<?php
/**
 * Main plugin class: registry of scanners and extension points.
 *
 * @package CoreSeal
 */

defined( 'ABSPATH' ) || exit;

final class Coreseal_Plugin {

	/** @var Coreseal_Plugin|null */
	private static $instance = null;

	/** @var Coreseal_Scanner[] */
	private $scanners = array();

	/** @var Coreseal_Repository */
	private $repository;

	/** @var Coreseal_Exclusions */
	private $exclusions;

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

	private function __construct() {
		Coreseal_Installer::maybe_upgrade();

		$this->repository = new Coreseal_Repository();
		$this->exclusions = new Coreseal_Exclusions();

		$this->register_scanner( new Coreseal_Core_Scanner() );
		$this->register_scanner( new Coreseal_Compromise_Scanner() );
		$this->register_scanner( new Coreseal_Malware_Scanner( $this->exclusions ) );

		if ( is_admin() ) {
			new Coreseal_Admin( $this );
		}

		/**
		 * Fires once the plugin is ready. Add-ons hook here to register
		 * scanners, admin screens or scheduled tasks.
		 *
		 * @param Coreseal_Plugin $plugin Main instance.
		 */
		do_action( 'coreseal_loaded', $this );
	}

	public function register_scanner( Coreseal_Scanner $scanner ) {
		$this->scanners[ $scanner->get_id() ] = $scanner;
	}

	/**
	 * @return Coreseal_Scanner[]
	 */
	public function get_scanners(): array {
		return $this->scanners;
	}

	public function get_repository(): Coreseal_Repository {
		return $this->repository;
	}

	public function get_exclusions(): Coreseal_Exclusions {
		return $this->exclusions;
	}

	/**
	 * Runs a scanner, stores the result and returns the scan ID
	 * (or a WP_Error if the scanner is unknown).
	 *
	 * @return int|WP_Error
	 */
	public function run_scanner( string $id ) {
		if ( ! isset( $this->scanners[ $id ] ) ) {
			return new WP_Error( 'coreseal_unknown_scanner', __( 'Unknown scanner.', 'coreseal' ) );
		}

		return $this->record_result( $id, $this->scanners[ $id ]->run() );
	}

	/**
	 * Stores a scanner result (after exclusions and ignored items are
	 * removed) and returns the scan ID. Also used by step-by-step scans.
	 *
	 * @param string         $id     Scanner ID.
	 * @param array|WP_Error $result Scanner result.
	 * @return int
	 */
	public function record_result( string $id, $result ): int {
		if ( is_array( $result ) ) {
			$this->exclusions->filter_result( $id, $result );
		}

		$scan_id = $this->repository->start_scan( $id );
		$this->repository->finish_scan( $scan_id, $result );
		$this->repository->prune( $id );

		/**
		 * Fires after a scan. Used by add-ons for alerts or reports.
		 *
		 * @param int            $scan_id Scan ID.
		 * @param string         $id      Scanner ID.
		 * @param array|WP_Error $result  Result, after exclusions.
		 */
		do_action( 'coreseal_scan_finished', $scan_id, $id, $result );

		return $scan_id;
	}
}