<?php
/**
 * Private folders for the admin lists of pages, posts, products and other post types (1.8.0). Nothing public.
 *
 * @package AffStackDevImageManager
 */

namespace AffStackDev\ImageManager;

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

/**
 * Folders for the admin lists of the post types chosen in Settings (a private taxonomy afsd_im_cf_<type> each): a
 * folder bar, a Folder column, the bulk actions Move to folder and Take out of its folder, and Manage folders. Nothing
 * public changes.
 */
final class Content_Folders {
	public const PREFIX      = 'afsd_im_cf_';
	public const QUERY       = 'afsd_im_cfolder';
	private const NOTICE     = 'afsd_im_cf_notice_';
	private const MOVE       = 'afsd_im_cf_move_';
	private const REMOVE     = 'afsd_im_cf_remove';
	public const MAX_FOLDERS = 500;
	public const MAX_ITEMS   = 999; // WordPress's own largest list page.
	/** WordPress's and WooCommerce's internal types, and Media (which has Image Manager's own folders). */
	private const EXCLUDED = array( 'attachment', 'revision', 'nav_menu_item', 'custom_css', 'customize_changeset', 'oembed_cache', 'user_request', 'wp_block', 'wp_template', 'wp_template_part', 'wp_global_styles', 'wp_navigation', 'wp_font_family', 'wp_font_face', 'shop_order', 'shop_order_refund', 'shop_order_placehold', 'scheduled-action' );
	/**
	 * Folders read in this request, per post type.
	 *
	 * @var array
	 */
	private static array $cache = array();

	/**
	 * The folder taxonomy of a post type.
	 *
	 * @param string $type The post type.
	 * @return string afsd_im_cf_ and the post type.
	 */
	public static function taxonomy( string $type ): string {
		return self::PREFIX . $type;
	}
	/** Post types that have an admin list and can take folders, as label by name. */
	public static function available(): array {
		$out = array();
		foreach ( get_post_types( array( 'show_ui' => true ), 'objects' ) as  $name => $object ) {
			if ( in_array( $name, self::EXCLUDED, true ) || strlen( self::taxonomy( $name ) ) > 32 || ! preg_match( '/^[a-z0-9_-]+$/D', $name ) ) {
				continue;
			}
			if ( function_exists( 'wc_get_order_types' ) && in_array( $name, wc_get_order_types(), true ) ) {
				continue;
			}
			$out[ $name ] = (string) $object->labels->name;
		}
		return $out;
	}
	/** Switched-on types that exist on this request. */
	public static function enabled(): array {
		$saved = Settings::get()['content_folders'];
		return array_values( array_filter( is_array( $saved ) ? $saved : array(), static fn( $type ) =>  is_string( $type ) && post_type_exists( $type ) && taxonomy_exists( self::taxonomy( $type ) ) ) );
	}
	/**
	 * The chosen post types kept to those that can take folders.
	 *
	 * @param mixed $types The post types asked for.
	 * @return array The post types.
	 */
	public static function clean_types( $types ): array {
		$available = self::available();
		$out       = array();
		foreach ( is_array( $types ) ? $types : array() as  $type ) {
			if ( is_string( $type ) && isset( $available[ $type ] ) ) {
				$out[] = $type;
			}
		}
		return array_values( array_unique( $out ) );
	}
	/**
	 * Register a private, hierarchical folder taxonomy for each chosen post type that exists and can take folders.
	 */
	public static function register(): void {
		$saved = Settings::get()['content_folders'];
		foreach ( is_array( $saved ) ? $saved : array() as  $type ) {
			if ( ! is_string( $type ) || ! post_type_exists( $type ) || in_array( $type, self::EXCLUDED, true ) || strlen( self::taxonomy( $type ) ) > 32 ) {
				continue;
			}
			$cap = get_post_type_object( $type )->cap;
			register_taxonomy(
				self::taxonomy( $type ),
				array( $type ),
				array(
					'public'             => false,
					'publicly_queryable' => false,
					'show_ui'            => false,
					'show_in_rest'       => false,
					'show_in_nav_menus'  => false,
					'show_tagcloud'      => false,
					'show_admin_column'  => false,
					'hierarchical'       => true,
					'query_var'          => false,
					'rewrite'            => false,
					'capabilities'       => array(
						'manage_terms' => $cap->edit_others_posts,
						'edit_terms'   => $cap->edit_others_posts,
						'delete_terms' => $cap->edit_others_posts,
						'assign_terms' => $cap->edit_posts,
					),
					'labels'             => array(
						'name'          => __( 'Folders', 'affstackdev-image-manager' ),
						'singular_name' => __( 'Folder', 'affstackdev-image-manager' ),
					),
				)
			);
		}
	}
	/**
	 * Whether the current user may manage a type's folders (they may edit others' items).
	 *
	 * @param string $type The post type.
	 * @return bool True when they may.
	 */
	public static function can_manage( string $type ): bool {
		$object = get_post_type_object( $type );
		return $object && current_user_can( $object->cap->edit_others_posts );
	}
	/**
	 * Whether the current user may move items of a type (they may edit such items).
	 *
	 * @param string $type The post type.
	 * @return bool True when they may.
	 */
	public static function can_use( string $type ): bool {
		$object = get_post_type_object( $type );
		return $object && current_user_can( $object->cap->edit_posts );
	}
	/**
	 * All folders of a type, ordered as a tree: each with id, name, parent, depth and path.
	 *
	 * @param string $type The post type.
	 * @return array The folders.
	 */
	public static function folders( string $type ): array {
		if ( isset( self::$cache[ $type ] ) ) {
			return self::$cache[ $type ];
		}
		$terms    = taxonomy_exists( self::taxonomy( $type ) ) ? get_terms(
			array(
				'taxonomy'   => self::taxonomy( $type ),
				'hide_empty' => false,
				'orderby'    => 'name',
				'order'      => 'ASC',
				'number'     => self::MAX_FOLDERS,
			)
		) : array();
		$children = array();
		$byid     = array();
		foreach ( is_array( $terms ) ? $terms : array() as  $t ) {
			$byid[ (int) $t->term_id ] = $t;
		}
		foreach ( $byid as  $id => $t ) {
			$parent                = isset( $byid[ (int) $t->parent ] ) ? (int) $t->parent : 0;
			$children[ $parent ][] = $id;
		}
		$out  = array();
		$walk = static function ( int $parent, int $depth, string $path ) use ( &$walk, &$out, $children, $byid ): void {
			foreach ( $children[ $parent ] ?? array() as  $id ) {
				$name       = (string) $byid[ $id ]->name;
				$full       = '' === $path ? $name : $path . ' › ' . $name;
				$out[ $id ] = array(
					'id'     => $id,
					'name'   => $name,
					'parent' => $parent,
					'depth'  => $depth,
					'path'   => $full,
				);
				if ( $depth < 20 ) {
					$walk( $id, $depth + 1, $full );
				}
			}
		};
		$walk( 0, 0, '' );
		return self::$cache[ $type ] = $out;
	}
	/**
	 * Forget the folders read in this request.
	 */
	public static function forget(): void {
		self::$cache = array();
	}
	/**
	 * Item counts per folder, all items and items in no folder. The trash and auto-drafts do not count.
	 *
	 * @param string $type The post type.
	 * @return array Folder => count, with all and none.
	 */
	public static function counts( string $type ): array {
		global $wpdb;
		$tax = self::taxonomy( $type );
        // phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Folder counts for the list screen in one grouped query; term counts of WordPress include the trash and cannot exclude it.
		$rows = $wpdb->get_results(
			$wpdb->prepare( "SELECT tt.term_id, COUNT(DISTINCT p.ID) AS n FROM %i tr INNER JOIN %i tt ON tt.term_taxonomy_id=tr.term_taxonomy_id INNER JOIN %i p ON p.ID=tr.object_id WHERE tt.taxonomy=%s AND p.post_type=%s AND p.post_status NOT IN ('trash','auto-draft','inherit') GROUP BY tt.term_id", $wpdb->term_relationships, $wpdb->term_taxonomy, $wpdb->posts, $tax, $type ),
			ARRAY_A
		);
		// phpcs:enable WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Same count basis as the folder counts above.
		$all = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM %i WHERE post_type=%s AND post_status NOT IN ('trash','auto-draft','inherit')", $wpdb->posts, $type ) );
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Same count basis as the folder counts above.
		$filed = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(DISTINCT p.ID) FROM %i tr INNER JOIN %i tt ON tt.term_taxonomy_id=tr.term_taxonomy_id INNER JOIN %i p ON p.ID=tr.object_id WHERE tt.taxonomy=%s AND p.post_type=%s AND p.post_status NOT IN ('trash','auto-draft','inherit')", $wpdb->term_relationships, $wpdb->term_taxonomy, $wpdb->posts, $tax, $type ) );
		$out   = array(
			'all'     => $all,
			'none'    => max( 0, $all - $filed ),
			'folders' => array(),
		);
		foreach ( is_array( $rows ) ? $rows : array() as  $r ) {
			$out['folders'][ (int) $r['term_id'] ] = (int) $r['n'];
		}
		return $out;
	}
	/**
	 * The folder an item is in.
	 *
	 * @param int    $post_id The item.
	 * @param string $type    Its post type.
	 * @return int The folder's ID, or 0.
	 */
	public static function folder_of( int $post_id, string $type ): int {
		$ids = wp_get_object_terms( $post_id, self::taxonomy( $type ), array( 'fields' => 'ids' ) );
		return is_array( $ids ) && $ids ? (int) $ids[0] : 0;
	}

	/* ---- Writers: owner lock, rights checked here, writes through Reviewed_Store. ---- */

	/**
	 * Make a folder, for someone who may manage the type's folders.
	 *
	 * @param string $type   The post type.
	 * @param string $name   Its name.
	 * @param int    $parent The parent folder (0 for the top).
	 * @return int The new folder's ID.
	 * @throws \RuntimeException With a content_folder_ reason code when it cannot be made.
	 */
	public static function create( string $type, string $name, int $parent = 0 ): int {
		$held = Reviewed_Store::enter( 8 );
		try {
			self::require_type( $type );
			if ( ! self::can_manage( $type ) ) {
				throw new \RuntimeException( 'content_folder_forbidden' );
			}
			$name = self::clean_name( $name );
			if ( count( self::folders( $type ) ) >= self::MAX_FOLDERS ) {
				throw new \RuntimeException( 'content_folder_limit' );
			}
			if ( $parent && ! isset( self::folders( $type )[ $parent ] ) ) {
				throw new \RuntimeException( 'content_folder_missing' );
			}
			foreach ( self::folders( $type ) as  $f ) {
				if ( $f['parent'] === $parent && 0 === strcasecmp( $f['name'], $name ) ) {
					throw new \RuntimeException( 'content_folder_exists' );
				}
			}
			$result = Reviewed_Store::wp_insert_term(
				$name,
				self::taxonomy( $type ),
				array(
					'parent' => $parent,
					'slug'   => 'f-' . strtolower( wp_generate_password( 10, false, false ) ),
				)
			);
			self::forget();
			if ( is_wp_error( $result ) ) {
				throw new \RuntimeException( 'content_folder_failed' );
			}
			return (int) $result['term_id'];
		} finally {
			Reviewed_Store::leave( $held );
		}
	}
	/**
	 * Rename a folder.
	 *
	 * @param string $type The post type.
	 * @param int    $id   The folder.
	 * @param string $name The new name.
	 * @throws \RuntimeException With a content_folder_ reason code when it cannot be renamed.
	 */
	public static function rename( string $type, int $id, string $name ): void {
		$held = Reviewed_Store::enter( 8 );
		try {
			self::require_folder( $type, $id );
			$name = self::clean_name( $name );
			$f    = self::folders( $type )[ $id ];
			foreach ( self::folders( $type ) as  $other ) {
				if ( $other['id'] !== $id && $other['parent'] === $f['parent'] && 0 === strcasecmp( $other['name'], $name ) ) {
					throw new \RuntimeException( 'content_folder_exists' );
				}
			}
			$result = Reviewed_Store::wp_update_term( $id, self::taxonomy( $type ), array( 'name' => $name ) );
			self::forget();
			if ( is_wp_error( $result ) ) {
				throw new \RuntimeException( 'content_folder_failed' );
			}
		} finally {
			Reviewed_Store::leave( $held );
		}
	}
	/**
	 * A folder moves under another one or to the top. Never into itself or one of its own sub-folders.
	 *
	 * @param string $type   The post type.
	 * @param int    $id     The folder.
	 * @param int    $parent The new parent (0 for the top).
	 * @throws \RuntimeException With a content_folder_ reason code when it cannot be moved there.
	 */
	public static function nest( string $type, int $id, int $parent ): void {
		$held = Reviewed_Store::enter( 8 );
		try {
			self::require_folder( $type, $id );
			$folders = self::folders( $type );
			if ( $parent && ! isset( $folders[ $parent ] ) ) {
				throw new \RuntimeException( 'content_folder_missing' );
			}
			for ( $p = $parent, $guard = 0; $p && $guard < 50; $p = $folders[ $p ]['parent'] ?? 0, $guard++ ) {
				if ( $p === $id ) {
					throw new \RuntimeException( 'content_folder_cycle' );
				}
			}
			foreach ( $folders as  $other ) {
				if ( $other['id'] !== $id && $other['parent'] === $parent && 0 === strcasecmp( $other['name'], $folders[ $id ]['name'] ) ) {
					throw new \RuntimeException( 'content_folder_exists' );
				}
			}
			$result = Reviewed_Store::wp_update_term( $id, self::taxonomy( $type ), array( 'parent' => $parent ) );
			self::forget();
			if ( is_wp_error( $result ) ) {
				throw new \RuntimeException( 'content_folder_failed' );
			}
		} finally {
			Reviewed_Store::leave( $held );
		}
	}
	/**
	 * WordPress moves the sub-folders up to this folder's parent; the items only lose this folder.
	 *
	 * @param string $type The post type.
	 * @param int    $id   The folder.
	 * @throws \RuntimeException With a content_folder_ reason code when it cannot be deleted.
	 */
	public static function delete( string $type, int $id ): void {
		$held = Reviewed_Store::enter( 8 );
		try {
			self::require_folder( $type, $id );
			$result = Reviewed_Store::wp_delete_term( $id, self::taxonomy( $type ) );
			self::forget();
			if ( true !== $result ) {
				throw new \RuntimeException( 'content_folder_failed' );
			}
		} finally {
			Reviewed_Store::leave( $held );
		}
	}
	/**
	 * Put items into one folder (0: take them out of their folder). Returns how many items now are where asked.
	 *
	 * @param string $type   The post type.
	 * @param array  $ids    The items.
	 * @param int    $folder The folder, or 0.
	 * @return int How many items are where asked.
	 * @throws \RuntimeException With a content_folder_ reason code when the items cannot be moved.
	 */
	public static function move( string $type, array $ids, int $folder ): int {
		$held = Reviewed_Store::enter( 8 );
		try {
			self::require_type( $type );
			if ( ! self::can_use( $type ) ) {
				throw new \RuntimeException( 'content_folder_forbidden' );
			}
			if ( $folder && ! isset( self::folders( $type )[ $folder ] ) ) {
				throw new \RuntimeException( 'content_folder_missing' );
			}
			$ids = array_slice( array_values( array_unique( array_filter( array_map( 'absint', $ids ) ) ) ), 0, self::MAX_ITEMS );
			if ( ! $ids ) {
				throw new \RuntimeException( 'content_folder_no_items' );
			}
			$done = 0;
			foreach ( $ids as  $id ) {
				if ( get_post_type( $id ) !== $type || ! current_user_can( 'edit_post', $id ) ) {
					continue;
				}
				$result = Reviewed_Store::wp_set_object_terms( $id, $folder ? array( $folder ) : array(), self::taxonomy( $type ), false );
				if ( ! is_wp_error( $result ) && self::folder_of( $id, $type ) === $folder ) {
					++$done;
				}
			}
			return $done;
		} finally {
			Reviewed_Store::leave( $held );
		}
	}
	/**
	 * Check a post type has folders switched on.
	 *
	 * @param string $type The post type.
	 * @throws \RuntimeException With content_folder_type_off when it has not.
	 */
	private static function require_type( string $type ): void {
		if ( ! in_array( $type, self::enabled(), true ) ) {
			throw new \RuntimeException( 'content_folder_type_off' );
		}
	}
	/**
	 * Check the current user may manage the type's folders and the folder exists.
	 *
	 * @param string $type The post type.
	 * @param int    $id   The folder.
	 * @throws \RuntimeException With a content_folder_ reason code when not.
	 */
	private static function require_folder( string $type, int $id ): void {
		self::require_type( $type );
		if ( ! self::can_manage( $type ) ) {
			throw new \RuntimeException( 'content_folder_forbidden' );
		}
		if ( ! isset( self::folders( $type )[ $id ] ) ) {
			throw new \RuntimeException( 'content_folder_missing' );
		}
	}
	/**
	 * A folder name as plain text, at most 120 characters.
	 *
	 * @param string $name The name asked for.
	 * @return string The name.
	 * @throws \RuntimeException With content_folder_name for an empty or too long name.
	 */
	private static function clean_name( string $name ): string {
		$name = trim( sanitize_text_field( $name ) );
		if ( '' === $name || strlen( $name ) > 120 ) {
			throw new \RuntimeException( 'content_folder_name' );
		}
		return $name;
	}
	/**
	 * The words for a folder reason code.
	 *
	 * @param string $code The reason code.
	 * @return string The translated words.
	 */
	public static function human_error( string $code ): string {
		$messages = array(
			'content_folder_forbidden'    => __( 'You cannot change these folders.', 'affstackdev-image-manager' ),
			'content_folder_type_unknown' => __( 'One of those list types does not exist on this site or cannot take folders.', 'affstackdev-image-manager' ),
			'content_folder_type_off'     => __( 'Folders are not switched on for this list. Switch them on in Image Manager: Settings, Folders for pages and posts.', 'affstackdev-image-manager' ),
			'content_folder_missing'      => __( 'That folder no longer exists. Reload the list and try again.', 'affstackdev-image-manager' ),
			'content_folder_exists'       => __( 'A folder with that name is already in the same place. Choose another name.', 'affstackdev-image-manager' ),
			'content_folder_name'         => __( 'Enter a folder name of at most 120 characters.', 'affstackdev-image-manager' ),
			'content_folder_limit'        => __( 'This list already has 500 folders, the most Image Manager keeps for one list.', 'affstackdev-image-manager' ),
			'content_folder_cycle'        => __( 'A folder cannot go into itself or into one of its own sub-folders.', 'affstackdev-image-manager' ),
			'content_folder_no_items'     => __( 'Check at least one item first.', 'affstackdev-image-manager' ),
			'content_folder_confirm'      => __( 'Tick the confirmation box, then delete again. Nothing was changed.', 'affstackdev-image-manager' ),
			'worker_busy'                 => __( 'Image Manager is finishing background work. Try again in a moment. Nothing was changed.', 'affstackdev-image-manager' ),
		);
		return $messages[ $code ] ?? __( 'The folders could not be changed. Reload the list and try again.', 'affstackdev-image-manager' );
	}

	/* ---- The list screen (edit.php). Reads only; every change goes through a form, a bulk action or the move request. ---- */

	/**
	 * The post type of the admin list being shown, when it has folders.
	 *
	 * @return string The post type, or an empty string.
	 */
	private static function screen_type(): string {
		global $typenow;
		$screen = function_exists( 'get_current_screen' ) ? get_current_screen() : null;
		if ( $screen && 'edit' === $screen->base && is_string( $screen->post_type ) && '' !== $screen->post_type ) {
			$type = $screen->post_type;
		} elseif ( is_string( $typenow ) && '' !== $typenow ) {
			$type = $typenow;
		} else {
			// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- the list screen's own post type, read only.
			$type = isset( $_GET['post_type'] ) && is_string( $_GET['post_type'] ) ? sanitize_key( wp_unslash( $_GET['post_type'] ) ) : 'post';
		} // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- the list screen's own post type, read only.
		return in_array( $type, self::enabled(), true ) && self::can_use( $type ) ? $type : '';
	}
	/**
	 * On a list with folders: filter its query by the chosen folder, and add the folder bar, the Folder column, the bulk
	 * actions and the filter that keeps the folder.
	 */
	public static function load(): void {
		$type = self::screen_type();
		if ( '' === $type ) {
			return;
		}
		add_action( 'pre_get_posts', array( self::class, 'filter_query' ) );
		add_action( 'all_admin_notices', array( self::class, 'bar' ) );
		add_action( 'restrict_manage_posts', array( self::class, 'keep_filter' ), 10, 2 );
		add_filter( 'bulk_actions-edit-' . $type, array( self::class, 'bulk_actions' ) );
		add_filter( 'handle_bulk_actions-edit-' . $type, array( self::class, 'bulk_handle' ), 10, 3 );
		add_filter( 'manage_' . $type . '_posts_columns', array( self::class, 'columns' ) );
		add_action( 'manage_' . $type . '_posts_custom_column', array( self::class, 'column' ), 10, 2 );
		add_filter( 'removable_query_args', static fn( $args ) =>  array_merge( (array) $args, array( 'afsd_im_cf_done' ) ) );
		add_action(
			'admin_enqueue_scripts',
			static function () use ( $type ): void {
				wp_enqueue_style( 'afsd-im-content-folders', plugins_url( 'assets/content-folders.css', FILE ), array(), VERSION );
				wp_enqueue_script( 'afsd-im-content-folders', plugins_url( 'assets/content-folders.js', FILE ), array(), VERSION, true );
				wp_localize_script(
					'afsd-im-content-folders',
					'afsdIMContentFolders',
					array(
						'ajax'   => admin_url( 'admin-ajax.php' ),
						'nonce'  => wp_create_nonce( 'afsd_im_cfolder_' . $type ),
						'type'   => $type,
						'drag'   => __( 'Drag onto a folder', 'affstackdev-image-manager' ),
						/* translators: %d: number of items being moved. */
						'moving' => __( 'Moving %d item(s)…', 'affstackdev-image-manager' ),
						'failed' => __( 'The items could not be moved. Reload the list and try again.', 'affstackdev-image-manager' ),
					)
				);
			}
		);
	}
	/**
	 * The folder chosen in the list's address.
	 *
	 * @return string none, a folder ID, or an empty string for all.
	 */
	private static function current(): string {
		$raw = isset( $_GET[ self::QUERY ] ) && is_string( $_GET[ self::QUERY ] ) ? sanitize_key( wp_unslash( $_GET[ self::QUERY ] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- read-only list filter.
		return 'none' === $raw || ctype_digit( $raw ) ? $raw : '';
	}
	/**
	 * Show only the chosen folder's items (or those in no folder) in the list's main query.
	 *
	 * @param mixed $query The query.
	 */
	public static function filter_query( $query ): void {
		if ( ! $query instanceof \WP_Query || ! $query->is_main_query() || ! is_admin() ) {
			return;
		}
		$type    = self::screen_type();
		$current = self::current();
		if ( '' === $type || '' === $current ) {
			return;
		}
		$clause   = 'none' === $current
			? array(
				'taxonomy' => self::taxonomy( $type ),
				'operator' => 'NOT EXISTS',
			)
			: array(
				'taxonomy'         => self::taxonomy( $type ),
				'field'            => 'term_id',
				'terms'            => array( (int) $current ),
				'include_children' => false,
			);
		$existing = $query->get( 'tax_query' );
        // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_tax_query -- The admin list of one post type filtered by the folder the user chose.
		$query->set( 'tax_query', array_merge( is_array( $existing ) ? $existing : array(), array( $clause ) ) );
	}
	/**
	 * The list's own filter form keeps the chosen folder.
	 *
	 * @param mixed $post_type The list's post type.
	 * @param mixed $which     top or bottom (the field is added once, at the top).
	 */
	public static function keep_filter( $post_type, $which = 'top' ): void {
		$current = self::current();
		if ( 'top' === $which && '' !== $current ) {
			echo '<input type="hidden" name="' . esc_attr( self::QUERY ) . '" value="' . esc_attr( $current ) . '">';
		}
	}
	/**
	 * The address of a list, with a folder chosen.
	 *
	 * @param string $type   The post type.
	 * @param string $folder The folder, none, or an empty string for all.
	 * @return string The address.
	 */
	private static function list_url( string $type, string $folder = '' ): string {
		$base = 'post' === $type ? admin_url( 'edit.php' ) : add_query_arg( 'post_type', $type, admin_url( 'edit.php' ) );
		return '' === $folder ? $base : add_query_arg( self::QUERY, $folder, $base );
	}
	/**
	 * Print the folder bar above the list: All, the folders with their counts, Not in a folder and Manage folders.
	 */
	public static function bar(): void {
		$type = self::screen_type();
		if ( '' === $type ) {
			return;
		}
		$folders = self::folders( $type );
		$counts  = self::counts( $type );
		$current = self::current();
		$label   = (string) get_post_type_object( $type )->labels->name;
		$notice  = get_transient( self::NOTICE . get_current_user_id() );
		if ( is_string( $notice ) ) {
			Reviewed_Store::delete_transient( self::NOTICE . get_current_user_id() );
		}
		echo '<nav class="afsd-im-cf" id="afsd-im-cf" aria-label="' . esc_attr__( 'Folders', 'affstackdev-image-manager' ) . '" data-type="' . esc_attr( $type ) . '"><strong class="afsd-im-cf-title">' . esc_html__( 'Folders', 'affstackdev-image-manager' ) . '</strong>';
		if ( is_string( $notice ) && '' !== $notice ) {
			echo '<p class="afsd-im-cf-notice" role="status">' . esc_html( $notice ) . '</p>';
		}
		echo '<ul class="afsd-im-cf-tree">';
		/* translators: 1: the list's name, such as Pages; 2: number of items. */
		self::link( $type, '', sprintf( __( 'All %1$s (%2$s)', 'affstackdev-image-manager' ), $label, number_format_i18n( $counts['all'] ) ), '' === $current, 0, 0 );
		/* translators: %s: number of items in no folder. */
		self::link( $type, 'none', sprintf( __( 'Not in a folder (%s)', 'affstackdev-image-manager' ), number_format_i18n( $counts['none'] ) ), 'none' === $current, 0, -1 );
		foreach ( $folders as  $f ) {
			self::link( $type, (string) $f['id'], $f['name'] . ' (' . number_format_i18n( $counts['folders'][ $f['id'] ] ?? 0 ) . ')', (string) $f['id'] === $current, $f['depth'], $f['id'] );
		}
		echo '</ul>';
		if ( self::can_manage( $type ) ) {
			self::manage_forms( $type, $folders );
		}
		echo '</nav>';
	}
	/**
	 * Print one link of the folder bar.
	 *
	 * @param string $type   The post type.
	 * @param string $folder The folder, none, or an empty string for all.
	 * @param string $text   The link's text.
	 * @param bool   $active Whether it is the folder shown.
	 * @param int    $depth  Its depth in the tree.
	 * @param int    $drop   Where items dropped on it go: a folder ID, -1 for no folder, 0 when nothing may be dropped on
	 *                       it.
	 */
	private static function link( string $type, string $folder, string $text, bool $active, int $depth, int $drop ): void {
		echo '<li class="afsd-im-cf-depth-' . esc_attr( (string) min( 6, $depth ) ) . '"' . ( 0 !== $drop ? ' data-folder="' . esc_attr( (string) max( 0, $drop ) ) . '"' : '' ) . '><a href="' . esc_url( self::list_url( $type, $folder ) ) . '"' . ( $active ? ' class="current" aria-current="page"' : '' ) . '>' . esc_html( $text ) . '</a></li>';
	}
	/**
	 * The options of a folder select, indented by depth.
	 *
	 * @param array  $folders  The folders.
	 * @param int    $selected The folder selected.
	 * @param string $none     The words for no folder ('' for no such option).
	 * @return string The options' HTML.
	 */
	private static function options( array $folders, int $selected = 0, string $none = '' ): string {
		$html = '' !== $none ? '<option value="0">' . esc_html( $none ) . '</option>' : '';
		foreach ( $folders as  $f ) {
			$html .= '<option value="' . esc_attr( (string) $f['id'] ) . '"' . selected( $selected, $f['id'], false ) . '>' . esc_html( str_repeat( '— ', $f['depth'] ) . $f['name'] ) . '</option>';
		}
		return $html;
	}
	/**
	 * Open one Manage folders form, with its nonce.
	 *
	 * @param string $type The post type.
	 * @param string $op   create, rename, nest or delete.
	 */
	private static function form( string $type, string $op ): void {
		echo '<form method="post" action="' . esc_url( admin_url( 'admin-post.php' ) )
			. '" class="afsd-im-cf-form"><input type="hidden" name="action" value="afsd_im_cfolder"><input type="hidden" name="op" value="' . esc_attr( $op )
			. '"><input type="hidden" name="post_type" value="' . esc_attr( $type ) . '"><input type="hidden" name="' . esc_attr( self::QUERY ) . '" value="'
			. esc_attr( self::current() ) . '">';
		wp_nonce_field( 'afsd_im_cfolder_' . $type );
	}
	/**
	 * Print the Manage folders forms: new, rename, move and delete.
	 *
	 * @param string $type    The post type.
	 * @param array  $folders Its folders.
	 */
	private static function manage_forms( string $type, array $folders ): void {
		echo '<details class="afsd-im-cf-manage"><summary>' . esc_html__( 'Manage folders', 'affstackdev-image-manager' ) . '</summary><div class="afsd-im-cf-forms">';
		self::form( $type, 'create' );
		echo '<label>' . esc_html__( 'New folder', 'affstackdev-image-manager' ) . ' <input type="text" name="folder_name" maxlength="120" required></label> <label>'
			. esc_html__( 'in', 'affstackdev-image-manager' ) . ' <select name="folder_parent">'
			. wp_kses( self::options( $folders, 0, __( 'the top level', 'affstackdev-image-manager' ) ), Admin_Layout::allowed_html() ) . '</select></label> <button type="submit" class="button">'
			. esc_html__( 'Create folder', 'affstackdev-image-manager' ) . '</button></form>';
		if ( $folders ) {
			self::form( $type, 'rename' );
			echo '<label>' . esc_html__( 'Rename', 'affstackdev-image-manager' ) . ' <select name="folder_id">' . wp_kses( self::options( $folders ), Admin_Layout::allowed_html() ) . '</select></label> <label>'
				. esc_html__( 'to', 'affstackdev-image-manager' )
				. ' <input type="text" name="folder_name" maxlength="120" required></label> <button type="submit" class="button">'
				. esc_html__( 'Rename', 'affstackdev-image-manager' ) . '</button></form>';
			self::form( $type, 'nest' );
			echo '<label>' . esc_html__( 'Move folder', 'affstackdev-image-manager' ) . ' <select name="folder_id">' . wp_kses( self::options( $folders ), Admin_Layout::allowed_html() )
				. '</select></label> <label>' . esc_html__( 'into', 'affstackdev-image-manager' ) . ' <select name="folder_parent">'
				. wp_kses( self::options( $folders, 0, __( 'the top level', 'affstackdev-image-manager' ) ), Admin_Layout::allowed_html() ) . '</select></label> <button type="submit" class="button">'
				. esc_html__( 'Move folder', 'affstackdev-image-manager' ) . '</button></form>';
			self::form( $type, 'delete' );
			echo '<label>' . esc_html__( 'Delete', 'affstackdev-image-manager' ) . ' <select name="folder_id">' . wp_kses( self::options( $folders ), Admin_Layout::allowed_html() )
				. '</select></label> <label class="afsd-im-cf-confirm"><input type="checkbox" name="folder_confirm" value="1"> '
				. esc_html__( 'Delete this folder. Its items stay as they are, outside any folder; its sub-folders move up one level.', 'affstackdev-image-manager' )
				. '</label> <button type="submit" class="button">' . esc_html__( 'Delete folder', 'affstackdev-image-manager' ) . '</button></form>';
		}
		echo '<p class="description">' . esc_html__( 'Folders only sort this list. Nothing changes on your website, and no address changes.', 'affstackdev-image-manager' ) . '</p></div></details>';
	}
	/**
	 * Add Move to folder (one choice per folder) and Take out of its folder to the list's bulk actions, for people who may
	 * move its items.
	 *
	 * @param mixed $actions The bulk actions.
	 * @return array The bulk actions.
	 */
	public static function bulk_actions( $actions ): array {
		$type    = self::screen_type();
		$actions = is_array( $actions ) ? $actions : array();
		if ( '' === $type ) {
			return $actions;
		}
		$move = array();
		foreach ( self::folders( $type ) as  $f ) {
			$move[ self::MOVE . $f['id'] ] = str_repeat( '— ', $f['depth'] ) . $f['name'];
		}
		if ( $move ) {
			$actions[ __( 'Move to folder', 'affstackdev-image-manager' ) ] = $move;
		}
		$actions[ self::REMOVE ] = __( 'Take out of its folder', 'affstackdev-image-manager' );
		return $actions;
	}
	/**
	 * WordPress has checked the list's nonce (bulk-posts) before this runs.
	 *
	 * @param mixed $redirect Where WordPress goes after the action.
	 * @param mixed $action   The bulk action.
	 * @param mixed $ids      The items chosen.
	 * @return mixed Where to go, with afsd_im_cf_done in its query.
	 */
	public static function bulk_handle( $redirect, $action, $ids ) {
		$type = self::screen_type();
		if ( '' === $type || ! is_string( $action ) || ( self::REMOVE !== $action && ! str_starts_with( $action, self::MOVE ) ) ) {
			return $redirect;
		}
		$folder = self::REMOVE === $action ? 0 : absint( substr( $action, strlen( self::MOVE ) ) );
		try {
			$n    = self::move( $type, is_array( $ids ) ? $ids : array(), $folder );
			$name = $folder ? ( self::folders( $type )[ $folder ]['path'] ?? '' ) : '';
			/* translators: 1: number of items; 2: folder name. */
			$message = $folder ? sprintf( _n( '%1$d item moved to %2$s.', '%1$d items moved to %2$s.', $n, 'affstackdev-image-manager' ), $n, $name ) : sprintf( _n( '%d item taken out of its folder.', '%d items taken out of their folders.', $n, 'affstackdev-image-manager' ), $n );
		} catch ( \RuntimeException $e ) {
			$message = self::human_error( $e->getMessage() );
		}
		Reviewed_Store::set_transient( self::NOTICE . get_current_user_id(), $message, 120 );
		return add_query_arg( 'afsd_im_cf_done', '1', $redirect );
	}
	/**
	 * Add the Folder column after the title.
	 *
	 * @param mixed $columns The list's columns.
	 * @return array The columns.
	 */
	public static function columns( $columns ): array {
		$columns = is_array( $columns ) ? $columns : array();
		$out     = array();
		foreach ( $columns as  $key => $label ) {
			$out[ $key ] = $label;
			if ( 'title' === $key || 'name' === $key ) {
				$out['afsd_im_cfolder'] = __( 'Folder', 'affstackdev-image-manager' );
			}
		}
		if ( ! isset( $out['afsd_im_cfolder'] ) ) {
			$out['afsd_im_cfolder'] = __( 'Folder', 'affstackdev-image-manager' );
		}
		return $out;
	}
	/**
	 * Print an item's folder in the Folder column.
	 *
	 * @param mixed $column  The column.
	 * @param mixed $post_id The item.
	 */
	public static function column( $column, $post_id ): void {
		if ( 'afsd_im_cfolder' !== $column ) {
			return;
		}
		$type = self::screen_type();
		if ( '' === $type ) {
			return;
		}
		$folder = self::folder_of( (int) $post_id, $type );
		$f      = self::folders( $type )[ $folder ] ?? null;
		echo $f ? '<a href="' . esc_url( self::list_url( $type, (string) $folder ) ) . '">' . esc_html( $f['path'] ) . '</a>' : '<span aria-hidden="true">—</span><span class="screen-reader-text">' . esc_html__( 'Not in a folder', 'affstackdev-image-manager' ) . '</span>';
	}
	/**
	 * The forms of Manage folders.
	 *
	 * @throws \RuntimeException Only inside this function, where it is caught; callers get no exception.
	 */
	public static function manage_request(): void {
		$type = isset( $_POST['post_type'] ) && is_string( $_POST['post_type'] ) ? sanitize_key( wp_unslash( $_POST['post_type'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Missing -- the nonce of this post type is checked on the next line.
		if ( '' === $type || ! check_admin_referer( 'afsd_im_cfolder_' . $type ) ) {
			wp_die( esc_html__( 'Your session expired. Reload the list and try again.', 'affstackdev-image-manager' ), '', array( 'response' => 403 ) );
		}
		if ( ! in_array( $type, self::enabled(), true ) || ! self::can_manage( $type ) ) {
			wp_die( esc_html( self::human_error( 'content_folder_forbidden' ) ), '', array( 'response' => 403 ) );
		}
		$data   = Plugin::fields( array( 'op', 'folder_id', 'folder_parent', 'folder_name', 'folder_confirm' ) );
		$op     = is_string( $data['op'] ?? null ) ? sanitize_key( $data['op'] ) : '';
		$id     = is_scalar( $data['folder_id'] ?? null ) ? absint( $data['folder_id'] ) : 0;
		$parent = is_scalar( $data['folder_parent'] ?? null ) ? absint( $data['folder_parent'] ) : 0;
		$name   = is_string( $data['folder_name'] ?? null ) ? $data['folder_name'] : '';
		try {
			if ( 'create' === $op ) {
				self::create( $type, $name, $parent );
				$message = __( 'Folder created.', 'affstackdev-image-manager' );
			} elseif ( 'rename' === $op ) {
				self::rename( $type, $id, $name );
				$message = __( 'Folder renamed.', 'affstackdev-image-manager' );
			} elseif ( 'nest' === $op ) {
				self::nest( $type, $id, $parent );
				$message = __( 'Folder moved.', 'affstackdev-image-manager' );
			} elseif ( 'delete' === $op ) {
				if ( empty( $data['folder_confirm'] ) ) {
					throw new \RuntimeException( 'content_folder_confirm' );
				}
				self::delete( $type, $id );
				$message = __( 'Folder deleted. Its items are now outside any folder; nothing else changed.', 'affstackdev-image-manager' );
			} else {
				$message = self::human_error( '' );
			}
		} catch ( \RuntimeException $e ) {
			$message = self::human_error( $e->getMessage() );
		}
		Reviewed_Store::set_transient( self::NOTICE . get_current_user_id(), $message, 120 );
		$current = is_string( $data[ self::QUERY ] ?? null ) ? sanitize_key( $data[ self::QUERY ] ) : '';
		if ( 'delete' === $op && (string) $id === $current ) {
			$current = '';
		}
		wp_safe_redirect( self::list_url( $type, 'none' === $current || ctype_digit( $current ) ? $current : '' ) );
		exit;
	}
	/** Rows dragged onto a folder (the bulk action does the same without a mouse). */
	public static function ajax_move(): void {
		$type = isset( $_POST['post_type'] ) && is_string( $_POST['post_type'] ) ? sanitize_key( wp_unslash( $_POST['post_type'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Missing -- the nonce of this post type is checked on the next line.
		if ( '' === $type || ! check_ajax_referer( 'afsd_im_cfolder_' . $type, '_wpnonce', false ) ) {
			wp_send_json_error( array( 'message' => __( 'Your session expired. Reload the list and try again.', 'affstackdev-image-manager' ) ), 403 );
		}
		$ids    = isset( $_POST['ids'] ) && is_string( $_POST['ids'] ) ? array_map( 'absint', explode( ',', sanitize_text_field( wp_unslash( $_POST['ids'] ) ) ) ) : array();
		$folder = isset( $_POST['folder'] ) && is_scalar( $_POST['folder'] ) ? absint( wp_unslash( $_POST['folder'] ) ) : 0;
		try {
			$n    = self::move( $type, $ids, $folder );
			$name = $folder ? ( self::folders( $type )[ $folder ]['path'] ?? '' ) : '';
			/* translators: 1: number of items; 2: folder name. */
			$message = $folder ? sprintf( _n( '%1$d item moved to %2$s.', '%1$d items moved to %2$s.', $n, 'affstackdev-image-manager' ), $n, $name ) : sprintf( _n( '%d item taken out of its folder.', '%d items taken out of their folders.', $n, 'affstackdev-image-manager' ), $n );
			Reviewed_Store::set_transient( self::NOTICE . get_current_user_id(), $message, 120 );
			wp_send_json_success(
				array(
					'moved'   => $n,
					'message' => $message,
				)
			);
		} catch ( \RuntimeException $e ) {
			$status = 'content_folder_forbidden' === $e->getMessage() ? 403 : ( 'worker_busy' === $e->getMessage() ? 409 : 400 );
			wp_send_json_error( array( 'message' => self::human_error( $e->getMessage() ) ), $status );
		}
	}
}