Polymorphic refactor + improvements to select sql rewriting

pg4wp/rewriters/AbstractSQLRewriter.php

@@ -0,0 +1,26 @@
+<?php
+
+abstract class AbstractSQLRewriter
+{
+    protected string $originalSQL;
+
+    public function __construct(string $sql)
+    {
+        $this->originalSQL = $sql;
+    }
+
+    abstract public function rewrite(): string;
+
+    public function original(): string
+    {
+        return $this->originalSQL;
+    }
+
+    public function type(): string
+    {
+        // Get the called class name and remove the "SQLRewriter" suffix to get the SQL type
+        $className = get_called_class();
+        $type = str_replace('SQLRewriter', '', $className);
+        return $type;
+    }
+}