Refactor admin bar functionality into own class

See #115.

assets/toolbar.css

@@ -38,6 +38,7 @@
 
 #wp-admin-bar-bc-cache-stats table td,
 #wp-admin-bar-bc-cache-stats table th {
+    border: 0;
     padding: 0.25em 0.5em;
 }
 

classes/BlueChip/Cache/AdminBar.php

@@ -0,0 +1,185 @@
+<?php
+
+declare(strict_types=1);
+
+namespace BlueChip\Cache;
+
+class AdminBar
+{
+    /**
+     * @var string Name of nonce used for AJAX-ified flush cache requests.
+     */
+    private const NONCE_FLUSH_CACHE_REQUEST = 'bc-cache/nonce:flush-cache-request';
+
+
+    public function __construct(
+        private string $plugin_filename,
+        private Core $cache,
+        private ?Feeder $cache_feeder,
+        private ?Crawler $cache_crawler,
+        private Viewer $cache_viewer,
+    ) {
+    }
+
+
+    public function init(): void
+    {
+        // Register method handling AJAX call from admin bar.
+        add_action('wp_ajax_bc_cache_flush_cache', $this->processFlushRequest(...), 10, 0);
+
+        if (is_admin_bar_showing()) {
+            // Add items to admin bar.
+            add_action('admin_bar_init', $this->enqueueToolbarAssets(...), 10, 0);
+            add_action('admin_bar_menu', $this->addToolbar(...), 110, 1);
+        }
+    }
+
+
+    /**
+     * Process AJAX flush request.
+     *
+     * @internal Is executed in context of AJAX request.
+     */
+    private function processFlushRequest(): void
+    {
+        // Check AJAX referer - die if invalid.
+        check_ajax_referer(self::NONCE_FLUSH_CACHE_REQUEST, false, true);
+
+        // TODO: in case of failure, indicate whether it's been access rights or I/O error.
+        if (Utils::canUserFlushCache() && $this->cache->flush()) {
+            wp_send_json_success();
+        } else {
+            wp_send_json_error();
+        }
+    }
+
+
+    /**
+     * @action https://developer.wordpress.org/reference/hooks/admin_bar_init/
+     */
+    private function enqueueToolbarAssets(): void
+    {
+        wp_enqueue_style(
+            'bc-cache-toolbar',
+            plugins_url('assets/toolbar.css', $this->plugin_filename),
+            [],
+            '20181201',
+            'all'
+        );
+
+        if (Utils::canUserFlushCache()) {
+            wp_enqueue_script(
+                'bc-cache-toolbar',
+                plugins_url('assets/toolbar.js', $this->plugin_filename),
+                ['jquery'],
+                '20190731',
+                true
+            );
+
+            wp_localize_script(
+                'bc-cache-toolbar',
+                'bc_cache_ajax_object',
+                [
+                    'ajaxurl' => admin_url('admin-ajax.php'), // necessary for the AJAX work properly on the frontend
+                    'nonce' => wp_create_nonce(self::NONCE_FLUSH_CACHE_REQUEST),
+                    'empty_cache_text' => __('Empty cache', 'bc-cache'),
+                    'warm_up_reset_text' => __('Warm-up status unavailable.', 'bc-cache'),
+                    'zero_age_text' => human_time_diff(\time()),
+                    'zero_size_text' => size_format(0),
+                ]
+            );
+        }
+    }
+
+
+    /**
+     * @action https://developer.wordpress.org/reference/hooks/admin_bar_menu/
+     *
+     * @param \WP_Admin_Bar $wp_admin_bar
+     */
+    private function addToolbar(\WP_Admin_Bar $wp_admin_bar): void
+    {
+        // If warm-up is enabled, add info about warm-up progress/status to the toolbar as well.
+        if ($this->cache_crawler && $this->cache_feeder) {
+            switch ($this->cache_crawler->getState()) {
+                case CrawlingState::FINISHED:
+                    $warm_up_class = 'bc-cache-warm-up-finished';
+                    $warm_up_status = __('Website is fully cached.', 'bc-cache');
+                    break;
+                case CrawlingState::RUNNING:
+                    $warm_up_class = 'bc-cache-warm-up-runs';
+                    $warm_up_status = \sprintf(
+                        __('Warm-up in progress (%d%%)', 'bc-cache'),
+                        $this->cache_feeder->getProgress(),
+                    );
+                    break;
+                case CrawlingState::SCHEDULED:
+                    $warm_up_class = 'bc-cache-warm-up-runs';
+                    $warm_up_status = \sprintf(
+                        __('Warm-up starts in %s.', 'bc-cache'),
+                        // Note: fallback value is not necessary here, but makes PHPStan happy.
+                        human_time_diff($this->cache_crawler->getNextScheduled() ?? 0),
+                    );
+                    break;
+                case CrawlingState::STALLED:
+                    $warm_up_class = 'bc-cache-warm-up-stalled';
+                    $warm_up_status = \sprintf(
+                        __('Warm-up stalled at %d%%.', 'bc-cache'),
+                        $this->cache_feeder->getProgress(),
+                    );
+                    break;
+            }
+        } else {
+            $warm_up_class = 'bc-cache-warm-up-off';
+            $warm_up_status = '';
+        }
+
+        // Add main BC Cache node.
+        $wp_admin_bar->add_node([
+            'id'    => 'bc-cache',
+            // 'parent' => 'top-secondary',
+            'title' => '<span class="ab-icon dashicons-html"></span><span class="ab-label">' . esc_html__('BC Cache', 'bc-cache') . '</span>',
+            'href'  => current_user_can(Viewer::REQUIRED_CAPABILITY) ? $this->cache_viewer->getUrl() : '',
+            'meta'  => [
+                'class' => $warm_up_class,
+            ]
+        ]);
+
+        // Add "stats" node.
+        $wp_admin_bar->add_node([
+            'id'        => 'bc-cache-stats',
+            'title'     => $this->getStatsNodeTable($this->cache->getSize(), $this->cache->getAge(), $warm_up_status),
+            'parent'    => 'bc-cache',
+        ]);
+
+        // Add "clear cache" node, but only if current user can flush cache.
+        if (Utils::canUserFlushCache()) {
+            $wp_admin_bar->add_node([
+                'id'        => 'bc-cache-clear-button',
+                'title'     => '<button id="bc-cache-clear"><span class="ab-icon dashicons-trash"><span class="bc-cache-spinner"></span></span><span class="ab-label">' . esc_html__('Clear cache', 'bc-cache') . '</span></button>',
+                'parent'    => 'bc-cache',
+            ]);
+        }
+    }
+
+
+    private function getStatsNodeTable(?int $cache_size, ?int $cache_age, string $warm_up_status): string
+    {
+        $rows = [];
+
+        // Heading
+        $rows[] = '<tr><th colspan="2">' . esc_html__('BC Cache Info', 'bc-cache') . '</th></tr>';
+
+        if ($warm_up_status) {
+            // Warm-up status (optional)
+            $rows[] = '<tr><td colspan="2" class="bc-cache-warm-up-status" id="bc-cache-toolbar-warm-up-status">' . esc_html($warm_up_status) . '</td></tr>';
+        }
+
+        // Cache size
+        $rows[] =  '<tr><td>' . esc_html__('Size:', 'bc-cache') . '</td><td id="bc-cache-toolbar-cache-size">' . esc_html(\is_int($cache_size) ? (string)size_format($cache_size) : __('unknown', 'bc-cache')) . '</td></tr>';
+        // Cache age
+        $rows[] = '<tr><td>' . esc_html__('Age:', 'bc-cache') . '</td><td id="bc-cache-toolbar-cache-age">' . esc_html(\is_int($cache_age) ? human_time_diff($cache_age) : __('unknown', 'bc-cache')) . '</td></tr>';
+
+        return '<table>' . \implode('', $rows) . '</table>';
+    }
+}