added wiki.php as redirection script, fixes #4996

Closes #4996

Merge request studip/studip!3749

public/wiki.php

+<?php
+/**
+ * wiki.php
+ *
+ * This script is needed to redirect wiki pages referenced by an URL to the old wiki
+ * (before Stud.IP 5.5) to the controller of the new wiki (Stud.IP 5.5 and newer).
+ *
+ * @author      Jan-Hendrik Willms <tleilax+studip@gmail.com>
+ * @author      Moritz Strohm <strohm@data-quest.de>
+ * @license     http://www.gnu.org/licenses/gpl-2.0.html GPL version 2
+ * @category    Stud.IP
+ * @since       5.5
+ */
+
+// Set up a minimal Stud.IP environment:
+require_once __DIR__ . '/../lib/bootstrap.php';
+URLHelper::setBaseUrl($GLOBALS['ABSOLUTE_URI_STUDIP']);
+
+// Set exception handler which outputs the message of the exception.
+// In case the Stud.IP is in development mode, the stack trace
+// is also printed before halting execution.
+set_exception_handler(function (Throwable $exception) {
+    header('Content-Type: text/plain');
+    echo $exception->getMessage();
+    if (Studip\ENV === 'development') {
+        echo "\n" . $exception->getTraceAsString();
+    }
+    die;
+});
+
+// Handle URL parameters:
+$course_id = Request::option('cid');
+$keyword   = Request::get('keyword');
+$version   = Request::int('version');
+if (!$course_id) {
+    // Invalid wiki page.
+    die(sprintf(_('Fehlender URL-Parameter: %s'), 'cid'));
+}
+
+// Load the wiki page or a version of it:
+$page         = null;
+$page_version = null;
+
+if (!$keyword || $keyword === 'WikiWikiWeb') {
+    // Load the start page for the course:
+    $page_id = CourseConfig::get($course_id)->getValue('WIKI_STARTPAGE_ID');
+    $load_newest_version = true;
+    if ($version) {
+        // Check if the requested version is the newest version.
+        // In that case, the wiki_pages table instead of the wiki_versions
+        // table must be used to get the correct version of the page.
+        $newest_version = 1 + WikiVersion::countByPage_id($page_id);
+
+        $load_newest_version = $version === $newest_version;
+    }
+    if ($load_newest_version) {
+        // Load the newest version:
+        $page = WikiPage::find($page_id);
+    } else {
+        // Load the requested version:
+        $page_version = WikiVersion::findOneBySQL(
+            '`page_id` = :page_id
+             ORDER BY `mkdate` ASC
+             LIMIT 1 OFFSET :version',
+            [
+                'page_id' => $page_id,
+                'version' => $version - 1
+            ]
+        );
+    }
+} else {
+    // Load the page by its keyword and course-ID:
+    $load_newest_version = true;
+    if ($version) {
+        // Check if the requested version is the newest version.
+        // In that case, the wiki_pages table instead of the wiki_versions
+        // table must be used to get the correct version of the page.
+        $newest_version = 1 + WikiVersion::countBySql(
+            'JOIN `wiki_pages` USING (`page_id`)
+             WHERE `wiki_pages`.`range_id` = :course_id AND `wiki_pages`.`name` = :keyword',
+            [
+                'course_id' => $course_id,
+                'keyword' => $keyword
+            ]
+        );
+        $load_newest_version = $version === $newest_version;
+    }
+
+    if ($load_newest_version) {
+        // Load the newest version:
+        $page = WikiPage::findOneBySQL(
+            '`range_id` = :course_id AND `name` = :keyword',
+            [
+                'course_id' => $course_id,
+                'keyword' => $keyword
+            ]
+        );
+    } else {
+        // Load the requested version:
+        $page_version = WikiVersion::findOneBySQL(
+            'JOIN `wiki_pages` USING (`page_id`)
+             WHERE `wiki_pages`.`range_id` = :course_id AND `wiki_pages`.`name` = :keyword
+             ORDER BY `wiki_versions`.`mkdate` ASC
+             LIMIT 1 OFFSET :version',
+            [
+                'course_id' => $course_id,
+                'keyword'   => $keyword,
+                'version'   => $version - 1
+            ]
+        );
+    }
+}
+if (!$page && !$page_version) {
+    // Page not found:
+    die(sprintf(_('Die Wikiseite mit dem Schlagwort "%s" wurde nicht gefunden.'), $keyword));
+}
+
+// Everything went well: Redirect permanently to the new wiki page.
+// Assume that the optional version parameter is not set and redirect to the newest
+// version of the wiki page, which should be the usual case.
+$url = URLHelper::getURL('dispatch.php/course/wiki/page/' . $page->id, ['cid' => $course_id]);
+if ($page_version) {
+    //Redirect to the specific version of the wiki page instead of the newest version:
+    $url = URLHelper::getURL('dispatch.php/course/wiki/version/' . $page_version->id, ['cid' => $course_id]);
+}
+
+header('Location: ' . $url, true, 301);