Refactor fragile SQLite regex rewrites into driver-aware query methods

Move the ON DUPLICATE KEY UPDATE and UPDATE...AS alias SQL rewrites out
of Database::rewriteForSQLite() and into Tag::createNew() and
Tag::recount() as driver-aware branches via a new Database::getDriver()
method. This keeps dialect-specific SQL explicit at the call site rather
than buried in fragile regex transforms.

Also fix Tag::getAlbums() and Tag::getPeople() failing on SQLite when
id_parent is NULL by adding an IS NULL fallback for root-level queries.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

models/Database.php

@@ -73,36 +73,18 @@ class Database
 		}, 0);
 	}
 
+	public function getDriver()
+	{
+		return $this->driver;
+	}
+
 	private function rewriteForSQLite($sql)
 	{
 		// REPLACE INTO → INSERT OR REPLACE INTO
 		$sql = preg_replace('/\bREPLACE\s+INTO\b/i', 'INSERT OR REPLACE INTO', $sql);
 
-		// ON DUPLICATE KEY UPDATE → ON CONFLICT(slug) DO UPDATE SET
-		// When present, strip INSERT IGNORE down to INSERT (OR IGNORE conflicts with ON CONFLICT).
-		if (preg_match('/\bON\s+DUPLICATE\s+KEY\s+UPDATE\b/i', $sql))
-		{
-			$sql = preg_replace('/\bINSERT\s+IGNORE\s+INTO\b/i', 'INSERT INTO', $sql);
-			$sql = preg_replace(
-				'/\bON\s+DUPLICATE\s+KEY\s+UPDATE\s+(.+)/i',
-				'ON CONFLICT(slug) DO UPDATE SET $1',
-				$sql
-			);
-		}
-		else
-		{
 		// INSERT IGNORE INTO → INSERT OR IGNORE INTO
 		$sql = preg_replace('/\bINSERT\s+IGNORE\s+INTO\b/i', 'INSERT OR IGNORE INTO', $sql);
-		}
-
-		// UPDATE table AS alias SET ... → UPDATE table SET ... (with alias replaced by table name)
-		if (preg_match('/\bUPDATE\s+(\w+)\s+AS\s+(\w+)\s+SET\b/i', $sql, $m))
-		{
-			$table = $m[1];
-			$alias = $m[2];
-			$sql = preg_replace('/\bUPDATE\s+\w+\s+AS\s+\w+\s+SET\b/i', "UPDATE $table SET", $sql);
-			$sql = preg_replace('/\b' . preg_quote($alias, '/') . '\.(\w+)\b/', "$table.$1", $sql);
-		}
 
 		// LIMIT :offset, :limit → LIMIT :limit OFFSET :offset
 		$sql = preg_replace(

models/Tag.php

@@ -122,10 +122,12 @@ class Tag
 
 	public static function getAlbums($id_parent = 0, $offset = 0, $limit = 24, $return_format = 'array')
 	{
+		$parent_clause = empty($id_parent) ? '(id_parent = :id_parent OR id_parent IS NULL)' : 'id_parent = :id_parent';
+
 		$rows = Registry::get('db')->queryAssocs('
 			SELECT *
 			FROM tags
-			WHERE id_parent = :id_parent AND kind = :kind
+			WHERE ' . $parent_clause . ' AND kind = :kind
 			ORDER BY tag ASC
 			LIMIT :offset, :limit',
 			[
@@ -163,10 +165,12 @@ class Tag
 
 	public static function getPeople($id_parent = 0, $offset = 0, $limit = 24, $return_format = 'array')
 	{
+		$parent_clause = empty($id_parent) ? '(id_parent = :id_parent OR id_parent IS NULL)' : 'id_parent = :id_parent';
+
 		$rows = Registry::get('db')->queryAssocs('
 			SELECT *
 			FROM tags
-			WHERE id_parent = :id_parent AND kind = :kind
+			WHERE ' . $parent_clause . ' AND kind = :kind
 			ORDER BY tag ASC
 			LIMIT :offset, :limit',
 			[
@@ -249,7 +253,21 @@ class Tag
 
 	public static function recount(array $id_tags = [])
 	{
-		return Registry::get('db')->query('
+		$db = Registry::get('db');
+
+		if ($db->getDriver() === 'sqlite')
+		{
+			return $db->query('
+				UPDATE tags SET count = (
+					SELECT COUNT(*)
+					FROM `assets_tags` AS at
+					WHERE at.id_tag = tags.id_tag
+				)' . (!empty($id_tags) ? '
+				WHERE tags.id_tag IN(@id_tags)' : ''),
+				['id_tags' => $id_tags]);
+		}
+
+		return $db->query('
 			UPDATE tags AS t SET count = (
 				SELECT COUNT(*)
 				FROM `assets_tags` AS at
@@ -272,6 +290,18 @@ class Tag
 		if (!isset($data['count']))
 			$data['count'] = 0;
 
+		if ($db->getDriver() === 'sqlite')
+		{
+			$res = $db->query('
+				INSERT INTO tags
+				(id_parent, tag, slug, kind, description, count)
+				VALUES
+				(:id_parent, :tag, :slug, :kind, :description, :count)
+				ON CONFLICT(slug) DO UPDATE SET count = count + 1',
+				$data);
+		}
+		else
+		{
 			$res = $db->query('
 				INSERT IGNORE INTO tags
 				(id_parent, tag, slug, kind, description, count)
@@ -279,6 +309,7 @@ class Tag
 				(:id_parent, :tag, :slug, :kind, :description, :count)
 				ON DUPLICATE KEY UPDATE count = count + 1',
 				$data);
+		}
 
 		if (!$res)
 			throw new Exception('Could not create the requested tag.');