<?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\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;
use WP_FediStream\User\Library as UserLibrary;
use WP_FediStream\User\LibraryPage;
use WP_FediStream\User\Notifications;

// 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;

    /**
     * Twig environment instance.
     *
     * @var \Twig\Environment|null
     */
    private ?\Twig\Environment $twig = null;

    /**
     * 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_twig();
        $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 Twig template engine.
     *
     * @return void
     */
    private function init_twig(): void {
        $loader = new \Twig\Loader\FilesystemLoader( WP_FEDISTREAM_PATH . 'templates' );

        $this->twig = new \Twig\Environment(
            $loader,
            array(
                'cache'       => WP_FEDISTREAM_PATH . 'cache/twig',
                'auto_reload' => WP_DEBUG,
            )
        );

        // Add WordPress escaping functions.
        $this->twig->addFunction( new \Twig\TwigFunction( 'esc_html', 'esc_html' ) );
        $this->twig->addFunction( new \Twig\TwigFunction( 'esc_attr', 'esc_attr' ) );
        $this->twig->addFunction( new \Twig\TwigFunction( 'esc_url', 'esc_url' ) );
        $this->twig->addFunction( new \Twig\TwigFunction( 'esc_js', 'esc_js' ) );
        $this->twig->addFunction( new \Twig\TwigFunction( 'wp_nonce_field', 'wp_nonce_field', array( 'is_safe' => array( 'html' ) ) ) );
        $this->twig->addFunction( new \Twig\TwigFunction( '__', '__' ) );
        $this->twig->addFunction( new \Twig\TwigFunction( '_e', '_e' ) );
    }

    /**
     * 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 License();

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

        // Initialize frontend components.
        if ( ! is_admin() ) {
            new TemplateLoader();
            new Shortcodes();
        }

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

        // Initialize AJAX handlers.
        new Ajax();

        // Initialize ActivityPub integration.
        if ( get_option( 'wp_fedistream_enable_activitypub', 1 ) ) {
            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 user library and notifications.
        new UserLibrary();
        new LibraryPage();
        new Notifications();
    }

    /**
     * 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' ) );
    }

    /**
     * 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;
        }

        // Save settings.
        if ( isset( $_POST['fedistream_settings_nonce'] ) && wp_verify_nonce( sanitize_key( $_POST['fedistream_settings_nonce'] ), 'fedistream_save_settings' ) ) {
            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_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>';
        }

        // Get current settings.
        $enable_activitypub = get_option( 'wp_fedistream_enable_activitypub', 1 );
        $enable_woocommerce = get_option( 'wp_fedistream_enable_woocommerce', 0 );
        $max_upload_size    = get_option( 'wp_fedistream_max_upload_size', 50 );
        $default_license    = get_option( 'wp_fedistream_default_license', 'all-rights-reserved' );
        ?>
        <div class="wrap">
            <h1><?php esc_html_e( 'FediStream Settings', 'wp-fedistream' ); ?></h1>

            <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>
                        </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;"><?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">
                            <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>
        </div>
        <?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 Twig environment.
     *
     * @return \Twig\Environment
     */
    public function get_twig(): \Twig\Environment {
        return $this->twig;
    }

    /**
     * Render a Twig template.
     *
     * @param string $template Template name (without .twig extension).
     * @param array  $context  Template context variables.
     * @return string Rendered template.
     */
    public function render( string $template, array $context = array() ): string {
        return $this->twig->render( $template . '.twig', $context );
    }

    /**
     * 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' );
    }
}