From 37716dc58e40a9fe3cf058fed7edfba2af552dcb Mon Sep 17 00:00:00 2001
From: Paul Holden <paulh@moodle.com>
Date: Wed, 5 May 2021 09:30:30 +0100
Subject: [PATCH] MDL-71050 h5p: account for parent languages retrieving
 translations.

Take account of parent languages when requesting given library
translation. For example if we are currently using "de_kids" as the
current language, we need to recurse each language pack looking for
a matching H5P translation ("de_kids" -> "de_du" -> "de").
---
 h5p/ajax.php                     |  4 +-
 h5p/classes/editor_framework.php | 76 +++++++++++++++++++++++---------
 2 files changed, 57 insertions(+), 23 deletions(-)

diff --git a/h5p/ajax.php b/h5p/ajax.php
index b5d7638be00..915c14538bb 100644
--- a/h5p/ajax.php
+++ b/h5p/ajax.php
@@ -55,7 +55,9 @@ switch ($action) {
         $major = optional_param('majorVersion', 0, PARAM_INT);
         $minor = optional_param('minorVersion', 0, PARAM_INT);
 
-        $language = optional_param('default-language', null, PARAM_ALPHA);
+        // Normalise Moodle language using underscore, as opposed to H5P which uses dash.
+        $language = optional_param('default-language', null, PARAM_RAW);
+        $language = clean_param(str_replace('-', '_', $language), PARAM_LANG);
 
         if (!empty($name)) {
             $editor->ajax->action(H5PEditorEndpoints::SINGLE_LIBRARY, $name,
diff --git a/h5p/classes/editor_framework.php b/h5p/classes/editor_framework.php
index 587b83490f5..8835aea06c4 100644
--- a/h5p/classes/editor_framework.php
+++ b/h5p/classes/editor_framework.php
@@ -39,6 +39,59 @@ use stdClass;
  */
 class editor_framework implements H5peditorStorage {
 
+    /**
+     * Retrieve library language file from file storage. Note that parent languages will also be checked until a matching
+     * record is found (e.g. "de_kids" -> "de_du" -> "de")
+     *
+     * @param string $name
+     * @param int $major
+     * @param int $minor
+     * @param string $lang
+     * @return stdClass|bool Translation record if available, false otherwise
+     */
+    private function get_language_record(string $name, int $major, int $minor, string $lang) {
+        global $DB;
+
+        $params = [
+            file_storage::COMPONENT,
+            file_storage::LIBRARY_FILEAREA,
+        ];
+        $sqllike = $DB->sql_like('f.filepath', '?');
+        $params[] = '%language%';
+
+        $sql = "SELECT hl.id, f.pathnamehash
+                  FROM {h5p_libraries} hl
+             LEFT JOIN {files} f
+                    ON hl.id = f.itemid AND f.component = ? AND f.filearea = ? AND $sqllike
+                 WHERE ((hl.machinename = ? AND hl.majorversion = ? AND hl.minorversion = ?)
+                   AND f.filename = ?)
+              ORDER BY hl.patchversion DESC";
+
+        $params[] = $name;
+        $params[] = $major;
+        $params[] = $minor;
+        $params[] = $lang.'.json';
+
+        // Add translations, based initially on the given H5P language code. If missing then recurse language dependencies
+        // until we find a matching H5P language file.
+        $result = $DB->get_record_sql($sql, $params);
+        if ($result === false) {
+
+            // Normalise Moodle language using underscore, as opposed to H5P which uses dash.
+            $moodlelanguage = str_replace('-', '_', $lang);
+
+            $dependencies = get_string_manager()->get_language_dependencies($moodlelanguage);
+
+            // If current language has a dependency, then request it.
+            if (count($dependencies) > 1) {
+                $parentlanguage = str_replace('_', '-', $dependencies[count($dependencies) - 2]);
+                $result = $this->get_language_record($name, $major, $minor, $parentlanguage);
+            }
+        }
+
+        return $result;
+    }
+
     /**
      * Load language file(JSON).
      * Used to translate the editor fields(title, description etc.)
@@ -51,7 +104,6 @@ class editor_framework implements H5peditorStorage {
      * @return string|boolean Translation in JSON format if available, false otherwise
      */
     public function getLanguage($name, $major, $minor, $lang) {
-        global $DB;
 
         // Check if this information has been saved previously into the cache.
         $langcache = \cache::make('core', 'h5p_content_type_translations');
@@ -74,27 +126,7 @@ class editor_framework implements H5peditorStorage {
         }
 
         // Get the language file for this library.
-        $params = [
-            file_storage::COMPONENT,
-            file_storage::LIBRARY_FILEAREA,
-        ];
-        $sqllike = $DB->sql_like('f.filepath', '?');
-        $params[] = '%language%';
-
-        $sql = "SELECT hl.id, f.pathnamehash
-                  FROM {h5p_libraries} hl
-             LEFT JOIN {files} f
-                    ON hl.id = f.itemid AND f.component = ? AND f.filearea = ? AND $sqllike
-                 WHERE ((hl.machinename = ? AND hl.majorversion = ? AND hl.minorversion = ?)
-                   AND f.filename = ?)
-              ORDER BY hl.patchversion DESC";
-        $params[] = $name;
-        $params[] = $major;
-        $params[] = $minor;
-        $params[] = $lang.'.json';
-
-        $result = $DB->get_record_sql($sql, $params);
-
+        $result = $this->get_language_record($name, $major, $minor, $lang);
         if (empty($result)) {
             // Save the fact that there is no translation into the cache.
             // The cache API cannot handle setting a literal `false` value so conver to `null` instead.