<?php
/**
 * Admin Class.
 *
 * @package Activitypub
 */

namespace Activitypub\WP_Admin;

use Activitypub\Blocklist_Subscriptions;
use Activitypub\Collection\Actors;
use Activitypub\Collection\Extra_Fields;
use Activitypub\Comment;
use Activitypub\Model\Blog;
use Activitypub\Moderation;
use Activitypub\Scheduler\Actor;
use Activitypub\Tombstone;

use function Activitypub\count_followers;
use function Activitypub\get_content_visibility;
use function Activitypub\is_user_type_disabled;
use function Activitypub\site_supports_blocks;
use function Activitypub\user_can_activitypub;
use function Activitypub\was_comment_received;

/**
 * ActivityPub Admin Class.
 *
 * @author Matthias Pfefferle
 */
class Admin {
	/**
	 * Initialize the class, registering WordPress hooks,
	 */
	public static function init() {
		\add_action( 'load-comment.php', array( self::class, 'edit_comment' ) );
		\add_action( 'load-post.php', array( self::class, 'edit_post' ) );
		\add_action( 'load-edit.php', array( self::class, 'list_posts' ) );
		\add_filter( 'page_row_actions', array( self::class, 'row_actions' ), 10, 2 );
		\add_filter( 'post_row_actions', array( self::class, 'row_actions' ), 10, 2 );
		\add_action( 'personal_options_update', array( self::class, 'save_user_settings' ) );
		\add_action( 'admin_enqueue_scripts', array( self::class, 'enqueue_scripts' ) );
		\add_action( 'admin_notices', array( self::class, 'admin_notices' ) );

		\add_filter( 'comment_row_actions', array( self::class, 'comment_row_actions' ), 10, 2 );
		\add_filter( 'manage_edit-comments_columns', array( static::class, 'manage_comment_columns' ) );
		\add_action( 'manage_comments_custom_column', array( static::class, 'manage_comments_custom_column' ), 9, 2 );
		\add_filter( 'admin_comment_types_dropdown', array( static::class, 'comment_types_dropdown' ) );

		\add_filter( 'manage_posts_columns', array( static::class, 'manage_post_columns' ), 10, 2 );
		\add_action( 'manage_posts_custom_column', array( self::class, 'manage_posts_custom_column' ), 10, 2 );

		\add_filter( 'manage_users_columns', array( self::class, 'manage_users_columns' ) );
		\add_filter( 'manage_users_custom_column', array( self::class, 'manage_users_custom_column' ), 10, 3 );
		\add_filter( 'bulk_actions-users', array( self::class, 'user_bulk_options' ) );
		\add_filter( 'handle_bulk_actions-users', array( self::class, 'handle_bulk_request' ), 10, 3 );

		\add_action( 'admin_post_delete_actor_confirmed', array( self::class, 'handle_bulk_actor_delete_confirmation' ) );
		\add_action( 'admin_action_activitypub_confirm_removal', array( self::class, 'handle_bulk_actor_delete_page' ) );

		if ( user_can_activitypub( \get_current_user_id() ) ) {
			\add_action( 'show_user_profile', array( self::class, 'add_profile' ) );
		}

		\add_filter( 'dashboard_glance_items', array( self::class, 'dashboard_glance_items' ) );
		\add_filter( 'plugin_action_links_' . ACTIVITYPUB_PLUGIN_BASENAME, array( self::class, 'add_plugin_settings_link' ) );
		\add_action( 'in_plugin_update_message-' . ACTIVITYPUB_PLUGIN_BASENAME, array( self::class, 'plugin_update_message' ), 10, 2 );

		if ( site_supports_blocks() ) {
			\add_action( 'tool_box', array( self::class, 'tool_box' ) );
		}

		\add_action( 'admin_print_scripts-profile.php', array( self::class, 'enqueue_moderation_scripts' ) );
		\add_action( 'admin_print_scripts-settings_page_activitypub', array( self::class, 'enqueue_moderation_scripts' ) );
		\add_action( 'admin_print_footer_scripts-settings_page_activitypub', array( self::class, 'open_help_tab' ) );

		\add_action( 'wp_dashboard_setup', array( self::class, 'add_dashboard_widgets' ) );

		\add_action( 'wp_ajax_activitypub_moderation_settings', array( self::class, 'ajax_moderation_settings' ) );
		\add_action( 'wp_ajax_activitypub_blocklist_subscription', array( self::class, 'ajax_blocklist_subscription' ) );
	}

	/**
	 * Display admin menu notices about configuration problems or conflicts.
	 */
	public static function admin_notices() {
		$current_screen = get_current_screen();

		if ( ! $current_screen ) {
			return;
		}

		// Check for self-destruct completion notice.
		$self_destruct_complete = \get_option( 'activitypub_self_destruct_complete' );
		if ( $self_destruct_complete ) {
			// Show the notice only once, then remove it.
			\delete_option( 'activitypub_self_destruct_complete' );
			?>
			<div class="notice notice-success is-dismissible">
				<p>
					<strong><?php esc_html_e( 'ActivityPub Self-Destruct Complete!', 'activitypub' ); ?></strong>
				</p>
				<p>
					<?php esc_html_e( 'All Delete activities have been successfully sent to the Fediverse. Your blog is no longer discoverable via ActivityPub and all followers have been notified of the deletion.', 'activitypub' ); ?>
				</p>
			</div>
			<?php
		}

		if ( 'edit' === $current_screen->base && Extra_Fields::is_extra_fields_post_type( $current_screen->post_type ) ) {
			?>
			<div class="notice" style="margin: 0; background: none; border: none; box-shadow: none; padding: 15px 0 0 0; font-size: 14px;">
				<?php
					esc_html_e( 'These are extra fields that are used for your ActivityPub profile. You can use your homepage, social profiles, pronouns, age, anything you want.', 'activitypub' );
				?>
			</div>
			<?php
		}
	}

	/**
	 * Load user settings page.
	 */
	public static function followers_list_page() {
		// User has to be able to publish posts.
		if ( user_can_activitypub( \get_current_user_id() ) ) {
			\load_template( ACTIVITYPUB_PLUGIN_DIR . 'templates/followers-list.php' );
		}
	}

	/**
	 * Load user following list page.
	 */
	public static function following_list_page() {
		// User has to be able to publish posts.
		if ( user_can_activitypub( \get_current_user_id() ) ) {
			\load_template( ACTIVITYPUB_PLUGIN_DIR . 'templates/following-list.php' );
		}
	}

	/**
	 * Load blocked actors page.
	 */
	public static function blocked_actors_list_page() {
		// User has to be able to publish posts.
		if ( user_can_activitypub( \get_current_user_id() ) ) {
			\load_template( ACTIVITYPUB_PLUGIN_DIR . 'templates/blocked-actors-list.php' );
		}
	}

	/**
	 * Creates the followers and following list tables in ActivityPub settings.
	 */
	public static function add_settings_list_tables() {
		$tab = \sanitize_text_field( \wp_unslash( $_GET['tab'] ?? 'welcome' ) ); // phpcs:ignore WordPress.Security.NonceVerification

		switch ( $tab ) {
			case 'followers':
				self::add_followers_list_table();
				break;
			case 'following':
				self::add_following_list_table();
				break;
			case 'blocked-actors':
				self::add_blocked_actors_list_table();
				break;
		}
	}

	/**
	 * Creates the followers list table.
	 */
	public static function add_followers_list_table() {
		$GLOBALS['followers_list_table'] = new Table\Followers();
	}

	/**
	 * Creates the following list table.
	 */
	public static function add_following_list_table() {
		$GLOBALS['following_list_table'] = new Table\Following();
	}

	/**
	 * Creates the blocked actors list table.
	 */
	public static function add_blocked_actors_list_table() {
		$GLOBALS['blocked_actors_list_table'] = new Table\Blocked_Actors();
	}

	/**
	 * Render user settings.
	 */
	public static function add_profile() {
		wp_enqueue_media();
		wp_enqueue_script( 'activitypub-header-image' );

		wp_nonce_field( 'activitypub-user-settings', '_apnonce' );
		do_settings_sections( 'activitypub_user_settings' );
	}

	/**
	 * Save the user settings.
	 *
	 * Handles the saving of the ActivityPub settings.
	 *
	 * @param int $user_id The user ID.
	 */
	public static function save_user_settings( $user_id ) {
		if ( ! isset( $_REQUEST['_apnonce'] ) ) {
			return;
		}

		$nonce = sanitize_text_field( wp_unslash( $_REQUEST['_apnonce'] ) );
		if (
			! wp_verify_nonce( $nonce, 'activitypub-user-settings' ) ||
			! current_user_can( 'edit_user', $user_id )
		) {
			return;
		}

		// User options that should be processed with `sanitize_textarea_field()`.
		$textarea_field_user_options = array(
			'activitypub_also_known_as',
			'activitypub_description',
		);

		foreach ( $textarea_field_user_options as $option ) {
			if ( ! empty( $_POST[ $option ] ) ) {
				\update_user_option( $user_id, $option, sanitize_textarea_field( wp_unslash( $_POST[ $option ] ) ) );
			} else {
				\delete_user_option( $user_id, $option );
			}
		}

		// User options that should be processed with `sanitize_text_field()`.
		$text_field_user_options = array(
			'activitypub_header_image',
		);

		foreach ( $text_field_user_options as $option ) {
			if ( ! empty( $_POST[ $option ] ) ) {
				\update_user_option( $user_id, $option, sanitize_text_field( wp_unslash( $_POST[ $option ] ) ) );
			} else {
				\delete_user_option( $user_id, $option );
			}
		}

		// User options that have a default value and therefore can't be empty (Empty triggers the default value).
		$required_user_options = array(
			'activitypub_hide_social_graph',
			'activitypub_mailer_new_dm',
			'activitypub_mailer_new_follower',
			'activitypub_mailer_new_mention',
		);

		foreach ( $required_user_options as $option ) {
			\update_user_option( $user_id, $option, sanitize_text_field( wp_unslash( $_POST[ $option ] ?? 0 ) ) );
		}
	}

	/**
	 * Enqueue the admin scripts and styles.
	 *
	 * @param string $hook_suffix The current page.
	 */
	public static function enqueue_scripts( $hook_suffix ) {
		wp_register_script(
			'activitypub-header-image',
			plugins_url(
				'assets/js/activitypub-header-image.js',
				ACTIVITYPUB_PLUGIN_FILE
			),
			array( 'jquery' ),
			ACTIVITYPUB_PLUGIN_VERSION,
			false
		);

		// Register and enqueue command palette integration.
		if ( user_can_activitypub( \get_current_user_id() ) || \current_user_can( 'manage_options' ) ) {
			$asset_data = include ACTIVITYPUB_PLUGIN_DIR . 'build/command-palette/plugin.asset.php';
			wp_enqueue_script(
				'activitypub-command-palette',
				plugins_url( 'build/command-palette/plugin.js', ACTIVITYPUB_PLUGIN_FILE ),
				$asset_data['dependencies'],
				$asset_data['version'],
				true
			);

			wp_localize_script(
				'activitypub-command-palette',
				'activitypubCommandPalette',
				array(
					'followingEnabled' => '1' === \get_option( 'activitypub_following_ui', '0' ),
					'actorMode'        => \get_option( 'activitypub_actor_mode', ACTIVITYPUB_ACTOR_MODE ),
					'canManageOptions' => \current_user_can( 'manage_options' ),
				)
			);
		}

		if ( false !== strpos( $hook_suffix, 'activitypub' ) && 'dashboard_page_activitypub-social-web' !== $hook_suffix ) {
			wp_enqueue_style(
				'activitypub-admin-styles',
				plugins_url(
					'assets/css/activitypub-admin.css',
					ACTIVITYPUB_PLUGIN_FILE
				),
				array(),
				ACTIVITYPUB_PLUGIN_VERSION
			);
			wp_enqueue_script(
				'activitypub-admin-script',
				plugins_url(
					'assets/js/activitypub-admin.js',
					ACTIVITYPUB_PLUGIN_FILE
				),
				array( 'jquery', 'wp-util' ),
				ACTIVITYPUB_PLUGIN_VERSION,
				false
			);

			// Plugin cards in help tab.
			\wp_enqueue_script( 'plugin-install' );
			\add_thickbox();
			\wp_enqueue_script( 'updates' );
		}

		if ( 'index.php' === $hook_suffix ) {
			wp_enqueue_style(
				'activitypub-admin-styles',
				plugins_url(
					'assets/css/activitypub-admin.css',
					ACTIVITYPUB_PLUGIN_FILE
				),
				array(),
				ACTIVITYPUB_PLUGIN_VERSION
			);
		}

		if ( 'edit-comments.php' === $hook_suffix ) {
			\wp_add_inline_style(
				'wp-emoji-styles',
				'.column-author img.emoji { float: none; }'
			);
		}
	}

	/**
	 * Enqueue moderation admin scripts.
	 */
	public static function enqueue_moderation_scripts() {
		\wp_enqueue_script(
			'activitypub-moderation-admin',
			ACTIVITYPUB_PLUGIN_URL . 'assets/js/activitypub-moderation-admin.js',
			array( 'jquery', 'wp-util', 'wp-a11y', 'wp-i18n' ),
			ACTIVITYPUB_PLUGIN_VERSION,
			true
		);

		\wp_set_script_translations(
			'activitypub-moderation-admin',
			'activitypub',
			ACTIVITYPUB_PLUGIN_DIR . 'languages'
		);

		// Localize script with translations and nonces.
		\wp_localize_script(
			'activitypub-moderation-admin',
			'activitypubModerationL10n',
			array(
				'nonce' => \wp_create_nonce( 'activitypub_moderation_settings' ),
			)
		);
	}

	/**
	 * Hook into the edit_comment functionality.
	 *
	 * Disables the edit_comment capability for federated comments.
	 */
	public static function edit_comment() {
		// phpcs:ignore WordPress.Security.NonceVerification
		$comment_id = \absint( $_GET['c'] ?? 0 );
		if ( Comment::was_received( $comment_id ) ) {
			$path = 'edit-comments.php';

			switch ( \wp_get_comment_status( $comment_id ) ) { // phpcs:ignore WordPress.Security.NonceVerification
				case 'spam':
					$path = 'edit-comments.php?comment_status=spam';
					break;

				case 'trash':
					$path = 'edit-comments.php?comment_status=trash';
					break;

				case 'unapproved':
					$path = 'edit-comments.php?comment_status=moderated';
					break;
			}

			// Redirect to the appropriate comments page.
			\wp_safe_redirect( \admin_url( $path ) );
			exit;
		}
	}

	/**
	 * Hook into the edit_post functionality.
	 *
	 * Disables the edit_post capability for federated posts.
	 */
	public static function edit_post() {
		// Disable the edit_post capability for federated posts.
		\add_filter(
			'user_has_cap',
			static function ( $all_caps, $caps, $arg ) {
				if ( 'edit_post' !== $arg[0] ) {
					return $all_caps;
				}

				$post = get_post( $arg[2] );

				if ( ! Extra_Fields::is_extra_field_post_type( $post->post_type ) ) {
					return $all_caps;
				}

				if ( get_current_user_id() !== (int) $post->post_author ) {
					return false;
				}

				return $all_caps;
			},
			1,
			3
		);
	}

	/**
	 * Add ActivityPub specific actions/filters to the post list view.
	 */
	public static function list_posts() {
		// Remove all views for the extra fields.
		$screen_id = get_current_screen()->id;

		add_filter(
			"views_{$screen_id}",
			static function ( $views ) {
				if ( Extra_Fields::is_extra_fields_post_type( get_current_screen()->post_type ) ) {
					return array();
				}

				return $views;
			}
		);
	}

	/**
	 * Comment row actions.
	 *
	 * @param array           $actions The existing actions.
	 * @param int|\WP_Comment $comment The comment object or ID.
	 *
	 * @return array The modified actions.
	 */
	public static function comment_row_actions( $actions, $comment ) {
		if ( was_comment_received( $comment ) ) {
			unset( $actions['edit'], $actions['quickedit'] );
		}

		if ( in_array( get_comment_type( $comment ), Comment::get_comment_type_slugs(), true ) ) {
			unset( $actions['reply'] );
		}

		return $actions;
	}

	/**
	 * Add a column "activitypub".
	 *
	 * This column shows if the user has the capability to use ActivityPub.
	 *
	 * @param array $columns The columns.
	 *
	 * @return array The columns extended by the activitypub.
	 */
	public static function manage_users_columns( $columns ) {
		$columns['activitypub'] = __( 'ActivityPub', 'activitypub' );
		return $columns;
	}

	/**
	 * Add "comment-type" and "protocol" as column in WP-Admin.
	 *
	 * @param array $columns The list of column names.
	 *
	 * @return array The extended list of column names.
	 */
	public static function manage_comment_columns( $columns ) {
		$columns['comment_type']     = esc_attr__( 'Comment-Type', 'activitypub' );
		$columns['comment_protocol'] = esc_attr__( 'Protocol', 'activitypub' );

		return $columns;
	}

	/**
	 * Add "post_content" as column for Extra-Fields in WP-Admin.
	 *
	 * @param array  $columns   The list of column names.
	 * @param string $post_type The post type.
	 *
	 * @return array The extended list of column names.
	 */
	public static function manage_post_columns( $columns, $post_type ) {
		if ( Extra_Fields::is_extra_fields_post_type( $post_type ) ) {
			$after_key = 'title';
			$index     = array_search( $after_key, array_keys( $columns ), true );
			$columns   = array_slice( $columns, 0, $index + 1 ) + array( 'extra_field_content' => esc_attr__( 'Content', 'activitypub' ) ) + $columns;
		}

		return $columns;
	}

	/**
	 * Add "comment-type" and "protocol" as column in WP-Admin.
	 *
	 * @param array $column     The column to implement.
	 * @param int   $comment_id The comment id.
	 */
	public static function manage_comments_custom_column( $column, $comment_id ) {
		if ( 'comment_type' === $column && ! defined( 'WEBMENTION_PLUGIN_DIR' ) ) {
			echo esc_attr( ucfirst( get_comment_type( $comment_id ) ) );
		} elseif ( 'comment_protocol' === $column ) {
			$protocol = get_comment_meta( $comment_id, 'protocol', true );

			if ( $protocol ) {
				echo esc_attr( ucfirst( str_replace( 'activitypub', 'ActivityPub', $protocol ) ) );
			} else {
				esc_attr_e( 'Local', 'activitypub' );
			}
		}
	}

	/**
	 * Add the new ActivityPub comment types to the comment types dropdown.
	 *
	 * @param array $types The existing comment types.
	 *
	 * @return array The extended comment types.
	 */
	public static function comment_types_dropdown( $types ) {
		foreach ( Comment::get_comment_types() as $comment_type ) {
			$types[ $comment_type['type'] ] = esc_html( $comment_type['label'] );
		}

		return $types;
	}

	/**
	 * Return the results for the activitypub column.
	 *
	 * @param string $output      Custom column output. Default empty.
	 * @param string $column_name Column name.
	 * @param int    $user_id     ID of the currently-listed user.
	 *
	 * @return string The column contents.
	 */
	public static function manage_users_custom_column( $output, $column_name, $user_id ) {
		if ( 'activitypub' !== $column_name ) {
			return $output;
		}

		if ( \user_can( $user_id, 'activitypub' ) ) {
			return '<span aria-hidden="true">&#x2713;</span><span class="screen-reader-text">' . esc_html__( 'ActivityPub enabled for this author', 'activitypub' ) . '</span>';
		} else {
			return '<span aria-hidden="true">&#x2717;</span><span class="screen-reader-text">' . esc_html__( 'ActivityPub disabled for this author', 'activitypub' ) . '</span>';
		}
	}

	/**
	 * Add a column "extra_field_content" to the post list view.
	 *
	 * @param string $column_name The column name.
	 * @param int    $post_id     The post ID.
	 *
	 * @return void
	 */
	public static function manage_posts_custom_column( $column_name, $post_id ) {
		if ( 'extra_field_content' === $column_name ) {
			$post = get_post( $post_id );
			if ( Extra_Fields::is_extra_fields_post_type( $post->post_type ) ) {
				echo esc_attr( wp_strip_all_tags( $post->post_content ) );
			}
		}
	}

	/**
	 * Add options to the Bulk dropdown on the users page.
	 *
	 * @param array $actions The existing bulk options.
	 *
	 * @return array The extended bulk options.
	 */
	public static function user_bulk_options( $actions ) {
		$actions['add_activitypub_cap']    = __( 'Enable for ActivityPub', 'activitypub' );
		$actions['remove_activitypub_cap'] = __( 'Disable for ActivityPub', 'activitypub' );

		return $actions;
	}

	/**
	 * Handle bulk activitypub requests.
	 *
	 * * `add_activitypub_cap` - Add the activitypub capability to the selected users.
	 * * `remove_activitypub_cap` - Remove the activitypub capability from the selected users (redirects to confirmation page).
	 * * `delete_actor_confirmed` - Actually remove the capability after confirmation.
	 *
	 * @param string $send_back The URL to send the user back to.
	 * @param string $action    The requested action.
	 * @param array  $users     The selected users.
	 *
	 * @return string The URL to send the user back to.
	 */
	public static function handle_bulk_request( $send_back, $action, $users ) {
		switch ( $action ) {
			case 'add_activitypub_cap':
				foreach ( $users as $user_id ) {
					$user = new \WP_User( $user_id );
					$user->add_cap( 'activitypub' );

					// Remove user from tombstone registry if they were previously buried.
					$actor = Actors::get_by_id( $user_id );
					if ( ! \is_wp_error( $actor ) ) {
						Tombstone::remove( $actor->get_id(), $actor->get_url() );
					}
				}
				return $send_back;
			case 'remove_activitypub_cap':
				$removed_count = 0;

				// Remove capabilities immediately.
				foreach ( $users as $key => $user_id ) {
					$user = new \WP_User( $user_id );

					// Check if user has ActivityPub capability.
					if ( ! $user->has_cap( 'activitypub' ) ) {
						unset( $users[ $key ] );
						continue;
					}

					// Remove the capability.
					$user->remove_cap( 'activitypub' );

					// Force cache refresh for user capabilities.
					\wp_cache_delete( $user_id, 'users' );
					\wp_cache_delete( $user_id, 'user_meta' );

					++$removed_count;
				}

				// Build the query args with proper array handling for fediverse deletion confirmation.
				$query_args = array(
					'action'    => 'activitypub_confirm_removal',
					'send_back' => \rawurlencode( $send_back ),
				);

				// Add user IDs as separate parameters.
				foreach ( $users as $index => $user_id ) {
					$query_args[ sprintf( 'users[%d]', $index ) ] = absint( $user_id );
				}

				$confirmation_url = \add_query_arg( $query_args, \admin_url( 'users.php' ) );

				// Force redirect instead of just returning URL.
				\wp_safe_redirect( $confirmation_url );
				exit;
			case 'delete_actor_confirmed':
				// Use unified method with no fediverse deletion (keep).
				return self::process_capability_removal( $users, 'keep', $send_back );
			default:
				return $send_back;
		}
	}

	/**
	 * Handle the bulk capability removal page request directly.
	 */
	public static function handle_bulk_actor_delete_page() {

		// Check permissions.
		if ( ! \current_user_can( 'edit_users' ) ) {
			\wp_die( \esc_html__( 'You do not have sufficient permissions to access this page.', 'activitypub' ) );
		}

		// Get parameters.
		// phpcs:ignore WordPress.Security.NonceVerification, WordPress.Security.ValidatedSanitizedInput
		$users = \wp_unslash( $_GET['users'] ?? array() );
		// phpcs:ignore WordPress.Security.NonceVerification
		$send_back = \urldecode( \sanitize_text_field( \wp_unslash( $_GET['send_back'] ?? '' ) ) );

		// Sanitize user IDs.
		$users = \array_map( 'absint', (array) $users );
		$users = \array_filter( $users );

		// Validate send_back URL.
		if ( empty( $send_back ) ) {
			$send_back = \admin_url( 'users.php' );
		}

		// Load template and exit to prevent WordPress from trying to load other admin pages.
		\load_template(
			ACTIVITYPUB_PLUGIN_DIR . 'templates/bulk-actor-delete-confirmation.php',
			false,
			array(
				'users'     => $users,
				'send_back' => $send_back,
			)
		);
		exit;
	}


	/**
	 * Handle the bulk capability removal confirmation form submission.
	 */
	public static function handle_bulk_actor_delete_confirmation() {
		// Verify nonce.
		if ( ! \wp_verify_nonce( \sanitize_text_field( \wp_unslash( $_POST['_wpnonce'] ?? '' ) ), 'bulk-users' ) ) {
			\wp_die( \esc_html__( 'Security check failed.', 'activitypub' ) );
		}

		// Check permissions.
		if ( ! \current_user_can( 'edit_users' ) ) {
			\wp_die( \esc_html__( 'You do not have sufficient permissions to perform this action.', 'activitypub' ) );
		}

		// Get form data.
		// phpcs:ignore WordPress.Security.ValidatedSanitizedInput
		$selected_users = \wp_unslash( $_POST['selected_users'] ?? array() );
		// phpcs:ignore WordPress.Security.ValidatedSanitizedInput
		$remove_from_fediverse = \wp_unslash( $_POST['remove_from_fediverse'] ?? array() );
		$send_back             = \esc_url_raw( \wp_unslash( $_POST['send_back'] ?? '' ) );

		// Sanitize user IDs.
		$selected_users = \array_map( 'absint', (array) $selected_users );
		$selected_users = \array_filter( $selected_users );

		if ( empty( $selected_users ) ) {
			\wp_safe_redirect( $send_back );
			exit;
		}

		// Process capability removal using unified method.
		$result = self::process_capability_removal( $selected_users, $remove_from_fediverse, $send_back );

		// Redirect back.
		\wp_safe_redirect( $result );
		exit;
	}


	/**
	 * Process fediverse deletion for users (capabilities already removed).
	 *
	 * @param array        $users                  Array of user IDs.
	 * @param array|string $remove_from_fediverse  Array of user IDs to delete from fediverse, or 'delete'/'keep' for all users.
	 * @param string       $send_back              URL to redirect back to.
	 *
	 * @return string The URL to redirect to.
	 */
	public static function process_capability_removal( $users, $remove_from_fediverse, $send_back ) {
		// Normalize fediverse removal parameter.
		if ( is_string( $remove_from_fediverse ) ) {
			// Legacy format: 'delete' or 'keep' for all users.
			$delete_all      = ( 'delete' === $remove_from_fediverse );
			$users_to_delete = $delete_all ? $users : array();
		} else {
			// New format: array of specific user IDs to delete from fediverse.
			$remove_from_fediverse = \array_map( 'absint', (array) $remove_from_fediverse );
			$users_to_delete       = \array_filter( $remove_from_fediverse );
		}

		// Schedule delete activities for users who should be removed from fediverse.
		if ( ! empty( $users_to_delete ) ) {
			// Temporarily bypass capability checks for delete activity scheduling since capabilities were already removed.
			\add_filter( 'activitypub_user_can_activitypub', '__return_true' );

			\array_map(
				array(
					Actor::class,
					'schedule_user_delete',
				),
				$users_to_delete
			);

			\remove_filter( 'activitypub_user_can_activitypub', '__return_true' );
		}

		return $send_back;
	}

	/**
	 * Add ActivityPub infos to the dashboard glance items.
	 *
	 * @param array $items The existing glance items.
	 *
	 * @return array The extended glance items.
	 */
	public static function dashboard_glance_items( $items ) {
		\add_filter( 'number_format_i18n', '\Activitypub\custom_large_numbers', 10, 2 );

		if ( user_can_activitypub( \get_current_user_id() ) ) {
			$follower_count = sprintf(
				// translators: %s: number of followers.
				_n(
					'%s Follower',
					'%s Followers',
					count_followers( \get_current_user_id() ),
					'activitypub'
				),
				\number_format_i18n( count_followers( \get_current_user_id() ) )
			);
			$items['activitypub-followers-user'] = sprintf(
				'<a class="activitypub-followers" href="%1$s" title="%2$s">%3$s</a>',
				\esc_url( \admin_url( 'users.php?page=activitypub-followers-list' ) ),
				\esc_attr__( 'Your followers', 'activitypub' ),
				\esc_html( $follower_count )
			);
		}

		if ( ! is_user_type_disabled( 'blog' ) && current_user_can( 'manage_options' ) ) {
			$follower_count = sprintf(
				// translators: %s: number of followers.
				_n(
					'%s Follower (Blog)',
					'%s Followers (Blog)',
					count_followers( Actors::BLOG_USER_ID ),
					'activitypub'
				),
				\number_format_i18n( count_followers( Actors::BLOG_USER_ID ) )
			);
			$items['activitypub-followers-blog'] = sprintf(
				'<a class="activitypub-followers" href="%1$s" title="%2$s">%3$s</a>',
				\esc_url( \admin_url( 'options-general.php?page=activitypub&tab=followers' ) ),
				\esc_attr__( 'The Blog\'s followers', 'activitypub' ),
				\esc_html( $follower_count )
			);
		}

		\remove_filter( 'number_format_i18n', '\Activitypub\custom_large_numbers' );

		return $items;
	}

	/**
	 * Add a "Fediverse Preview ⁂" link to the row actions.
	 *
	 * @param array    $actions The existing actions.
	 * @param \WP_Post $post    The post object.
	 *
	 * @return array The modified actions.
	 */
	public static function row_actions( $actions, $post ) {
		// check if the post is enabled for ActivityPub.
		if (
			! \post_type_supports( \get_post_type( $post ), 'activitypub' ) ||
			! in_array( $post->post_status, array( 'pending', 'draft', 'future', 'publish' ), true ) ||
			! \current_user_can( 'edit_post', $post->ID ) ||
			ACTIVITYPUB_CONTENT_VISIBILITY_LOCAL === get_content_visibility( $post->ID ) ||
			( site_supports_blocks() && \use_block_editor_for_post_type( $post->post_type ) )
		) {
			return $actions;
		}

		$preview_url = add_query_arg( 'activitypub', 'true', \get_preview_post_link( $post ) );

		$actions['activitypub'] = sprintf(
			'<a href="%s" target="_blank">%s</a>',
			\esc_url( $preview_url ),
			\esc_html__( 'Fediverse Preview ⁂', 'activitypub' )
		);

		return $actions;
	}

	/**
	 * Add plugin settings link.
	 *
	 * @param array $actions The current actions.
	 */
	public static function add_plugin_settings_link( $actions ) {
		$actions[] = \sprintf(
			'<a href="%1s">%2s</a>',
			\menu_page_url( 'activitypub', false ),
			\__( 'Settings', 'activitypub' )
		);

		return $actions;
	}

	/**
	 * Display plugin upgrade notice to users.
	 *
	 * @param array  $data   The plugin data.
	 * @param object $update The plugin update data.
	 */
	public static function plugin_update_message( $data, $update ) {
		if ( ! isset( $update->upgrade_notice ) ) {
			return;
		}

		echo '<br>' . wp_strip_all_tags( $update->upgrade_notice ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
	}

	/**
	 * Adds meta box on wp-admin/tools.php.
	 */
	public static function tool_box() {
		\load_template( ACTIVITYPUB_PLUGIN_DIR . 'templates/toolbox.php' );
	}

	/**
	 * Open the help tab.
	 *
	 * This function is used to open the help tab,
	 * it is triggered by the hash in the URL.
	 */
	public static function open_help_tab() {
		// get all tabs registered for the ActivityPub settings page.
		$tabs = \get_current_screen()->get_help_tabs();
		$ids  = \array_values( \wp_list_pluck( $tabs, 'id' ) );
		$ids  = \array_map(
			static function ( $id ) {
				return '#tab-link-' . $id;
			},
			$ids
		);
		?>
		<script type="text/javascript">
		function activitypub_open_help_tab(event) {
			const allowed_ids = <?php echo \wp_json_encode( $ids ); ?>;

			if ( allowed_ids.includes( window.location.hash ) ) {
				const delay = ( event && event.type === 'hashchange' ) ? 0 : 200;

				setTimeout( function() {
					document.getElementById( 'contextual-help-link' ).click();
					document.querySelector( window.location.hash + ' > a[href^="#tab-panel-"]' ).click();
				}, delay );
			}
		}
		window.addEventListener( 'DOMContentLoaded', activitypub_open_help_tab );
		window.addEventListener( 'hashchange', activitypub_open_help_tab );
		</script>
		<?php
	}

	/**
	 * Add Dashboard widgets.
	 */
	public static function add_dashboard_widgets() {
		\wp_add_dashboard_widget( 'activitypub_blog', \__( 'ActivityPub Plugin News', 'activitypub' ), array( self::class, 'blog_dashboard_widget' ) );
		if ( user_can_activitypub( \get_current_user_id() ) && ! is_user_type_disabled( 'user' ) ) {
			\wp_add_dashboard_widget( 'activitypub_profile', \__( 'ActivityPub Author profile', 'activitypub' ), array( self::class, 'profile_dashboard_widget' ) );
		}
		if ( ! is_user_type_disabled( 'blog' ) ) {
			\wp_add_dashboard_widget( 'activitypub_blog_profile', \__( 'ActivityPub Blog profile', 'activitypub' ), array( self::class, 'blogprofile_dashboard_widget' ) );
		}
	}

	/**
	 * Add the `ActivityPub.blog` feed as a Dashboard widget.
	 */
	public static function blog_dashboard_widget() {
		echo '<div class="rss-widget">';
		\wp_widget_rss_output(
			array(
				'url'          => 'https://activitypub.blog/feed/',
				'items'        => 3,
				'show_summary' => 1,
				'show_author'  => 0,
				'show_date'    => 1,
			)
		);
		echo '</div>';
	}

	/**
	 * Add the ActivityPub Author profile as a Dashboard widget.
	 */
	public static function profile_dashboard_widget() {
		$user = Actors::get_by_id( \get_current_user_id() );
		?>
		<p>
			<?php \esc_html_e( 'People can follow you by using your author name:', 'activitypub' ); ?>
		</p>
		<p><label for="activitypub-user-identifier"><?php \esc_html_e( 'Username', 'activitypub' ); ?></label><input type="text" class="large-text code" id="activitypub-user-identifier" value="<?php echo \esc_attr( $user->get_webfinger() ); ?>" readonly /></p>
		<p><label for="activitypub-user-url"><?php \esc_html_e( 'Profile URL', 'activitypub' ); ?></label><input type="text" class="large-text code" id="activitypub-user-url" value="<?php echo \esc_attr( $user->get_url() ); ?>" readonly /></p>
		<p>
			<?php \esc_html_e( 'Authors who can not access this settings page will find their username on the "Edit Profile" page.', 'activitypub' ); ?>
			<a href="<?php echo \esc_url( \admin_url( '/profile.php#activitypub' ) ); ?>">
			<?php \esc_html_e( 'Customize username on "Edit Profile" page.', 'activitypub' ); ?>
			</a>
		</p>
		<?php
	}

	/**
	 * Add the ActivityPub Blog profile as a Dashboard widget.
	 */
	public static function blogprofile_dashboard_widget() {
		$user = new Blog();
		?>
		<p>
			<?php \esc_html_e( 'People can follow your blog by using:', 'activitypub' ); ?>
		</p>
		<p><label for="activitypub-user-identifier"><?php \esc_html_e( 'Username', 'activitypub' ); ?></label><input type="text" class="large-text code" id="activitypub-user-identifier" value="<?php echo \esc_attr( $user->get_webfinger() ); ?>" readonly /></p>
		<p><label for="activitypub-user-url"><?php \esc_html_e( 'Profile URL', 'activitypub' ); ?></label><input type="text" class="large-text code" id="activitypub-user-url" value="<?php echo \esc_attr( $user->get_url() ); ?>" readonly /></p>
		<p>
			<?php \esc_html_e( 'This blog profile will federate all posts written on your blog, regardless of the author who posted it.', 'activitypub' ); ?>
			<?php if ( current_user_can( 'manage_options' ) ) : ?>
			<a href="<?php echo \esc_url( \admin_url( '/options-general.php?page=activitypub&tab=blog-profile' ) ); ?>">
				<?php \esc_html_e( 'Customize the blog profile.', 'activitypub' ); ?>
			</a>
			<?php endif; ?>
		</p>
		<?php
	}

	/**
	 * AJAX handler for moderation settings (add/remove blocks).
	 */
	public static function ajax_moderation_settings() {
		$context   = \sanitize_text_field( \wp_unslash( $_POST['context'] ?? '' ) );
		$operation = \sanitize_text_field( \wp_unslash( $_POST['operation'] ?? '' ) );
		$type      = \sanitize_text_field( \wp_unslash( $_POST['type'] ?? '' ) );
		$value     = \sanitize_text_field( \wp_unslash( $_POST['value'] ?? '' ) );

		// Validate required parameters.
		if ( ! in_array( $context, array( 'user', 'site' ), true ) || ! in_array( $operation, array( 'add', 'remove' ), true ) ) {
			\wp_send_json_error( array( 'message' => \__( 'Invalid context or action.', 'activitypub' ) ) );
		}

		if ( empty( $type ) || empty( $value ) || ! in_array( $type, array( 'domain', 'keyword' ), true ) ) {
			\wp_send_json_error( array( 'message' => \__( 'Invalid parameters.', 'activitypub' ) ) );
		}

		// Verify nonce for all operations.
		if ( ! \wp_verify_nonce( \sanitize_text_field( \wp_unslash( $_POST['_wpnonce'] ?? '' ) ), 'activitypub_moderation_settings' ) ) {
			\wp_send_json_error( array( 'message' => \__( 'Invalid nonce.', 'activitypub' ) ) );
		}

		if ( ! \current_user_can( 'manage_options' ) ) {
			\wp_send_json_error( array( 'message' => \__( 'You do not have permission to perform this action.', 'activitypub' ) ) );
		}

		if ( 'user' === $context ) {
			$user_id = (int) ( \sanitize_text_field( \wp_unslash( $_POST['user_id'] ?? 0 ) ) );

			// Check permissions.
			if ( \get_current_user_id() !== $user_id ) {
				\wp_send_json_error( array( 'message' => \__( 'You do not have permission to perform this action.', 'activitypub' ) ) );
			}

			if ( ! $user_id ) {
				\wp_send_json_error( array( 'message' => \__( 'Invalid user ID.', 'activitypub' ) ) );
			}

			if ( 'add' === $operation ) {
				$success       = Moderation::add_user_block( $user_id, $type, $value );
				$error_message = \__( 'Failed to add block.', 'activitypub' );
			} else {
				$success       = Moderation::remove_user_block( $user_id, $type, $value );
				$error_message = \__( 'Failed to remove block.', 'activitypub' );
			}
		} elseif ( 'add' === $operation ) {
				$success       = Moderation::add_site_block( $type, $value );
				$error_message = \__( 'Failed to add block.', 'activitypub' );
		} else {
			$success       = Moderation::remove_site_block( $type, $value );
			$error_message = \__( 'Failed to remove block.', 'activitypub' );
		}

		if ( $success ) {
			\wp_send_json_success();
		} else {
			\wp_send_json_error( array( 'message' => $error_message ) );
		}
	}

	/**
	 * AJAX handler for blocklist subscriptions (add/remove).
	 */
	public static function ajax_blocklist_subscription() {
		$operation = \sanitize_text_field( \wp_unslash( $_POST['operation'] ?? '' ) );
		$url       = \sanitize_url( \wp_unslash( $_POST['url'] ?? '' ) );

		// Validate required parameters.
		if ( ! \in_array( $operation, array( 'add', 'remove' ), true ) ) {
			\wp_send_json_error( array( 'message' => \__( 'Invalid operation.', 'activitypub' ) ) );
		}

		if ( empty( $url ) ) {
			\wp_send_json_error( array( 'message' => \__( 'Invalid URL.', 'activitypub' ) ) );
		}

		// Verify nonce.
		if ( ! \wp_verify_nonce( \sanitize_text_field( \wp_unslash( $_POST['_wpnonce'] ?? '' ) ), 'activitypub_moderation_settings' ) ) {
			\wp_send_json_error( array( 'message' => \__( 'Invalid nonce.', 'activitypub' ) ) );
		}

		if ( ! \current_user_can( 'manage_options' ) ) {
			\wp_send_json_error( array( 'message' => \__( 'You do not have permission to perform this action.', 'activitypub' ) ) );
		}

		if ( 'add' === $operation ) {
			// First add the subscription (validates URL format).
			if ( ! Blocklist_Subscriptions::add( $url ) ) {
				\wp_send_json_error( array( 'message' => \__( 'Invalid URL.', 'activitypub' ) ) );
			}

			// Then sync to validate it works and import domains.
			$result = Blocklist_Subscriptions::sync( $url );
			if ( false === $result ) {
				// Remove the subscription since sync failed.
				Blocklist_Subscriptions::remove( $url );
				\wp_send_json_error( array( 'message' => \__( 'Failed to fetch blocklist. The URL may be unreachable or not contain valid domains.', 'activitypub' ) ) );
			}

			\wp_send_json_success();
		} elseif ( Blocklist_Subscriptions::remove( $url ) ) {
			\wp_send_json_success();
		} else {
			\wp_send_json_error( array( 'message' => \__( 'Failed to remove subscription.', 'activitypub' ) ) );
		}
	}
}
