<?php
/**
 * Magento
 *
 * 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@magentocommerce.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade Magento to newer
 * versions in the future. If you wish to customize Magento for your
 * needs please refer to http://www.magentocommerce.com for more information.
 *
 * @category    Mage
 * @package     Mage_ImportExport
 * @copyright   Copyright (c) 2012 Magento Inc. (http://www.magentocommerce.com)
 * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */

/**
 * Abstract adapter model
 *
 * @category    Mage
 * @package     Mage_ImportExport
 * @author      Magento Core Team <core@magentocommerce.com>
 */
abstract class Mage_ImportExport_Model_Export_Adapter_Abstract
{
    /**
     * Destination file path.
     *
     * @var string
     */
    protected $_destination;

    /**
     * Header columns names.
     *
     * @var array
     */
    protected $_headerCols = null;

    /**
     * Adapter object constructor.
     *
     * @param string $destination OPTIONAL Destination file path.
     * @throws Exception
     * @return void
     */
    final public function __construct($destination = null)
    {
        if (!$destination) {
            $destination = tempnam(sys_get_temp_dir(), 'importexport_');
        }
        if (!is_string($destination)) {
            Mage::throwException(Mage::helper('importexport')->__('Destination file path must be a string'));
        }
        $pathinfo = pathinfo($destination);

        if (empty($pathinfo['dirname']) || !is_writable($pathinfo['dirname'])) {
            Mage::throwException(Mage::helper('importexport')->__('Destination directory is not writable'));
        }
        if (is_file($destination) && !is_writable($destination)) {
            Mage::throwException(Mage::helper('importexport')->__('Destination file is not writable'));
        }
        $this->_destination = $destination;

        $this->_init();
    }

    /**
     * Method called as last step of object instance creation. Can be overridden in child classes.
     *
     * @return Mage_ImportExport_Model_Export_Adapter_Abstract
     */
    protected function _init()
    {
        return $this;
    }

    /**
     * Get contents of export file.
     *
     * @return string
     */
    public function getContents()
    {
        return file_get_contents($this->_destination);
    }

    /**
     * MIME-type for 'Content-Type' header.
     *
     * @return string
     */
    public function getContentType()
    {
        return 'application/octet-stream';
    }

    /**
     * Return file extension for downloading.
     *
     * @return string
     */
    public function getFileExtension()
    {
        return '';
    }

    /**
     * Set column names.
     *
     * @param array $headerCols
     * @throws Exception
     * @return Mage_ImportExport_Model_Export_Adapter_Abstract
     */
    public function setHeaderCols(array $headerCols)
    {
        if (null !== $this->_headerCols) {
            Mage::throwException(Mage::helper('importexport')->__('Header column names already set'));
        }
        if ($headerCols) {
            foreach ($headerCols as $colName) {
                $this->_headerCols[$colName] = false;
            }
            fputcsv($this->_fileHandler, array_keys($this->_headerCols), $this->_delimiter, $this->_enclosure);
        }
        return $this;
    }

    /**
     * Write row data to source file.
     *
     * @param array $rowData
     * @return Mage_ImportExport_Model_Export_Adapter_Abstract
     */
    abstract public function writeRow(array $rowData);
}