Fix playlist sync db issue (#1366)

* Enhance playlist migration by enforcing foreign key constraints and ensuring non-nullable columns

* make sure the playlist table has no null config_id

* Draft: check for invalid records!

* add more error handling

* try different fkey name

* try separate db query for the same fkey

lib/Helpers/PlaylistMigration.php

@@ -19,17 +19,21 @@ class PlaylistMigration
     {
         $db = DBManager::get();
 
+        // Default opencast server if playlist belongs to no opencast server
+        $default_config_id = \Config::get()->OPENCAST_DEFAULT_SERVER;
+
+        try {
             // Migrate existing playlists to Opencast
             $playlists = Playlists::findBySQL('service_playlist_id IS NULL');
 
             // Try three times
             $tries = 0;
-        while (!empty($playlists) && $tries < 3) {
+            while (!empty($playlists) && $tries < 10) {
                 foreach ($playlists as $playlist) {
-                $config_id = $playlist->config_id;
+                    $config_id = $playlist->config_id ?? null;
                     if (empty($config_id)) {
                         // Default opencast server if playlist belongs to no opencast server
-                    $config_id = \Config::get()->OPENCAST_DEFAULT_SERVER;
+                        $config_id = $default_config_id;
                     }
 
                     // Get playlist videos
@@ -67,12 +71,57 @@ class PlaylistMigration
                 $tries++;
             }
 
+            // What is the point of letting the process continue if there are still playlists with null service_playlist_id of duplicated service_playlist_ids?
+            $duplicate_service_playlist_ids = $db->query(
+                "SELECT service_playlist_id, COUNT(*) as count
+                FROM oc_playlist
+                WHERE service_playlist_id IS NOT NULL
+                GROUP BY service_playlist_id
+                HAVING count > 1"
+            )->fetchAll(\PDO::FETCH_ASSOC);
+
+            if (!empty($playlists) || !empty($duplicate_service_playlist_ids)) {
+                $message = "Migration failed due to invalid data records:\n";
+                if (!empty($playlists)) {
+                    $message .= "Playlists with null service_playlist_id:\n";
+                    foreach ($playlists as $playlist) {
+                        $message .= "Playlist ID: {$playlist->id}\n";
+                    }
+                }
+                if (!empty($duplicate_service_playlist_ids)) {
+                    $message .= "Duplicate service_playlist_ids:\n";
+                    foreach ($duplicate_service_playlist_ids as $record) {
+                        $message .= "Service Playlist ID: {$record['service_playlist_id']}, Count: {$record['count']}\n";
+                    }
+                }
+                throw new \Exception($message);
+            }
+
+            // We need another step to make sure config id is set and it is not null before altering the table with not-null config_id.
+            $null_config_playlists = Playlists::findBySQL('config_id IS NULL');
+
+            while (!empty($null_config_playlists)) {
+                foreach ($null_config_playlists as $null_config_playlist) {
+                    // Store config id with default config id.
+                    $null_config_playlist->config_id = $default_config_id;
+                    $null_config_playlist->store();
+                }
+                $null_config_playlists = Playlists::findBySQL('config_id IS NULL');
+            }
+
             // Forbid playlist without related oc playlist
+            // First drop foreign key constraint
+            $db->exec('ALTER TABLE `oc_playlist` DROP FOREIGN KEY `oc_playlist_ibfk_1`');
+            // Then change column to not null
             $db->exec('ALTER TABLE `oc_playlist`
                 CHANGE COLUMN `config_id` `config_id` int NOT NULL,
                 CHANGE COLUMN `service_playlist_id` `service_playlist_id` varchar(64) UNIQUE NOT NULL'
             );
-
+            // Then add foreign key constraint again
+            $db->exec('ALTER TABLE `oc_playlist`
+                ADD FOREIGN KEY `oc_playlist_ibfk_1` (`config_id`) REFERENCES `oc_config` (`id`)
+                ON DELETE RESTRICT ON UPDATE RESTRICT'
+            );
             // Forbid playlist video without related oc playlist entry
             $db->exec('ALTER TABLE `oc_playlist_video`
                 CHANGE COLUMN `service_entry_id` `service_entry_id` int NOT NULL'
@@ -93,6 +142,9 @@ class PlaylistMigration
                 $scheduler->schedulePeriodic($task_id, -10);  // negative value means "every x minutes"
                 \CronjobSchedule::findByTask_id($task_id)[0]->activate();
             }
+        } catch (\Throwable $th) {
+            throw new \Exception('Migration fehlgeschlagen: ' . $th->getMessage());
+        }
     }
 
         /**