<?php
/**
 * Plugin bootstrap and service container.
 *
 * @package Shiftora\Core
 */

declare(strict_types=1);

namespace Shiftora\Core;

use Shiftora\Admin\AdminMenu;
use Shiftora\Admin\AdminPostHandlers;
use Shiftora\Admin\Assets;
use Shiftora\Admin\RetiredPages;
use Shiftora\Api\AdminAjaxProxy;
use Shiftora\Api\RestRegistrar;
use Shiftora\Core\ServiceFactory;
use Shiftora\Logging\MigrationLogger;
use Shiftora\Migration\MigrationJob;
use Shiftora\Migration\MigrationStatus;
use Shiftora\Migration\SessionHandoff;
use Shiftora\Migration\StallRecovery;
use Shiftora\Support\DataDirectory;

// Prevent direct file access.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Central plugin object, bootstrapped once on `plugins_loaded`.
 */
final class Plugin {

	/** @var self|null Singleton instance. */
	private static ?self $instance = null;

	/** @var Loader Hook loader. */
	private Loader $loader;

	/** Private constructor, use Plugin::init(). */
	private function __construct() {
		$this->loader = new Loader();
		$this->register_services();
	}

	/** Initializes the plugin on `plugins_loaded`; bootstraps once. */
	public static function init(): void {
		if ( null === self::$instance ) {
			self::$instance = new self();
			self::$instance->loader->run();
		}
	}

	/** Returns the singleton, or null before init() runs. */
	public static function instance(): ?self {
		return self::$instance;
	}

	/** Registers all service hooks with the Loader. */
	private function register_services(): void {
		// Role-key repair that runs once a cross-prefix pull flags it pending.
		$this->loader->add_action( 'init', $this, 'repair_prefix_bound_access_keys', 5 );

		// Covers sites copied in rather than activated. Loader only takes object callbacks.
		add_action( 'admin_init', [ Installer::class, 'maybe_upgrade' ] );
		add_action( 'admin_init', [ DataDirectory::class, 'adopt_legacy_once' ] );

		// Stall recovery: custom two-minute cron interval.
		add_filter( 'cron_schedules', static function ( array $schedules ): array {
			if ( ! isset( $schedules[ StallRecovery::CRON_INTERVAL ] ) ) {
				$schedules[ StallRecovery::CRON_INTERVAL ] = [
					'interval' => 120,
					'display'  => __( 'Every 2 Minutes', 'shiftora' ),
				];
			}
			return $schedules;
		} );

		// Schedules the event if it is not already queued.
		add_action( 'admin_init', [ StallRecovery::class, 'schedule_cron' ] );

		add_action( StallRecovery::CRON_HOOK, static function (): void {
			global $wpdb;
			StallRecovery::run(
				$wpdb,
				static fn( int $migration_id ) => ServiceFactory::migration_engine()->finish_stuck_cancel( $migration_id )
			);
		} );

		// Re-trigger recovery for failed migrations that hold a recovery lock and are not yet recovered.
		add_action( StallRecovery::CRON_HOOK, static function (): void {
			global $wpdb;
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery -- custom table, fresh read required
			$rows = $wpdb->get_results(
				$wpdb->prepare(
					'SELECT id FROM %i WHERE status = %s',
					$wpdb->prefix . 'shiftora_migrations',
					MigrationStatus::Failed->value
				)
			);
			if ( empty( $rows ) ) {
				return;
			}
			$recovery = ServiceFactory::recovery_manager();
			foreach ( $rows as $row ) {
				$migration_id = (int) $row->id;
				$lock = $recovery->get_lock( $migration_id );
				if ( null === $lock ) {
					continue;
				}
				// Skip runs recovery already attempted or declined, or they would be re-failed every two minutes.
				if ( in_array( $lock['status'] ?? '', [ 'recovery_failed', 'recovery_skipped' ], true ) ) {
					continue;
				}
				if ( function_exists( 'as_has_scheduled_action' )
					&& as_has_scheduled_action( 'shiftora_auto_recovery', [ $migration_id ], 'shiftora' )
				) {
					continue;
				}
				$recovery->mark_failed( $migration_id, 'Auto-recovery re-triggered by cron after stall.' );
			}
		} );

		if ( is_admin() ) {
			$menu    = new AdminMenu();
			$assets  = new Assets();
			$retired = new RetiredPages();
			$this->loader->add_action( 'admin_menu', $menu, 'register' );
			$this->loader->add_action( 'admin_head', $menu, 'prune_sidebar' );
			$this->loader->add_action( 'admin_enqueue_scripts', $assets, 'enqueue', 10, 1 );
			$this->loader->add_filter( 'admin_body_class', $assets, 'body_class', 10, 1 );
			$this->loader->add_filter( 'wp_auth_check_load', $assets, 'auth_check_load', 10, 2 );
		}

		// A sign-out or a password reset revokes every secret that could sign a page back in.
		$handoff = new SessionHandoff();
		$this->loader->add_action( 'wp_logout', $handoff, 'forget_all' );
		$this->loader->add_action( 'after_password_reset', $handoff, 'forget_all' );

		if ( is_admin() ) {

			// Fires just before WordPress refuses an unregistered page= slug, the last point to redirect a retired one.
			$this->loader->add_action( 'admin_page_access_denied', $retired, 'maybe_redirect' );
		}

		// Detects unfinished migrations, offers recovery and handles scheduled auto-recovery.
		$recovery = ServiceFactory::recovery_manager();
		$recovery->register_hooks();
		$this->loader->add_action( 'admin_init', $recovery, 'detect_and_offer_recovery' );

		// Settings forms and the recovery notice post to admin-post.php; each handler checks its own nonce and capability.
		AdminPostHandlers::register();

		// REST API.
		$rest = new RestRegistrar();
		$this->loader->add_action( 'rest_api_init', $rest, 'register_routes' );

		// Admin-AJAX fallback for when the remote REST API returns 404 (broken permalinks, a security plugin).
		add_action( 'init', [ AdminAjaxProxy::class, 'register' ] );

		// File downloads. On admin_init because rest_api_init does not fire on admin-post.php requests.
		add_action( 'admin_init', static function (): void {
			$export_file = new \Shiftora\Api\Endpoints\ExportFileEndpoint();
			add_action( 'admin_post_shiftora_export_file', [ $export_file, 'serve_download' ] );

			global $wpdb;
			$backup = new \Shiftora\Api\Endpoints\BackupEndpoint( $wpdb );
			add_action( 'admin_post_shiftora_download_backup', [ $backup, 'serve_download' ] );
		} );

		// Chunk processing hooks.
		MigrationJob::register();
		MigrationJob::register_file_hook();

		// Daily prune of log rows older than 30 days.
		add_action( 'admin_init', static function (): void {
			if ( ! wp_next_scheduled( 'shiftora_prune_logs' ) ) {
				wp_schedule_event( time(), 'daily', 'shiftora_prune_logs' );
			}
		} );
		add_action( 'shiftora_prune_logs', static function (): void {
			MigrationLogger::prune( 30 );
		} );
	}

	/** Repairs role and capability keys after a cross-prefix import; only scans when a pull flagged it pending, and clears the flag however it exits. */
	public function repair_prefix_bound_access_keys(): void {
		if ( ! get_option( 'shiftora_repair_prefix_pending' ) ) {
			return;
		}

		try {
			$this->repair_prefix_bound_access_keys_inner();
		} finally {
			delete_option( 'shiftora_repair_prefix_pending' );
		}
	}

	/** Scan-and-repair pass, only called when repair is pending. */
	private function repair_prefix_bound_access_keys_inner(): void {
		global $wpdb;

		if ( ! ( $wpdb instanceof \wpdb ) ) {
			return;
		}

		$local_prefix   = (string) $wpdb->prefix;
		$options_table  = $wpdb->prefix . 'options';
		$usermeta_table = $wpdb->prefix . 'usermeta';
		$role_option    = $local_prefix . 'user_roles';

		if ( null === get_option( $role_option, null ) ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery -- the roles row of another prefix, fresh read required
			$foreign_roles = $wpdb->get_row(
				$wpdb->prepare(
					'SELECT option_value FROM %i WHERE option_name LIKE %s AND option_name <> %s ORDER BY option_id DESC LIMIT 1',
					$options_table,
					'%' . $wpdb->esc_like( 'user_roles' ),
					$role_option
				),
				ARRAY_A
			);

			if ( is_array( $foreign_roles ) && isset( $foreign_roles['option_value'] ) ) {
				update_option( $role_option, maybe_unserialize( $foreign_roles['option_value'] ), false );
			}
		}

		$local_like = $wpdb->esc_like( $local_prefix ) . '%';
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery -- the capability rows of another prefix, fresh read required
		$foreign_meta = $wpdb->get_results(
			$wpdb->prepare(
				'SELECT user_id, meta_key FROM %i WHERE (meta_key LIKE %s OR meta_key LIKE %s) AND meta_key NOT LIKE %s',
				$usermeta_table,
				'%' . $wpdb->esc_like( 'capabilities' ),
				'%' . $wpdb->esc_like( 'user_level' ),
				$local_like
			),
			ARRAY_A
		);

		if ( ! is_array( $foreign_meta ) ) {
			return;
		}

		foreach ( $foreign_meta as $row ) {
			$user_id  = (int) ( $row['user_id'] ?? 0 );
			$meta_key = (string) ( $row['meta_key'] ?? '' );
			if ( $user_id <= 0 || '' === $meta_key ) {
				continue;
			}

			if ( ! preg_match( '/^(?:.+?_)?((?:\d+_)?(?:capabilities|user_level))$/', $meta_key, $matches ) ) {
				continue;
			}

			$target_key = $local_prefix . $matches[1];
			if ( ! metadata_exists( 'user', $user_id, $target_key ) && metadata_exists( 'user', $user_id, $meta_key ) ) {
				update_user_meta( $user_id, $target_key, get_user_meta( $user_id, $meta_key, true ) );
			}

			delete_user_meta( $user_id, $meta_key );
			clean_user_cache( $user_id );
		}
	}
}