<?php

class Company_Rss_Feed
{

    protected $storeViews = array();
    protected $feedPath;
    protected $mediaConfig;
    protected $manufacturers = array();

    public function __construct()
    {
        $this->feedPath = Mage::getBaseDir() . DS . 'feed';
        $this->mediaConfig = Mage::getModel('catalog/product_media_config');

        foreach (Mage::app()->getStores() as $store) {
            if ((int) $store->getIsActive() && strpos($store->getCode(), 'preview') == false) {
                array_push($this->storeViews, $store);
            }
        }

        $attribute = Mage::getSingleton('eav/config')->getAttribute('catalog_product', 'manufacturer');
        if ($attribute->usesSource()) {
            $options = $attribute->getSource()->getAllOptions(false);
            foreach ($options as $id => $option) {
                $this->manufacturers[$option['value']] = $option['label'];
            }
        }
    }

    public function generateXml()
    {
        if (is_array($this->storeViews)) {
            foreach ($this->storeViews as $storeView) {
                $path = $this->feedPath . DS . $storeView->getCode();
                $feedFile = 'products.xml';

                $io = new Varien_Io_File();
                $io->setAllowCreateFolders(true);
                $io->open(array('path' => $path));

                if ($io->fileExists($path) && ! $io->isWriteable($path)) {
                    Mage::throwException('File "%s" cannot be saved. Please, make sure the directory "%s" is writeable by web server.', $feedFile, $path);
                }

                $io->streamOpen($feedFile);
                $io->streamWrite('<?xml version="1.0" encoding="UTF-8"?>' . PHP_EOL);
                $io->streamWrite('<products>' . PHP_EOL);

                $collection = $this->__getProductCollection($storeView);
                foreach ($collection as $product) {
                    $object = new Varien_Object();
                    $object->setData(array(
                        'name' => $product->getName(),
                        'sku' => $product->getSku(),
                        'category' => $product->getCategoryName(),
                        'brand' => isset($this->manufacturers[$product->getManufacturer()]) ? $this->manufacturers[$product->getManufacturer()] : null,
                        'image' => $this->mediaConfig->getMediaUrl($product->getImage()),
                        'price' => $product->getFinalPrice(),
                        'currency' => $storeView->getCurrentCurrencyCode(),
                        'description' => $product->getDescription(),
                        'url' => $storeView->getBaseUrl(Mage_Core_Model_Store::URL_TYPE_LINK) . $product->getCategoryPath() . $product->getUrlPath()
                    ));
                    $io->streamWrite($object->toXml());
                }

                $io->streamWrite('</products>' . PHP_EOL);
                $io->streamClose();
            }
        }
    }

    private function __getProductCollection($storeView)
    {
        $collection = Mage::getResourceModel('catalog/product_collection');
        $collection
            ->addStoreFilter($storeView->getId())
            ->addAttributeToSelect(array('name', 'price', 'description', 'url_path', 'sku', 'manufacturer', 'image'))
            ->addAttributeToFilter('visibility', Mage::getSingleton('catalog/product_visibility')->getVisibleInCatalogIds())
            ->addAttributeToFilter('status', Mage::getSingleton('catalog/product_status')->getVisibleStatusIds())
            ->joinField('category_id', 'catalog/category_product', 'category_id', 'product_id=entity_id', null, 'left')
            ->joinTable('catalog_category_flat_store_' . $storeView->getId(), 'entity_id=category_id', array('category_path' => 'url_path', 'category_name' => 'name'), null, 'inner')
            ->groupByAttribute('entity_id');

        return $collection;
    }

}