refactor: consolidate rewrite/plugin optimizations

src/Discovery/AlternateLinkHandler.php

@@ -7,6 +7,7 @@
 
 namespace MarkdownAlternate\Discovery;
 
+use MarkdownAlternate\PostTypeSupport;
 use MarkdownAlternate\Router\UrlConverter;
 
 /**
@@ -26,30 +27,6 @@ public function register(): void {
         add_action( 'wp_head', [ $this, 'output_alternate_link' ], 5 );
     }
 
-    /**
-     * Get supported post types for markdown output.
-     *
-     * Returns an array of post types that can be served as markdown.
-     * Developers can extend this via the 'markdown_alternate_supported_post_types' filter.
-     *
-     * @return array List of supported post type names.
-     */
-    private function get_supported_post_types(): array {
-        $default_types = [ 'post', 'page' ];
-        return apply_filters( 'markdown_alternate_supported_post_types', $default_types );
-    }
-
-    /**
-     * Check if a post type is supported for markdown output.
-     *
-     * @param string $post_type The post type to check.
-     * @return bool True if supported, false otherwise.
-     */
-    private function is_supported_post_type( string $post_type ): bool {
-        return in_array( $post_type, $this->get_supported_post_types(), true );
-    }
-
-
     /**
      * Output alternate link tag for markdown version.
      *
@@ -70,13 +47,13 @@ public function output_alternate_link(): void {
             return;
         }
 
-        // Only for published posts.
+        // Only for published content.
         if ( get_post_status( $post ) !== 'publish' ) {
             return;
         }
 
         // Only for supported post types.
-        if ( ! $this->is_supported_post_type( $post->post_type ) ) {
+        if ( ! PostTypeSupport::is_supported( $post->post_type ) ) {
             return;
         }
 

src/Plugin.php

@@ -67,7 +67,8 @@ private function __construct() {
      * @return void
      */
     public static function activate(): void {
-        RewriteHandler::register_rules();
+        $handler = new RewriteHandler();
+        $handler->add_rewrite_rules();
         flush_rewrite_rules();
     }
 

src/PostTypeSupport.php

@@ -0,0 +1,40 @@
+<?php
+/**
+ * Post type support utility for markdown output.
+ *
+ * @package MarkdownAlternate
+ */
+
+namespace MarkdownAlternate;
+
+/**
+ * Shared utility for post type validation.
+ *
+ * Provides a single source of truth for determining which post types
+ * support markdown output.
+ */
+class PostTypeSupport {
+
+	/**
+	 * Get supported post types for markdown output.
+	 *
+	 * Returns an array of post types that can be served as markdown.
+	 * Developers can extend this via the 'markdown_alternate_supported_post_types' filter.
+	 *
+	 * @return array List of supported post type names.
+	 */
+	public static function get_supported_types(): array {
+		$default_types = [ 'post', 'page' ];
+		return apply_filters( 'markdown_alternate_supported_post_types', $default_types );
+	}
+
+	/**
+	 * Check if a post type is supported for markdown output.
+	 *
+	 * @param string $post_type The post type to check.
+	 * @return bool True if supported, false otherwise.
+	 */
+	public static function is_supported( string $post_type ): bool {
+		return in_array( $post_type, self::get_supported_types(), true );
+	}
+}

src/Router/RewriteHandler.php

@@ -9,6 +9,7 @@
 
 use WP_Post;
 use MarkdownAlternate\Output\ContentRenderer;
+use MarkdownAlternate\PostTypeSupport;
 
 /**
  * Handles URL rewriting and markdown request processing.
@@ -22,6 +23,13 @@ class RewriteHandler {
      */
     private ?WP_Post $markdown_post = null;
 
+    /**
+     * Cached ContentRenderer instance.
+     *
+     * @var ContentRenderer|null
+     */
+    private ?ContentRenderer $renderer = null;
+
     /**
      * Register all hooks for URL routing.
      *
@@ -143,7 +151,7 @@ public function parse_markdown_url(\WP $wp): void {
             return;
         }
 
-        if (!$this->is_supported_post_type($post->post_type)) {
+        if (!PostTypeSupport::is_supported($post->post_type)) {
             return;
         }
 
@@ -170,26 +178,55 @@ public function add_query_vars(array $vars): array {
     }
 
     /**
-     * Get supported post types for markdown output.
+     * Get cached ContentRenderer instance.
      *
-     * Returns an array of post types that can be served as markdown.
-     * Developers can extend this via the 'markdown_alternate_supported_post_types' filter.
+     * @return ContentRenderer The renderer instance.
+     */
+    private function get_renderer(): ContentRenderer {
+        if ($this->renderer === null) {
+            $this->renderer = new ContentRenderer();
+        }
+
+        return $this->renderer;
+    }
+
+    /**
+     * Validate post for markdown output.
      *
-     * @return array List of supported post type names.
+     * @param WP_Post $post The post to validate.
+     * @return bool True if valid for markdown output, false otherwise.
      */
-    private function get_supported_post_types(): array {
-        $default_types = ['post', 'page'];
-        return apply_filters('markdown_alternate_supported_post_types', $default_types);
+    private function validate_post_for_markdown(WP_Post $post): bool {
+        if (!PostTypeSupport::is_supported($post->post_type)) {
+            return false;
+        }
+
+        if (get_post_status($post) !== 'publish') {
+            return false;
+        }
+
+        return true;
     }
 
     /**
-     * Check if a post type is supported for markdown output.
+     * Serve markdown response for a post.
      *
-     * @param string $post_type The post type to check.
-     * @return bool True if supported, false otherwise.
+     * @param WP_Post $post The post to serve.
+     * @return void
      */
-    private function is_supported_post_type(string $post_type): bool {
-        return in_array($post_type, $this->get_supported_post_types(), true);
+    private function serve_markdown_response(WP_Post $post): void {
+        if (post_password_required($post)) {
+            status_header(403);
+            header('Content-Type: text/plain; charset=UTF-8');
+            echo 'This content is password protected.';
+            exit;
+        }
+
+        $markdown = $this->get_renderer()->render($post);
+
+        $this->set_response_headers($post, $markdown);
+        echo $markdown;
+        exit;
     }
 
     /**
@@ -201,55 +238,29 @@ private function is_supported_post_type(string $post_type): bool {
      * @return void
      */
     public function handle_format_parameter(): void {
-        // Skip if already a markdown request (URL wins over query parameter)
         if (get_query_var('markdown_request')) {
             return;
         }
 
-        // Check for format=markdown query parameter (case-sensitive, strict equality)
-        $format = get_query_var('format');
-        if ($format !== 'markdown') {
+        if (get_query_var('format') !== 'markdown') {
             return;
         }
 
-        // Only for singular content
         if (!is_singular()) {
             return;
         }
 
-        // Get the queried object
         $post = get_queried_object();
 
-        // Validate post exists and is a WP_Post
         if (!$post instanceof WP_Post) {
             return;
         }
 
-        // Check post type - only serve supported post types
-        if (!$this->is_supported_post_type($post->post_type)) {
-            return;
-        }
-
-        // Check post status - only serve published posts
-        if (get_post_status($post) !== 'publish') {
+        if (!$this->validate_post_for_markdown($post)) {
             return;
         }
 
-        // Check password protection
-        if (post_password_required($post)) {
-            status_header(403);
-            header('Content-Type: text/plain; charset=UTF-8');
-            echo 'This content is password protected.';
-            exit;
-        }
-
-        // Render and serve the markdown content
-        $renderer = new ContentRenderer();
-        $markdown = $renderer->render($post);
-
-        $this->set_response_headers($post, $markdown);
-        echo $markdown;
-        exit;
+        $this->serve_markdown_response($post);
     }
 
     /**
@@ -260,59 +271,35 @@ public function handle_format_parameter(): void {
      * @return void
      */
     public function handle_markdown_request(): void {
-        // Check if this is a markdown request
         if (!get_query_var('markdown_request')) {
             return;
         }
 
-        // Get the request URI
         $request_uri = $_SERVER['REQUEST_URI'] ?? '';
 
-        // Enforce lowercase .md extension - let WP 404 if wrong case
-        if (!preg_match('/\.md$/', $request_uri) && preg_match('/\.md$/i', $request_uri)) {
+        if (
+            !preg_match('/\.md$/', $request_uri) &&
+            preg_match('/\.md$/i', $request_uri)
+        ) {
             return;
         }
 
-        // Handle trailing slash redirect: /post-slug.md/ -> /post-slug.md
-        if (preg_match('/\.md\/$/', $request_uri)) {
-            $redirect_url = rtrim($request_uri, '/');
-            wp_redirect($redirect_url, 301);
+        if (str_ends_with($request_uri, '.md/')) {
+            wp_redirect(rtrim($request_uri, '/'), 301);
             exit;
         }
 
-        // Get post - use cached post from parse_markdown_url (Nginx) or queried object (Apache)
         $post = $this->markdown_post ?? get_queried_object();
 
-        // Validate post exists and is a WP_Post
         if (!$post instanceof WP_Post) {
             return;
         }
 
-        // Check post type - only serve supported post types
-        if (!$this->is_supported_post_type($post->post_type)) {
-            return;
-        }
-
-        // Check post status - only serve published posts
-        if (get_post_status($post) !== 'publish') {
+        if (!$this->validate_post_for_markdown($post)) {
             return;
         }
 
-        // Check password protection
-        if (post_password_required($post)) {
-            status_header(403);
-            header('Content-Type: text/plain; charset=UTF-8');
-            echo 'This content is password protected.';
-            exit;
-        }
-
-        // Render and serve the markdown content
-        $renderer = new ContentRenderer();
-        $markdown = $renderer->render($post);
-
-        $this->set_response_headers($post, $markdown);
-        echo $markdown;
-        exit;
+        $this->serve_markdown_response($post);
     }
 
     /**
@@ -429,15 +416,4 @@ private function get_current_canonical_url(): ?string {
         return null;
     }
 
-    /**
-     * Register rewrite rules statically.
-     *
-     * Used by activation hook to ensure rules are registered before flush.
-     *
-     * @return void
-     */
-    public static function register_rules(): void {
-        $handler = new self();
-        $handler->add_rewrite_rules();
-    }
 }