From eb84bb827446ba8830bced69622c8083700fc451 Mon Sep 17 00:00:00 2001
From: Vladimir Bryzgalov <vladimir.bryzgalov@gmail.com>
Date: Sat, 16 May 2026 20:03:04 +0500
Subject: [PATCH] feat(wpmc S4): Redirect class 301s on page_unic clone access

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 includes/class-redirect.php |  71 ++++++++++++++++++++++++
 tests/RedirectTest.php      | 104 ++++++++++++++++++++++++++++++++++++
 2 files changed, 175 insertions(+)
 create mode 100644 includes/class-redirect.php
 create mode 100644 tests/RedirectTest.php

diff --git a/includes/class-redirect.php b/includes/class-redirect.php
new file mode 100644
index 0000000..299eec1
--- /dev/null
+++ b/includes/class-redirect.php
@@ -0,0 +1,71 @@
+<?php
+declare(strict_types=1);
+
+namespace WPMultiCity;
+
+final class Redirect
+{
+    public static function register(): void
+    {
+        \add_action('wp', [self::class, 'handle'], 9998);
+    }
+
+    public static function handle(): void
+    {
+        if (\is_admin()) {
+            return;
+        }
+        if (\defined('DOING_AJAX') && \DOING_AJAX) {
+            return;
+        }
+        $main = Helpers::main_town_slug();
+        if ($main === null) {
+            return;
+        }
+        global $post;
+        if (!isset($post->ID)) {
+            return;
+        }
+        $current_page_id = (int) $post->ID;
+        if (!\function_exists('get_field')) {
+            return;
+        }
+        $page_unic = \get_field('page_unic', 'option');
+        if (!is_array($page_unic)) {
+            return;
+        }
+        $request_uri = $_SERVER['REQUEST_URI'] ?? '/';
+        foreach ($page_unic as $row) {
+            if (!is_array($row)) {
+                continue;
+            }
+            if ((int) ($row['page_new'] ?? 0) !== $current_page_id) {
+                continue;
+            }
+            $town_term_id = (int) ($row['town'] ?? 0);
+            if (!$town_term_id) {
+                continue;
+            }
+            $term = \get_term_by('id', $town_term_id, 'town');
+            if (!($term instanceof \WP_Term) || $term->slug === '' || $term->slug === $main) {
+                continue;
+            }
+            $town_slug = $term->slug;
+            if (preg_match('#^/' . preg_quote($town_slug, '#') . '(/|$)#', $request_uri)) {
+                return;
+            }
+            $orig_id = (int) ($row['page_old'] ?? 0);
+            if (!$orig_id) {
+                return;
+            }
+            $orig_permalink = \get_permalink($orig_id);
+            if (!is_string($orig_permalink) || $orig_permalink === '') {
+                return;
+            }
+            $path_only = Helpers::remove_domain_link($orig_permalink);
+            $redirect_to = '/' . $town_slug . $path_only;
+            \wp_safe_redirect($redirect_to, 301);
+            exit;
+        }
+    }
+}
diff --git a/tests/RedirectTest.php b/tests/RedirectTest.php
new file mode 100644
index 0000000..2515621
--- /dev/null
+++ b/tests/RedirectTest.php
@@ -0,0 +1,104 @@
+<?php
+declare(strict_types=1);
+
+namespace WPMultiCity\Tests;
+
+use WPMultiCity\Redirect;
+
+final class RedirectTest extends TestCase
+{
+    public function test_register_attaches_wp_action_at_priority_9998(): void
+    {
+        Redirect::register();
+
+        self::assertSame(
+            9998,
+            has_action('wp', [Redirect::class, 'handle']),
+            'Redirect::register() must hook wp action at priority 9998'
+        );
+    }
+
+    public function test_handle_skips_when_current_town_equals_main(): void
+    {
+        \Brain\Monkey\Functions\expect('wp_safe_redirect')->never();
+        \Brain\Monkey\Functions\when('is_admin')->justReturn(false);
+        $_SERVER['REQUEST_URI'] = '/spb/about/';
+        \Brain\Monkey\Functions\when('get_terms')->justReturn([10 => 'spb']);
+        \Brain\Monkey\Functions\when('get_field')->alias(function ($name) {
+            if ($name === 'main_town_slug') return 'spb';
+            return false;
+        });
+
+        Redirect::handle();
+
+        self::assertTrue(true);
+    }
+
+    public function test_handle_skips_when_post_not_set(): void
+    {
+        \Brain\Monkey\Functions\expect('wp_safe_redirect')->never();
+        \Brain\Monkey\Functions\when('is_admin')->justReturn(false);
+        $_SERVER['REQUEST_URI'] = '/about/';
+        \Brain\Monkey\Functions\when('get_terms')->justReturn([11 => 'tyumen']);
+        \Brain\Monkey\Functions\when('get_field')->alias(function ($name) {
+            if ($name === 'main_town_slug') return 'spb';
+            return false;
+        });
+        unset($GLOBALS['post']);
+
+        Redirect::handle();
+
+        self::assertTrue(true);
+    }
+
+    public function test_handle_skips_when_url_already_has_town_prefix(): void
+    {
+        \Brain\Monkey\Functions\expect('wp_safe_redirect')->never();
+        \Brain\Monkey\Functions\when('is_admin')->justReturn(false);
+        $_SERVER['REQUEST_URI'] = '/tyumen/about/';
+        \Brain\Monkey\Functions\when('get_terms')->justReturn([11 => 'tyumen']);
+        \Brain\Monkey\Functions\when('get_field')->alias(function ($name) {
+            if ($name === 'main_town_slug') return 'spb';
+            return false;
+        });
+        $GLOBALS['post'] = (object) ['ID' => 84];
+
+        Redirect::handle();
+
+        self::assertTrue(true);
+    }
+
+    public function test_handle_redirects_when_post_is_page_unic_clone_without_prefix(): void
+    {
+        \Brain\Monkey\Functions\when('is_admin')->justReturn(false);
+        $_SERVER['REQUEST_URI'] = '/about/';
+        \Brain\Monkey\Functions\when('get_terms')->justReturn([11 => 'tyumen']);
+
+        $term = new \WP_Term();
+        $term->term_id = 11;
+        $term->slug = 'tyumen';
+        \Brain\Monkey\Functions\when('get_term_by')->justReturn($term);
+
+        \Brain\Monkey\Functions\when('get_field')->alias(function ($name) {
+            if ($name === 'main_town_slug') return 'spb';
+            if ($name === 'page_unic') return [
+                ['town' => 11, 'page_old' => 42, 'page_new' => 84],
+            ];
+            return false;
+        });
+        $GLOBALS['post'] = (object) ['ID' => 84];
+        \Brain\Monkey\Functions\when('get_permalink')->justReturn('https://site.com/about/');
+
+        \Brain\Monkey\Functions\expect('wp_safe_redirect')
+            ->once()
+            ->with('/tyumen/about/', 301)
+            ->andThrow(new \RuntimeException('redirect-called'));
+
+        try {
+            Redirect::handle();
+            self::fail('Expected redirect to be issued');
+        } catch (\RuntimeException $e) {
+            self::assertSame('redirect-called', $e->getMessage());
+        }
+    }
+}