uencUrl
     * @return string
     */
    protected function _fixupUencUrl($uencUrl) {
        $esiHelper = Mage::helper('turpentine/esi');
        $corsOrigin = $esiHelper->getCorsOrigin();
        if ($corsOrigin != $esiHelper->getCorsOrigin($uencUrl)) {
            return $corsOrigin.parse_url($uencUrl, PHP_URL_PATH);
        } else {
            return $uencUrl;
        }
    }

    /**
     * Check if a URL *is not* for the /turpentine/esi/getBlock/ action
     *
     * @param  string $url
     * @return bool
     */
    protected function _checkIsNotEsiUrl($url) {
        return $url && ! preg_match('~/turpentine/esi/getBlock/~', $url);
    }

    /**
     * Check if a URL *is* for the /turpentine/esi/getBlock/ action
     *
     * @param  string $url
     * @return bool
     */
    protected function _checkIsEsiUrl($url) {
        return ! $this->_checkIsNotEsiUrl($url);
    }

    public function hookToControllerActionPreDispatch($observer) {
        if (Mage::helper('turpentine/data')->getVclFix() == 0 && $observer->getEvent()->getControllerAction()->getFullActionName() == 'checkout_cart_add') {
            Mage::dispatchEvent("add_to_cart_before", array('request' => $observer->getControllerAction()->getRequest()));
        }
        if ($observer->getEvent()->getControllerAction()->getFullActionName() == 'wishlist_index_index') {
            Mage::dispatchEvent('wishlist_index_index_before', array('request' => $observer->getControllerAction()->getRequest()));
        }
    }

    public function hookToControllerActionPostDispatch($observer) {
        if ($observer->getEvent()->getControllerAction()->getFullActionName() == 'checkout_cart_add') {
            Mage::dispatchEvent("add_to_cart_after", array('request' => $observer->getControllerAction()->getRequest()));
        }
    }
    
    public function hookToAddToCartBefore($observer) {
        //Mage::log("hookToAddToCartBefore-antes ".print_r($observer->getEvent()->getRequest()->getParams(),true)." will be added to cart.", null, 'carrinho.log', true);
        $key = Mage::getSingleton('core/session')->getFormKey();
        $observer->getEvent()->getRequest()->setParam('form_key', $key);
        $request = $observer->getEvent()->getRequest()->getParams();
        //Mage::log("hookToAddToCartBefore ".print_r($request,true)." will be added to cart.", null, 'carrinho.log', true);
    }

    public function hookToAddToCartAfter($observer) {
        $request = $observer->getEvent()->getRequest()->getParams();
        //Mage::log("hookToAddToCartAfter ".print_r($request,true)." is added to cart.", null, 'carrinho.log', true);
    }

    /**
     * Set the form key on the add to wishlist request
     *
     * @param $observer
     *
     * @return Nexcessnet_Turpentine_Model_Observer_Esi
     */
    public function hookToAddToWishlistBefore($observer)
    {
        $key = Mage::getSingleton('core/session')->getFormKey();
        $observer->getEvent()->getRequest()->setParam('form_key', $key);
        return $this;
    }
}