<?php

namespace dokuwiki\Action;

use dokuwiki\Action\Exception\FatalException;
use dokuwiki\Sitemap\Mapper;
use dokuwiki\Utf8\PhpString;

/**
 * Class Sitemap
 *
 * Generate an XML sitemap for search engines. Do not confuse with Index
 *
 * @package dokuwiki\Action
 */
class Sitemap extends AbstractAction
{
    /** @inheritdoc */
    public function minimumPermission()
    {
        return AUTH_NONE;
    }

    /**
     * Handle sitemap delivery
     *
     * @author Michael Hamann <michael@content-space.de>
     * @throws FatalException
     * @inheritdoc
     */
    public function preProcess()
    {
        global $conf;

        if ($conf['sitemap'] < 1 || !is_numeric($conf['sitemap'])) {
            throw new FatalException('Sitemap generation is disabled', 404);
        }

        $sitemap = Mapper::getFilePath();
        if (Mapper::sitemapIsCompressed()) {
            $mime = 'application/x-gzip';
        } else {
            $mime = 'application/xml; charset=utf-8';
        }

        // Check if sitemap file exists, otherwise create it
        if (!is_readable($sitemap)) {
            Mapper::generate();
        }

        if (is_readable($sitemap)) {
            // Send headers
            header('Content-Type: ' . $mime);
            header('Content-Disposition: attachment; filename=' . PhpString::basename($sitemap));

            http_conditionalRequest(filemtime($sitemap));

            // Send file
            //use x-sendfile header to pass the delivery to compatible webservers
            http_sendfile($sitemap);

            readfile($sitemap);
            exit;
        }

        throw new FatalException('Could not read the sitemap file - bad permissions?');
    }
}
