<?php
/**
 * Main plugin class.
 *
 * @package WP_FediStream
 */

namespace WP_FediStream;

use WP_FediStream\ActivityPub\Integration as ActivityPubIntegration;
use WP_FediStream\ActivityPub\RestApi as ActivityPubRestApi;
use WP_FediStream\Admin\ListColumns;
use WP_FediStream\Frontend\Ajax;
use WP_FediStream\Frontend\Shortcodes;
use WP_FediStream\Frontend\TemplateLoader;
use WP_FediStream\Frontend\Widgets;
use WP_FediStream\PostTypes\Artist;
use WP_FediStream\WooCommerce\Integration as WooCommerceIntegration;
use WP_FediStream\Prometheus\Integration as PrometheusIntegration;
use WP_FediStream\WooCommerce\DigitalDelivery;
use WP_FediStream\WooCommerce\StreamingAccess;
use WP_FediStream\PostTypes\Album;
use WP_FediStream\PostTypes\Track;
use WP_FediStream\PostTypes\Playlist;
use WP_FediStream\Taxonomies\Genre;
use WP_FediStream\Taxonomies\Mood;
use WP_FediStream\Taxonomies\License as LicenseTaxonomy;
use WP_FediStream\User\Library as UserLibrary;
use WP_FediStream\User\LibraryPage;
use WP_FediStream\User\Notifications;
use WP_FediStream\License\Manager as LicenseManager;

// Prevent direct file access.
if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

/**
 * Plugin singleton class.
 *
 * Initializes and manages all plugin components.
 */
final class Plugin {

    /**
     * Singleton instance.
     *
     * @var Plugin|null
     */
    private static ?Plugin $instance = null;

    /**
     * Current render depth to prevent infinite recursion.
     *
     * @var int
     */
    private static int $render_depth = 0;

    /**
     * Maximum allowed render depth.
     * Set to 2 to allow one level of nested includes but prevent deeper recursion.
     *
     * @var int
     */
    private const MAX_RENDER_DEPTH = 2;

    /**
     * Flag to track if we're currently rendering the main page template.
     * This is a hard lock that prevents ANY other rendering.
     *
     * @var bool
     */
    private static bool $rendering_main_template = false;

    /**
     * Post type instances.
     *
     * @var array
     */
    private array $post_types = array();

    /**
     * Taxonomy instances.
     *
     * @var array
     */
    private array $taxonomies = array();

    /**
     * Get singleton instance.
     *
     * @return Plugin
     */
    public static function get_instance(): Plugin {
        if ( null === self::$instance ) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    /**
     * Private constructor to enforce singleton pattern.
     */
    private function __construct() {
        $this->init_components();
        $this->init_hooks();
        $this->load_textdomain();
    }

    /**
     * Prevent cloning.
     *
     * @return void
     */
    private function __clone() {}

    /**
     * Prevent unserialization.
     *
     * @throws \Exception Always throws to prevent unserialization.
     * @return void
     */
    public function __wakeup(): void {
        throw new \Exception( 'Cannot unserialize singleton' );
    }

    /**
     * Initialize plugin components.
     *
     * @return void
     */
    private function init_components(): void {
        // Initialize post types.
        $this->post_types['artist']   = new Artist();
        $this->post_types['album']    = new Album();
        $this->post_types['track']    = new Track();
        $this->post_types['playlist'] = new Playlist();

        // Initialize taxonomies.
        $this->taxonomies['genre']   = new Genre();
        $this->taxonomies['mood']    = new Mood();
        $this->taxonomies['license'] = new LicenseTaxonomy();

        // Initialize admin components.
        if ( is_admin() ) {
            new ListColumns();
        }

        // Initialize frontend components (only if licensed).
        if ( ! is_admin() && LicenseManager::is_license_valid() ) {
            new TemplateLoader();
            new Shortcodes();
        } elseif ( ! is_admin() ) {
            // Register shortcodes that show license message.
            new Shortcodes( true ); // Unlicensed mode.
        }

        // Initialize widgets (always needed for admin widget management).
        new Widgets();

        // Initialize AJAX handlers.
        new Ajax();

        // Initialize ActivityPub integration (only if licensed and enabled).
        if ( get_option( 'wp_fedistream_enable_activitypub', 1 ) && LicenseManager::is_license_valid() ) {
            new ActivityPubIntegration();
            new ActivityPubRestApi();
        }

        // Initialize WooCommerce integration.
        if ( get_option( 'wp_fedistream_enable_woocommerce', 0 ) && $this->is_woocommerce_active() ) {
            new WooCommerceIntegration();
            new DigitalDelivery();
            new StreamingAccess();
        }

        // Initialize Prometheus integration.
        if ( get_option( 'wp_fedistream_enable_prometheus', 0 ) && $this->is_prometheus_active() ) {
            new PrometheusIntegration();
        }

        // Initialize user library and notifications.
        new UserLibrary();
        new LibraryPage();
        new Notifications();

        // Initialize license manager.
        LicenseManager::get_instance();
    }

    /**
     * Initialize WordPress hooks.
     *
     * @return void
     */
    private function init_hooks(): void {
        add_action( 'init', array( $this, 'maybe_install_defaults' ), 20 );
        add_action( 'admin_menu', array( $this, 'add_admin_menu' ) );
        add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_admin_assets' ) );
        add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_frontend_assets' ) );

        // Add settings link to plugins page.
        add_filter( 'plugin_action_links_' . WP_FEDISTREAM_BASENAME, array( $this, 'add_plugin_action_links' ) );
    }

    /**
     * Add action links to the plugins page.
     *
     * @param array $links Existing action links.
     * @return array Modified action links.
     */
    public function add_plugin_action_links( array $links ): array {
        $settings_link = sprintf(
            '<a href="%s">%s</a>',
            esc_url( admin_url( 'admin.php?page=fedistream-settings' ) ),
            esc_html__( 'Settings', 'wp-fedistream' )
        );

        $dashboard_link = sprintf(
            '<a href="%s">%s</a>',
            esc_url( admin_url( 'admin.php?page=fedistream' ) ),
            esc_html__( 'Dashboard', 'wp-fedistream' )
        );

        // Add our links at the beginning.
        array_unshift( $links, $dashboard_link, $settings_link );

        return $links;
    }

    /**
     * Maybe install default taxonomy terms.
     *
     * @return void
     */
    public function maybe_install_defaults(): void {
        Installer::install_defaults();
    }

    /**
     * Load plugin textdomain.
     *
     * @return void
     */
    private function load_textdomain(): void {
        load_plugin_textdomain(
            'wp-fedistream',
            false,
            dirname( WP_FEDISTREAM_BASENAME ) . '/languages'
        );
    }

    /**
     * Add admin menu.
     *
     * @return void
     */
    public function add_admin_menu(): void {
        // Main menu.
        add_menu_page(
            __( 'FediStream', 'wp-fedistream' ),
            __( 'FediStream', 'wp-fedistream' ),
            'edit_fedistream_tracks',
            'fedistream',
            array( $this, 'render_dashboard_page' ),
            'dashicons-format-audio',
            30
        );

        // Dashboard submenu.
        add_submenu_page(
            'fedistream',
            __( 'Dashboard', 'wp-fedistream' ),
            __( 'Dashboard', 'wp-fedistream' ),
            'edit_fedistream_tracks',
            'fedistream',
            array( $this, 'render_dashboard_page' )
        );

        // Artists submenu.
        add_submenu_page(
            'fedistream',
            __( 'Artists', 'wp-fedistream' ),
            __( 'Artists', 'wp-fedistream' ),
            'edit_fedistream_artists',
            'edit.php?post_type=fedistream_artist'
        );

        // Albums submenu.
        add_submenu_page(
            'fedistream',
            __( 'Albums', 'wp-fedistream' ),
            __( 'Albums', 'wp-fedistream' ),
            'edit_fedistream_albums',
            'edit.php?post_type=fedistream_album'
        );

        // Tracks submenu.
        add_submenu_page(
            'fedistream',
            __( 'Tracks', 'wp-fedistream' ),
            __( 'Tracks', 'wp-fedistream' ),
            'edit_fedistream_tracks',
            'edit.php?post_type=fedistream_track'
        );

        // Playlists submenu.
        add_submenu_page(
            'fedistream',
            __( 'Playlists', 'wp-fedistream' ),
            __( 'Playlists', 'wp-fedistream' ),
            'edit_fedistream_playlists',
            'edit.php?post_type=fedistream_playlist'
        );

        // Genres submenu.
        add_submenu_page(
            'fedistream',
            __( 'Genres', 'wp-fedistream' ),
            __( 'Genres', 'wp-fedistream' ),
            'manage_fedistream_genres',
            'edit-tags.php?taxonomy=fedistream_genre'
        );

        // Settings submenu.
        add_submenu_page(
            'fedistream',
            __( 'Settings', 'wp-fedistream' ),
            __( 'Settings', 'wp-fedistream' ),
            'manage_fedistream_settings',
            'fedistream-settings',
            array( $this, 'render_settings_page' )
        );
    }

    /**
     * Render dashboard page.
     *
     * @return void
     */
    public function render_dashboard_page(): void {
        // Get stats.
        $artist_count   = wp_count_posts( 'fedistream_artist' )->publish ?? 0;
        $album_count    = wp_count_posts( 'fedistream_album' )->publish ?? 0;
        $track_count    = wp_count_posts( 'fedistream_track' )->publish ?? 0;
        $playlist_count = wp_count_posts( 'fedistream_playlist' )->publish ?? 0;
        ?>
        <div class="wrap">
            <h1><?php esc_html_e( 'FediStream Dashboard', 'wp-fedistream' ); ?></h1>

            <div class="fedistream-dashboard">
                <div class="fedistream-stats" style="display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin: 20px 0;">
                    <div class="fedistream-stat-box" style="background: #fff; padding: 20px; border: 1px solid #ccd0d4; border-radius: 4px;">
                        <h3 style="margin: 0 0 10px;"><?php esc_html_e( 'Artists', 'wp-fedistream' ); ?></h3>
                        <p style="font-size: 2em; margin: 0; color: #2271b1;"><?php echo esc_html( $artist_count ); ?></p>
                        <a href="<?php echo esc_url( admin_url( 'edit.php?post_type=fedistream_artist' ) ); ?>"><?php esc_html_e( 'Manage Artists', 'wp-fedistream' ); ?></a>
                    </div>

                    <div class="fedistream-stat-box" style="background: #fff; padding: 20px; border: 1px solid #ccd0d4; border-radius: 4px;">
                        <h3 style="margin: 0 0 10px;"><?php esc_html_e( 'Albums', 'wp-fedistream' ); ?></h3>
                        <p style="font-size: 2em; margin: 0; color: #2271b1;"><?php echo esc_html( $album_count ); ?></p>
                        <a href="<?php echo esc_url( admin_url( 'edit.php?post_type=fedistream_album' ) ); ?>"><?php esc_html_e( 'Manage Albums', 'wp-fedistream' ); ?></a>
                    </div>

                    <div class="fedistream-stat-box" style="background: #fff; padding: 20px; border: 1px solid #ccd0d4; border-radius: 4px;">
                        <h3 style="margin: 0 0 10px;"><?php esc_html_e( 'Tracks', 'wp-fedistream' ); ?></h3>
                        <p style="font-size: 2em; margin: 0; color: #2271b1;"><?php echo esc_html( $track_count ); ?></p>
                        <a href="<?php echo esc_url( admin_url( 'edit.php?post_type=fedistream_track' ) ); ?>"><?php esc_html_e( 'Manage Tracks', 'wp-fedistream' ); ?></a>
                    </div>

                    <div class="fedistream-stat-box" style="background: #fff; padding: 20px; border: 1px solid #ccd0d4; border-radius: 4px;">
                        <h3 style="margin: 0 0 10px;"><?php esc_html_e( 'Playlists', 'wp-fedistream' ); ?></h3>
                        <p style="font-size: 2em; margin: 0; color: #2271b1;"><?php echo esc_html( $playlist_count ); ?></p>
                        <a href="<?php echo esc_url( admin_url( 'edit.php?post_type=fedistream_playlist' ) ); ?>"><?php esc_html_e( 'Manage Playlists', 'wp-fedistream' ); ?></a>
                    </div>
                </div>

                <div class="fedistream-quick-actions" style="background: #fff; padding: 20px; border: 1px solid #ccd0d4; border-radius: 4px; margin: 20px 0;">
                    <h2><?php esc_html_e( 'Quick Actions', 'wp-fedistream' ); ?></h2>
                    <p>
                        <a href="<?php echo esc_url( admin_url( 'post-new.php?post_type=fedistream_artist' ) ); ?>" class="button button-primary"><?php esc_html_e( 'Add Artist', 'wp-fedistream' ); ?></a>
                        <a href="<?php echo esc_url( admin_url( 'post-new.php?post_type=fedistream_album' ) ); ?>" class="button"><?php esc_html_e( 'Add Album', 'wp-fedistream' ); ?></a>
                        <a href="<?php echo esc_url( admin_url( 'post-new.php?post_type=fedistream_track' ) ); ?>" class="button"><?php esc_html_e( 'Add Track', 'wp-fedistream' ); ?></a>
                        <a href="<?php echo esc_url( admin_url( 'post-new.php?post_type=fedistream_playlist' ) ); ?>" class="button"><?php esc_html_e( 'Add Playlist', 'wp-fedistream' ); ?></a>
                    </p>
                </div>

                <div class="fedistream-info" style="background: #fff; padding: 20px; border: 1px solid #ccd0d4; border-radius: 4px;">
                    <h2><?php esc_html_e( 'Getting Started', 'wp-fedistream' ); ?></h2>
                    <ol>
                        <li><?php esc_html_e( 'Add your artists or bands.', 'wp-fedistream' ); ?></li>
                        <li><?php esc_html_e( 'Create albums and assign them to artists.', 'wp-fedistream' ); ?></li>
                        <li><?php esc_html_e( 'Upload tracks and add them to albums.', 'wp-fedistream' ); ?></li>
                        <li><?php esc_html_e( 'Create playlists to curate your music.', 'wp-fedistream' ); ?></li>
                        <li><?php esc_html_e( 'Share your music via ActivityPub to the Fediverse!', 'wp-fedistream' ); ?></li>
                    </ol>
                </div>
            </div>
        </div>
        <?php
    }

    /**
     * Render settings page.
     *
     * @return void
     */
    public function render_settings_page(): void {
        // Check user capabilities.
        if ( ! current_user_can( 'manage_fedistream_settings' ) ) {
            return;
        }

        // Get current tab.
        $current_tab = isset( $_GET['tab'] ) ? sanitize_key( $_GET['tab'] ) : 'license';

        // Handle form submissions.
        $this->handle_settings_save( $current_tab );

        // Get current settings.
        $enable_activitypub = get_option( 'wp_fedistream_enable_activitypub', 1 );
        $enable_woocommerce = get_option( 'wp_fedistream_enable_woocommerce', 0 );
        $enable_prometheus  = get_option( 'wp_fedistream_enable_prometheus', 0 );
        $max_upload_size    = get_option( 'wp_fedistream_max_upload_size', 50 );
        $default_license    = get_option( 'wp_fedistream_default_license', 'all-rights-reserved' );

        // License settings.
        $license_key        = LicenseManager::get_license_key();
        $license_server_url = LicenseManager::get_server_url();
        $license_status     = LicenseManager::get_cached_status();
        $license_data       = LicenseManager::get_cached_data();
        $last_check         = LicenseManager::get_last_check();

        $tabs = array(
            'license'      => __( 'License', 'wp-fedistream' ),
            'settings'     => __( 'Default Settings', 'wp-fedistream' ),
            'integrations' => __( 'Integrations', 'wp-fedistream' ),
        );
        ?>
        <div class="wrap">
            <h1><?php esc_html_e( 'FediStream Settings', 'wp-fedistream' ); ?></h1>

            <nav class="nav-tab-wrapper wp-clearfix">
                <?php foreach ( $tabs as $tab_key => $tab_label ) : ?>
                    <a href="<?php echo esc_url( admin_url( 'admin.php?page=fedistream-settings&tab=' . $tab_key ) ); ?>"
                       class="nav-tab <?php echo $current_tab === $tab_key ? 'nav-tab-active' : ''; ?>">
                        <?php echo esc_html( $tab_label ); ?>
                    </a>
                <?php endforeach; ?>
            </nav>

            <div class="fedistream-settings-content">
                <?php
                switch ( $current_tab ) {
                    case 'license':
                        $this->render_license_tab( $license_key, $license_server_url, $license_status, $license_data, $last_check );
                        break;
                    case 'settings':
                        $this->render_settings_tab( $max_upload_size, $default_license );
                        break;
                    case 'integrations':
                        $this->render_integrations_tab( $enable_activitypub, $enable_woocommerce, $enable_prometheus );
                        break;
                }
                ?>
            </div>
        </div>
        <?php
    }

    /**
     * Handle settings form submission.
     *
     * @param string $tab Current tab.
     * @return void
     */
    private function handle_settings_save( string $tab ): void {
        if ( ! isset( $_POST['fedistream_settings_nonce'] ) || ! wp_verify_nonce( sanitize_key( $_POST['fedistream_settings_nonce'] ), 'fedistream_save_settings' ) ) {
            return;
        }

        switch ( $tab ) {
            case 'license':
                LicenseManager::save_settings( array(
                    'license_key'   => isset( $_POST['license_key'] ) ? sanitize_text_field( wp_unslash( $_POST['license_key'] ) ) : '',
                    'server_url'    => isset( $_POST['license_server_url'] ) ? esc_url_raw( wp_unslash( $_POST['license_server_url'] ) ) : '',
                    'server_secret' => isset( $_POST['license_server_secret'] ) ? sanitize_text_field( wp_unslash( $_POST['license_server_secret'] ) ) : '',
                ) );
                echo '<div class="notice notice-success is-dismissible"><p>' . esc_html__( 'License settings saved.', 'wp-fedistream' ) . '</p></div>';
                break;

            case 'settings':
                update_option( 'wp_fedistream_max_upload_size', absint( $_POST['max_upload_size'] ?? 50 ) );
                update_option( 'wp_fedistream_default_license', sanitize_text_field( wp_unslash( $_POST['default_license'] ?? 'all-rights-reserved' ) ) );
                echo '<div class="notice notice-success is-dismissible"><p>' . esc_html__( 'Settings saved.', 'wp-fedistream' ) . '</p></div>';
                break;

            case 'integrations':
                update_option( 'wp_fedistream_enable_activitypub', isset( $_POST['enable_activitypub'] ) ? 1 : 0 );
                update_option( 'wp_fedistream_enable_woocommerce', isset( $_POST['enable_woocommerce'] ) ? 1 : 0 );
                update_option( 'wp_fedistream_enable_prometheus', isset( $_POST['enable_prometheus'] ) ? 1 : 0 );
                echo '<div class="notice notice-success is-dismissible"><p>' . esc_html__( 'Integration settings saved.', 'wp-fedistream' ) . '</p></div>';
                break;
        }
    }

    /**
     * Render the License tab.
     *
     * @param string $license_key   License key.
     * @param string $server_url    Server URL.
     * @param string $status        License status.
     * @param array  $license_data  License data.
     * @param int    $last_check    Last check timestamp.
     * @return void
     */
    private function render_license_tab( string $license_key, string $server_url, string $status, array $license_data, int $last_check ): void {
        $status_classes = array(
            'valid'        => 'notice-success',
            'invalid'      => 'notice-error',
            'expired'      => 'notice-warning',
            'revoked'      => 'notice-error',
            'inactive'     => 'notice-warning',
            'unchecked'    => 'notice-info',
            'unconfigured' => 'notice-info',
        );

        $status_messages = array(
            'valid'        => __( 'License is active and valid.', 'wp-fedistream' ),
            'invalid'      => __( 'License is invalid.', 'wp-fedistream' ),
            'expired'      => __( 'License has expired.', 'wp-fedistream' ),
            'revoked'      => __( 'License has been revoked.', 'wp-fedistream' ),
            'inactive'     => __( 'License is inactive. Please activate it.', 'wp-fedistream' ),
            'unchecked'    => __( 'License has not been validated yet.', 'wp-fedistream' ),
            'unconfigured' => __( 'License server is not configured.', 'wp-fedistream' ),
        );

        $status_icons = array(
            'valid'        => 'dashicons-yes-alt',
            'invalid'      => 'dashicons-dismiss',
            'expired'      => 'dashicons-warning',
            'revoked'      => 'dashicons-dismiss',
            'inactive'     => 'dashicons-marker',
            'unchecked'    => 'dashicons-info-outline',
            'unconfigured' => 'dashicons-admin-generic',
        );

        $status_class   = $status_classes[ $status ] ?? 'notice-info';
        $status_message = $status_messages[ $status ] ?? __( 'Unknown status.', 'wp-fedistream' );
        $status_icon    = $status_icons[ $status ] ?? 'dashicons-info-outline';
        ?>
        <div class="fedistream-license-status notice <?php echo esc_attr( $status_class ); ?>" style="padding: 12px; display: flex; align-items: center; gap: 10px;">
            <span class="dashicons <?php echo esc_attr( $status_icon ); ?>" style="font-size: 24px; width: 24px; height: 24px;"></span>
            <div>
                <strong><?php echo esc_html( $status_message ); ?></strong>
                <?php if ( 'valid' === $status && ! empty( $license_data['expires_at'] ) ) : ?>
                    <br>
                    <span class="description">
                        <?php
                        printf(
                            /* translators: %s: Expiration date */
                            esc_html__( 'Expires: %s', 'wp-fedistream' ),
                            esc_html( $license_data['expires_at'] )
                        );
                        ?>
                    </span>
                <?php elseif ( 'valid' === $status && empty( $license_data['expires_at'] ) ) : ?>
                    <br>
                    <span class="description"><?php esc_html_e( 'Lifetime license', 'wp-fedistream' ); ?></span>
                <?php endif; ?>
                <?php if ( $last_check > 0 ) : ?>
                    <br>
                    <span class="description">
                        <?php
                        printf(
                            /* translators: %s: Time ago */
                            esc_html__( 'Last checked: %s', 'wp-fedistream' ),
                            esc_html( human_time_diff( $last_check, time() ) . ' ' . __( 'ago', 'wp-fedistream' ) )
                        );
                        ?>
                    </span>
                <?php endif; ?>
            </div>
        </div>

        <form method="post" action="" id="fedistream-license-form">
            <?php wp_nonce_field( 'fedistream_save_settings', 'fedistream_settings_nonce' ); ?>

            <table class="form-table">
                <tr>
                    <th scope="row">
                        <label for="license_server_url"><?php esc_html_e( 'License Server URL', 'wp-fedistream' ); ?></label>
                    </th>
                    <td>
                        <input type="url" name="license_server_url" id="license_server_url"
                               value="<?php echo esc_attr( $server_url ); ?>"
                               class="regular-text" placeholder="https://example.com">
                        <p class="description"><?php esc_html_e( 'The URL of your license server.', 'wp-fedistream' ); ?></p>
                    </td>
                </tr>
                <tr>
                    <th scope="row">
                        <label for="license_key"><?php esc_html_e( 'License Key', 'wp-fedistream' ); ?></label>
                    </th>
                    <td>
                        <input type="text" name="license_key" id="license_key"
                               value="<?php echo esc_attr( $license_key ); ?>"
                               class="regular-text" placeholder="XXXX-XXXX-XXXX-XXXX">
                        <p class="description"><?php esc_html_e( 'Your license key from your purchase.', 'wp-fedistream' ); ?></p>
                    </td>
                </tr>
                <tr>
                    <th scope="row">
                        <label for="license_server_secret"><?php esc_html_e( 'Server Secret', 'wp-fedistream' ); ?></label>
                    </th>
                    <td>
                        <input type="password" name="license_server_secret" id="license_server_secret"
                               value="" class="regular-text" placeholder="<?php echo esc_attr( ! empty( LicenseManager::get_server_secret() ) ? '••••••••••••••••' : '' ); ?>">
                        <p class="description"><?php esc_html_e( '64-character verification secret from your license account. Leave empty to keep existing.', 'wp-fedistream' ); ?></p>
                    </td>
                </tr>
            </table>

            <p class="submit">
                <?php submit_button( __( 'Save License Settings', 'wp-fedistream' ), 'primary', 'submit', false ); ?>
                <button type="button" id="fedistream-validate-license" class="button button-secondary" style="margin-left: 10px;">
                    <span class="dashicons dashicons-yes" style="vertical-align: middle; margin-top: -2px;"></span>
                    <?php esc_html_e( 'Validate License', 'wp-fedistream' ); ?>
                </button>
                <button type="button" id="fedistream-activate-license" class="button button-secondary" style="margin-left: 10px;">
                    <span class="dashicons dashicons-admin-network" style="vertical-align: middle; margin-top: -2px;"></span>
                    <?php esc_html_e( 'Activate License', 'wp-fedistream' ); ?>
                </button>
                <span id="fedistream-license-spinner" class="spinner" style="float: none; margin-top: 4px;"></span>
            </p>
        </form>

        <div id="fedistream-license-message" style="display: none; margin-top: 10px;"></div>

        <script type="text/javascript">
            var fedistreamLicenseNonce = '<?php echo esc_js( wp_create_nonce( 'fedistream_license_action' ) ); ?>';
        </script>
        <?php
    }

    /**
     * Render the Default Settings tab.
     *
     * @param int    $max_upload_size Max upload size in MB.
     * @param string $default_license Default license.
     * @return void
     */
    private function render_settings_tab( int $max_upload_size, string $default_license ): void {
        ?>
        <form method="post" action="">
            <?php wp_nonce_field( 'fedistream_save_settings', 'fedistream_settings_nonce' ); ?>

            <table class="form-table">
                <tr>
                    <th scope="row">
                        <label for="max_upload_size"><?php esc_html_e( 'Max Upload Size', 'wp-fedistream' ); ?></label>
                    </th>
                    <td>
                        <input type="number" name="max_upload_size" id="max_upload_size" value="<?php echo esc_attr( $max_upload_size ); ?>" min="1" max="500" class="small-text"> MB
                        <p class="description"><?php esc_html_e( 'Maximum file size for audio uploads.', 'wp-fedistream' ); ?></p>
                    </td>
                </tr>
                <tr>
                    <th scope="row">
                        <label for="default_license"><?php esc_html_e( 'Default License', 'wp-fedistream' ); ?></label>
                    </th>
                    <td>
                        <select name="default_license" id="default_license">
                            <option value="all-rights-reserved" <?php selected( $default_license, 'all-rights-reserved' ); ?>><?php esc_html_e( 'All Rights Reserved', 'wp-fedistream' ); ?></option>
                            <option value="cc-by" <?php selected( $default_license, 'cc-by' ); ?>>CC BY</option>
                            <option value="cc-by-sa" <?php selected( $default_license, 'cc-by-sa' ); ?>>CC BY-SA</option>
                            <option value="cc-by-nc" <?php selected( $default_license, 'cc-by-nc' ); ?>>CC BY-NC</option>
                            <option value="cc-by-nc-sa" <?php selected( $default_license, 'cc-by-nc-sa' ); ?>>CC BY-NC-SA</option>
                            <option value="cc0" <?php selected( $default_license, 'cc0' ); ?>>CC0 (Public Domain)</option>
                        </select>
                        <p class="description"><?php esc_html_e( 'Default license for new uploads.', 'wp-fedistream' ); ?></p>
                    </td>
                </tr>
            </table>

            <?php submit_button(); ?>
        </form>
        <?php
    }

    /**
     * Render the Integrations tab.
     *
     * @param int $enable_activitypub Whether ActivityPub is enabled.
     * @param int $enable_woocommerce Whether WooCommerce integration is enabled.
     * @param int $enable_prometheus  Whether Prometheus metrics are enabled.
     * @return void
     */
    private function render_integrations_tab( int $enable_activitypub, int $enable_woocommerce, int $enable_prometheus ): void {
        ?>
        <form method="post" action="">
            <?php wp_nonce_field( 'fedistream_save_settings', 'fedistream_settings_nonce' ); ?>

            <table class="form-table">
                <tr>
                    <th scope="row"><?php esc_html_e( 'ActivityPub Integration', 'wp-fedistream' ); ?></th>
                    <td>
                        <label>
                            <input type="checkbox" name="enable_activitypub" value="1" <?php checked( $enable_activitypub, 1 ); ?>>
                            <?php esc_html_e( 'Enable ActivityPub features', 'wp-fedistream' ); ?>
                        </label>
                        <p class="description"><?php esc_html_e( 'Publish releases to the Fediverse and allow followers.', 'wp-fedistream' ); ?></p>
                        <?php if ( ! $this->is_activitypub_active() ) : ?>
                            <p class="description" style="color: #dba617;">
                                <span class="dashicons dashicons-warning" style="font-size: 16px; width: 16px; height: 16px; vertical-align: text-bottom;"></span>
                                <?php esc_html_e( 'The ActivityPub plugin is recommended for full Fediverse integration.', 'wp-fedistream' ); ?>
                            </p>
                        <?php endif; ?>
                    </td>
                </tr>
                <tr>
                    <th scope="row"><?php esc_html_e( 'WooCommerce Integration', 'wp-fedistream' ); ?></th>
                    <td>
                        <label>
                            <input type="checkbox" name="enable_woocommerce" value="1" <?php checked( $enable_woocommerce, 1 ); ?> <?php disabled( ! $this->is_woocommerce_active() ); ?>>
                            <?php esc_html_e( 'Enable WooCommerce features', 'wp-fedistream' ); ?>
                        </label>
                        <?php if ( ! $this->is_woocommerce_active() ) : ?>
                            <p class="description" style="color: #d63638;">
                                <span class="dashicons dashicons-dismiss" style="font-size: 16px; width: 16px; height: 16px; vertical-align: text-bottom;"></span>
                                <?php esc_html_e( 'WooCommerce is not installed or active.', 'wp-fedistream' ); ?>
                            </p>
                        <?php else : ?>
                            <p class="description"><?php esc_html_e( 'Sell albums and tracks through WooCommerce.', 'wp-fedistream' ); ?></p>
                        <?php endif; ?>
                    </td>
                </tr>
                <tr>
                    <th scope="row"><?php esc_html_e( 'Prometheus Metrics', 'wp-fedistream' ); ?></th>
                    <td>
                        <label>
                            <input type="checkbox" name="enable_prometheus" value="1" <?php checked( $enable_prometheus, 1 ); ?> <?php disabled( ! $this->is_prometheus_active() ); ?>>
                            <?php esc_html_e( 'Enable Prometheus metrics', 'wp-fedistream' ); ?>
                        </label>
                        <?php if ( ! $this->is_prometheus_active() ) : ?>
                            <p class="description" style="color: #d63638;">
                                <span class="dashicons dashicons-dismiss" style="font-size: 16px; width: 16px; height: 16px; vertical-align: text-bottom;"></span>
                                <?php esc_html_e( 'WP Prometheus plugin is not installed or active.', 'wp-fedistream' ); ?>
                            </p>
                        <?php else : ?>
                            <p class="description"><?php esc_html_e( 'Expose FediStream metrics for Prometheus monitoring.', 'wp-fedistream' ); ?></p>
                        <?php endif; ?>
                    </td>
                </tr>
            </table>

            <?php submit_button(); ?>
        </form>
        <?php
    }

    /**
     * Enqueue admin assets.
     *
     * @param string $hook_suffix The current admin page.
     * @return void
     */
    public function enqueue_admin_assets( string $hook_suffix ): void {
        // Only enqueue on FediStream pages.
        $screen = get_current_screen();
        if ( ! $screen ) {
            return;
        }

        $fedistream_screens = array(
            'toplevel_page_fedistream',
            'fedistream_page_fedistream-settings',
            'fedistream_artist',
            'fedistream_album',
            'fedistream_track',
            'fedistream_playlist',
            'edit-fedistream_artist',
            'edit-fedistream_album',
            'edit-fedistream_track',
            'edit-fedistream_playlist',
            'edit-fedistream_genre',
            'edit-fedistream_mood',
            'edit-fedistream_license',
        );

        if ( ! in_array( $screen->id, $fedistream_screens, true ) ) {
            return;
        }

        wp_enqueue_style(
            'wp-fedistream-admin',
            WP_FEDISTREAM_URL . 'assets/css/admin.css',
            array(),
            WP_FEDISTREAM_VERSION
        );

        wp_enqueue_script(
            'wp-fedistream-admin',
            WP_FEDISTREAM_URL . 'assets/js/admin.js',
            array( 'jquery', 'jquery-ui-sortable' ),
            WP_FEDISTREAM_VERSION,
            true
        );
    }

    /**
     * Enqueue frontend assets.
     *
     * @return void
     */
    public function enqueue_frontend_assets(): void {
        // Always enqueue as shortcodes/widgets can be used anywhere.
        // Assets are lightweight and properly cached.
        wp_enqueue_style(
            'wp-fedistream',
            WP_FEDISTREAM_URL . 'assets/css/frontend.css',
            array(),
            WP_FEDISTREAM_VERSION
        );

        wp_enqueue_script(
            'wp-fedistream',
            WP_FEDISTREAM_URL . 'assets/js/frontend.js',
            array(),
            WP_FEDISTREAM_VERSION,
            true
        );

        wp_localize_script(
            'wp-fedistream',
            'wpFediStream',
            array(
                'ajaxUrl' => admin_url( 'admin-ajax.php' ),
                'nonce'   => wp_create_nonce( 'wp-fedistream-nonce' ),
            )
        );
    }

    /**
     * Get the path to a template file.
     *
     * Checks theme for override first, then falls back to plugin template.
     *
     * @param string $template Template name (without extension).
     * @return string Full path to template file.
     */
    public function get_template_path( string $template ): string {
        // Check theme for override.
        $theme_template = locate_template( "fedistream/{$template}.php" );
        if ( $theme_template ) {
            return $theme_template;
        }

        // Use plugin template.
        return WP_FEDISTREAM_PATH . "templates/{$template}.php";
    }

    /**
     * Render a PHP template.
     *
     * @param string $template         Template name (without extension).
     * @param array  $context          Template context variables.
     * @param bool   $is_main_template Whether this is the main page template.
     * @return string Rendered template.
     */
    public function render( string $template, array $context = array(), bool $is_main_template = false ): string {
        // If we're already rendering the main template, block any other renders.
        if ( self::$rendering_main_template && ! $is_main_template ) {
            return '<!-- FediStream: blocked during main template render -->';
        }

        // Prevent infinite recursion in rendering.
        if ( self::$render_depth >= self::MAX_RENDER_DEPTH ) {
            return '<!-- FediStream: render depth exceeded -->';
        }

        // Set main template lock if this is the main template.
        $was_main = self::$rendering_main_template;
        if ( $is_main_template ) {
            self::$rendering_main_template = true;
        }

        ++self::$render_depth;

        try {
            $template_path = $this->get_template_path( $template );

            if ( ! file_exists( $template_path ) ) {
                throw new \Exception( "Template not found: {$template}" );
            }

            // Extract context variables for use in template.
            // phpcs:ignore WordPress.PHP.DontExtract.extract_extract
            extract( $context, EXTR_SKIP );

            // Start output buffering.
            ob_start();

            // Include the template.
            include $template_path;

            // Get the rendered content.
            $result = ob_get_clean();
        } finally {
            --self::$render_depth;
            if ( $is_main_template ) {
                self::$rendering_main_template = $was_main;
            }
        }

        return $result;
    }

    /**
     * Render a partial template (helper for use within templates).
     *
     * @param string $partial Partial template name (without extension).
     * @param array  $context Template context variables.
     * @return string Rendered partial.
     */
    public function render_partial( string $partial, array $context = array() ): string {
        return $this->render( $partial, $context, false );
    }

    /**
     * Get a post type instance.
     *
     * @param string $name Post type name.
     * @return object|null Post type instance or null.
     */
    public function get_post_type( string $name ): ?object {
        return $this->post_types[ $name ] ?? null;
    }

    /**
     * Get a taxonomy instance.
     *
     * @param string $name Taxonomy name.
     * @return object|null Taxonomy instance or null.
     */
    public function get_taxonomy( string $name ): ?object {
        return $this->taxonomies[ $name ] ?? null;
    }

    /**
     * Check if WooCommerce is active.
     *
     * @return bool
     */
    public function is_woocommerce_active(): bool {
        return class_exists( 'WooCommerce' );
    }

    /**
     * Check if ActivityPub plugin is active.
     *
     * @return bool
     */
    public function is_activitypub_active(): bool {
        return class_exists( 'Activitypub\Activitypub' );
    }

    /**
     * Check if WP Prometheus plugin is active.
     *
     * @return bool
     */
    public function is_prometheus_active(): bool {
        return defined( 'WP_PROMETHEUS_VERSION' ) || class_exists( 'WP_Prometheus\Plugin' );
    }
}