0.9.6.2 pair WebDAV migration with legacy fallback

include/nc_connector_webdav.inc.php

@@ -5,10 +5,89 @@ if (!defined('PHPWG_ROOT_PATH'))
 }
 
 /**
- * Create a disabled WebDAV-backed connector beside the existing local modes.
+ * Return the only existing local connector as migration fallback.
  *
- * This deliberately does not activate, migrate or modify any existing
+ * The 0.9.6.2 migration path is deliberately conservative: automatic pairing
- * connection. It only persists the data required for the parallel WebDAV path.
+ * only happens when there is exactly one local connection. Its enabled/state
+ * flags are never changed here, so the proven local path keeps running while
+ * WebDAV is introduced beside it.
+ */
+function bratonien_tools_nc_connector_single_local_fallback()
+{
+  bratonien_tools_nc_connector_ensure_table();
+  $table = bratonien_tools_nc_connector_table();
+  $result = pwg_query("SELECT id, enabled, takeover_state, config_json FROM `$table` WHERE adapter='local' ORDER BY id");
+  $rows = array();
+
+  while ($row = pwg_db_fetch_assoc($result))
+  {
+    $rows[] = $row;
+    if (count($rows) > 1) return null;
+  }
+
+  if (count($rows) !== 1) return null;
+
+  $row = $rows[0];
+  $config = json_decode((string)$row['config_json'], true);
+  if (!is_array($config)) $config = array();
+
+  return array(
+    'id'=>(int)$row['id'],
+    'enabled'=>(bool)$row['enabled'],
+    'takeover_state'=>(string)$row['takeover_state'],
+    'config'=>$config,
+  );
+}
+
+/**
+ * Link the new WebDAV connection with the single existing local connection.
+ *
+ * This is metadata only. The legacy connection is explicitly left untouched
+ * as an always-available fallback until a later, separately approved cutover.
+ */
+function bratonien_tools_nc_connector_pair_migration_fallback($webdav_id, array &$webdav_config, $now)
+{
+  $legacy = bratonien_tools_nc_connector_single_local_fallback();
+  if (!$legacy) return null;
+
+  $legacy_id = (int)$legacy['id'];
+  if ($legacy_id < 1 || $legacy_id === (int)$webdav_id) return null;
+
+  $webdav_config['migration'] = array(
+    'role'=>'webdav-primary-candidate',
+    'legacy_fallback_connection_id'=>$legacy_id,
+    'fallback_policy'=>'keep-running',
+    'paired_at'=>(string)$now,
+    'cutover_state'=>'parallel',
+  );
+
+  $legacy_config = $legacy['config'];
+  $legacy_config['migration'] = array(
+    'role'=>'legacy-fallback',
+    'webdav_successor_connection_id'=>(int)$webdav_id,
+    'fallback_policy'=>'keep-running',
+    'paired_at'=>(string)$now,
+    'cutover_state'=>'parallel',
+  );
+
+  $legacy_json = json_encode($legacy_config, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
+  if (!is_string($legacy_json))
+  {
+    throw new RuntimeException('Die bestehende Verbindung konnte nicht als Migrations-Fallback markiert werden.');
+  }
+
+  $table = bratonien_tools_nc_connector_table();
+  pwg_query("UPDATE `$table` SET config_json='".pwg_db_real_escape_string($legacy_json)."', updated='".pwg_db_real_escape_string((string)$now)."' WHERE id=".$legacy_id." LIMIT 1");
+
+  return $legacy_id;
+}
+
+/**
+ * Create a WebDAV-backed connector beside the existing local mode.
+ *
+ * Since 0.9.6.2, when exactly one local connection exists, the new WebDAV
+ * connection is automatically paired with it for migration. The local
+ * connection remains untouched and keeps running as fallback.
  */
 function bratonien_tools_nc_connector_create_webdav_placeholder_from_wizard()
 {
@@ -116,18 +195,36 @@ function bratonien_tools_nc_connector_create_webdav_placeholder_from_wizard()
   $id = (int)pwg_db_insert_id();
   if ($id < 1) throw new RuntimeException('Die WebDAV-Testverbindung konnte nicht eindeutig angelegt werden.');
 
-  $config['state_dir'] = '/var/lib/bratonien-tools/nc-connector/connection-'.$id;
+  try
-  $config['status_file'] = $config['state_dir'].'/connector-status.json';
+  {
-  $config_json = json_encode($config, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
+    $config['state_dir'] = '/var/lib/bratonien-tools/nc-connector/connection-'.$id;
-  if (!is_string($config_json))
+    $config['status_file'] = $config['state_dir'].'/connector-status.json';
+    $legacy_fallback_id = bratonien_tools_nc_connector_pair_migration_fallback($id, $config, $now);
+
+    $config_json = json_encode($config, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
+    if (!is_string($config_json))
+    {
+      throw new RuntimeException('Die WebDAV-Testverbindung konnte nach dem Anlegen nicht serialisiert werden.');
+    }
+    pwg_query("UPDATE `$table` SET config_json='".pwg_db_real_escape_string($config_json)."' WHERE id=".$id." LIMIT 1");
+  }
+  catch (Throwable $e)
   {
     pwg_query("DELETE FROM `$table` WHERE id=".$id." LIMIT 1");
-    throw new RuntimeException('Die WebDAV-Testverbindung konnte nach dem Anlegen nicht serialisiert werden.');
+    throw $e;
+  }
+
+  if ($legacy_fallback_id !== null)
+  {
+    return array(
+      'connection_id'=>$id,
+      'legacy_fallback_connection_id'=>$legacy_fallback_id,
+      'message'=>'WebDAV-Verbindung wurde parallel angelegt. Die bestehende lokale Verbindung #'.$legacy_fallback_id.' bleibt unverändert als laufender Fallback erhalten.',
+    );
   }
-  pwg_query("UPDATE `$table` SET config_json='".pwg_db_real_escape_string($config_json)."' WHERE id=".$id." LIMIT 1");
 
   return array(
     'connection_id'=>$id,
-    'message'=>'Parallele WebDAV-Testverbindung wurde deaktiviert angelegt. Bestehende Verbindungen blieben unverändert.',
+    'message'=>'Parallele WebDAV-Verbindung wurde angelegt. Bestehende Verbindungen blieben unverändert.',
   );
 }