<?php
/**
 * Read-only WordPress session visibility.
 *
 * @package AdminWatch
 */

defined( 'ABSPATH' ) || exit;

/**
 * Counts valid core WordPress sessions without retaining session information.
 */
class WebStudio_Admin_Watch_Session_Visibility {
	/**
	 * Scan eligible IDs in small batches. Core exposes no supported SQL session count.
	 * Only the requested page's WP_User objects are retained; tokens never leave this service.
	 */
	public function page( $roles, $search = '', $page = 1, $per_page = 20 ) {
		$result = array( 'users' => array(), 'counts' => array(), 'total' => 0, 'sessions' => 0, 'eligible' => 0, 'page' => max( 1, absint( $page ) ) );
		if ( ! $roles ) {
			return $result;
		}
		$per_page = min( 100, max( 1, absint( $per_page ) ) );
		$start = ( $result['page'] - 1 ) * $per_page;
		$offset = 0;
		do {
			$ids = get_users( array(
				'role__in' => array_values( $roles ), 'fields' => 'ID', 'number' => 100, 'offset' => $offset,
				'orderby' => array( 'display_name' => 'ASC', 'ID' => 'ASC' ),
				'search' => $search ? '*' . $search . '*' : '',
				'search_columns' => array( 'display_name', 'user_login', 'user_email' ),
			) );
			$result['eligible'] += count( $ids );
			$counts = $this->counts_for_users( $ids );
			foreach ( $ids as $id ) {
				if ( empty( $counts[ $id ] ) ) {
					continue;
				}
				if ( $result['total'] >= $start && count( $result['counts'] ) < $per_page ) {
					$result['counts'][ $id ] = $counts[ $id ];
				}
				++$result['total'];
				$result['sessions'] += $counts[ $id ];
			}
			$offset += 100;
		} while ( 100 === count( $ids ) );
		$last_page = max( 1, (int) ceil( $result['total'] / $per_page ) );
		if ( $result['page'] > $last_page ) {
			return $this->page( $roles, $search, $last_page, $per_page );
		}
		if ( $result['counts'] ) {
			$result['users'] = get_users( array( 'include' => array_keys( $result['counts'] ), 'number' => $per_page, 'orderby' => array( 'display_name' => 'ASC', 'ID' => 'ASC' ) ) );
		}
		return $result;
	}
	/**
	 * Return valid-session counts keyed by user ID.
	 *
	 * WP_Session_Tokens::get_all() delegates validity to the configured core
	 * session manager. AdminWatch Central intentionally reads only the count; token
	 * verifiers and session metadata are never retained or exposed.
	 *
	 * @param array<int,int> $user_ids User IDs in AdminWatch Central's access scope.
	 * @return array<int,int>
	 */
	public function counts_for_users( $user_ids ) {
		$counts = array();

		foreach ( array_unique( array_map( 'absint', (array) $user_ids ) ) as $user_id ) {
			if ( ! $user_id ) {
				continue;
			}

			$sessions = WP_Session_Tokens::get_instance( $user_id )->get_all();
			$count    = is_array( $sessions ) ? count( $sessions ) : 0;

			if ( $count ) {
				$counts[ $user_id ] = $count;
			}
		}

		return $counts;
	}
}