<?php


namespace App\Http\Controllers;


use App\Models\Table;
use App\Models\User;
use XMLWriter;

class SitemapController extends Controller
{
    public function sitemap()
    {
        ob_end_clean();

        // Redirect output to a client’s web browser
        header("Content-Type: text/xml; charset=utf-8");
        // Cache headers
        header('Cache-Control: max-age=0');
        // IE9
        header('Cache-Control: max-age=1');
        // Other IE headers
        header('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); // Date in the past
        header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT'); // always modified
        header('Cache-Control: cache, must-revalidate'); // HTTP/1.1
        header('Pragma: no-cache'); // HTTP/1.0

        $xmlWriter = new XMLWriter();
        $xmlWriter->openURI('php://output');
        $xmlWriter->startDocument('1.0', 'UTF-8');
        $xmlWriter->setIndent(true);
        {
            $xmlWriter->startElement('urlset');
            {
                $xmlWriter->writeAttribute('xmlns', 'http://www.sitemaps.org/schemas/sitemap/0.9');
                foreach ($this->iterateTables() as $entry) {
                    $xmlWriter->startElement('url');
                    $xmlWriter->writeElement('loc', $entry->url);

                    if (isset($entry->priority)) {
                        $xmlWriter->writeElement('priority', $entry->priority);
                    }

                    if (isset($entry->changefreq)) {
                        $xmlWriter->writeElement('changefreq', $entry->changefreq);
                    }

                    if (isset($entry->lastmodified)) {
                        $xmlWriter->writeElement('lastmod', $entry->lastmodified->format(\DateTime::W3C));
                    }
                    $xmlWriter->endElement();
                }
            }
            $xmlWriter->endElement();
        }
        $xmlWriter->endDocument();
    }

    private function iterateTables()
    {
        $prio_info = .9;
        $prio_user = .8;
        $prio_table = .7;
        $prio_table_rev = .6;
        $prio_misc = .5;

        yield (object)[
            'url' => route('dash'),
            'priority' => 1,
        ];

        yield (object)[
            'url' => route('terms'),
            'priority' => $prio_info,
        ];

        yield (object)[
            'url' => route('faq'),
            'priority' => $prio_info,
        ];

        yield (object)[
            'url' => route('donate'),
            'priority' => $prio_info,
        ];

        yield (object)[
            'url' => route('privacy'),
            'priority' => $prio_info,
        ];

        yield (object)[
            'url' => route('login'),
            'priority' => $prio_misc,
        ];

        yield (object)[
            'url' => route('register'),
            'priority' => $prio_misc,
        ];

        foreach (User::all() as $user) {
            yield (object)[
                'url' => route('profile.view', $user->name),
                'lastmodified' => $user->updated_at,
                'priority' => $prio_user,
            ];
        }

        foreach (Table::all() as $table) {
            yield (object)[
                'url' => $table->viewRoute,
                'lastmodified' => $table->updated_at,
                'priority' => $prio_table,
            ];

            yield (object)[
                'url' => $table->revisionsRoute,
                'lastmodified' => $table->updated_at,
                'priority' => $prio_table_rev,
            ];
        }
    }
}