<?php
/**
 * Gutenberg block editor support for Admin Notes
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

class BW_Admin_Note_Gutenberg {

    private static $instance = null;

    /**
     * Track which post types we've registered meta for
     */
    private $registered_meta_types = array();

    public static function get_instance() {
        if ( null === self::$instance ) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    private function __construct() {
        add_action( 'enqueue_block_editor_assets', array( $this, 'enqueue_editor_assets' ) );

        // Register meta for existing post types
        $this->register_meta();

        // Also register meta for post types registered after us
        add_action( 'registered_post_type', array( $this, 'register_meta_for_post_type' ), 10, 2 );
    }

    /**
     * Register post meta for REST API access
     */
    public function register_meta() {
        // Get all public post types that support the editor
        $post_types = get_post_types( array( 'public' => true, 'show_in_rest' => true ), 'names' );

        // Remove attachment
        unset( $post_types['attachment'] );

        foreach ( $post_types as $post_type ) {
            $this->register_meta_for_single_type( $post_type );
        }
    }

    /**
     * Register meta for a single post type (called when post type is registered)
     */
    public function register_meta_for_post_type( $post_type, $post_type_object ) {
        // Only register for public post types with REST support
        if ( ! $post_type_object->public || ! $post_type_object->show_in_rest ) {
            return;
        }

        // Skip attachment
        if ( 'attachment' === $post_type ) {
            return;
        }

        $this->register_meta_for_single_type( $post_type );
    }

    /**
     * Register meta fields for a single post type
     */
    private function register_meta_for_single_type( $post_type ) {
        // Skip if already registered
        if ( in_array( $post_type, $this->registered_meta_types, true ) ) {
            return;
        }

        $this->registered_meta_types[] = $post_type;

        register_post_meta( $post_type, '_bw_admin_note', array(
            'show_in_rest'      => true,
            'single'            => true,
            'type'              => 'string',
            'default'           => '',
            'sanitize_callback' => 'wp_kses_post', // Allow basic HTML
            'auth_callback'     => function() {
                return current_user_can( 'edit_posts' );
            },
        ) );
    }

    /**
     * Enqueue block editor assets
     */
    public function enqueue_editor_assets() {
        global $post;

        // Check if current post type is enabled
        if ( ! isset( $post ) ) {
            return;
        }

        $plugin = BW_Admin_Note::get_instance();
        if ( ! $plugin->is_post_type_enabled( $post->post_type ) ) {
            return;
        }

        // Enqueue the Gutenberg panel script
        wp_enqueue_script(
            'bw-admin-note-gutenberg',
            BW_ADMIN_NOTE_PLUGIN_URL . 'assets/js/gutenberg-panel.js',
            array(
                'wp-plugins',
                'wp-edit-post',
                'wp-element',
                'wp-components',
                'wp-data',
                'wp-i18n',
                'wp-compose',
            ),
            BW_ADMIN_NOTE_VERSION,
            true
        );

        // Pass data to script
        wp_localize_script( 'bw-admin-note-gutenberg', 'bwAdminNoteData', array(
            'metaKey' => '_bw_admin_note',
            'labels'  => array(
                'panelTitle'  => __( 'Admin Note', 'bw-admin-note' ),
                'placeholder' => __( 'Add a note for editors (only visible in admin)...', 'bw-admin-note' ),
                'helpText'    => __( 'This note is only visible to logged-in users in the editor. It will not appear on the frontend.', 'bw-admin-note' ),
            ),
        ) );
    }
}