<?php
/**
 * Scheduled jobs: daily log cleanup and re-normalizing codes after matching settings change.
 *
 * @package NovoVerify
 */

defined( 'ABSPATH' ) || exit;

/**
 * Registers and runs the WP-Cron jobs.
 */
final class NovoVerify_Cron {

	/**
	 * Daily cleanup hook.
	 */
	const CLEANUP_HOOK = 'novoverify_daily_cleanup';

	/**
	 * Re-normalization hook (single events, chained until done).
	 */
	const RENORMALIZE_HOOK = 'novoverify_renormalize';

	/**
	 * Option that stores the re-normalization progress.
	 */
	const RENORMALIZE_OPTION = 'novoverify_renormalize_state';

	/**
	 * Codes processed per re-normalization run.
	 */
	const RENORMALIZE_BATCH = 2000;

	/**
	 * Registers hooks.
	 */
	public function __construct() {
		add_action( self::CLEANUP_HOOK, array( __CLASS__, 'cleanup' ) );
		add_action( self::RENORMALIZE_HOOK, array( __CLASS__, 'renormalize' ) );
		add_action( 'init', array( __CLASS__, 'ensure_scheduled' ) );
		add_action( 'update_option_' . NovoVerify_Config::OPTION_SETTINGS, array( __CLASS__, 'on_settings_updated' ), 10, 2 );
		add_action( 'add_option_' . NovoVerify_Config::OPTION_SETTINGS, array( __CLASS__, 'on_settings_added' ), 10, 2 );
	}

	/**
	 * Schedules the daily cleanup if it is missing (e.g. after a migration).
	 */
	public static function ensure_scheduled() {
		if ( ! wp_next_scheduled( self::CLEANUP_HOOK ) ) {
			wp_schedule_event( time() + HOUR_IN_SECONDS, 'daily', self::CLEANUP_HOOK );
		}
	}

	/**
	 * Removes all scheduled events of the plugin.
	 */
	public static function unschedule_all() {
		wp_clear_scheduled_hook( self::CLEANUP_HOOK );
		wp_clear_scheduled_hook( self::RENORMALIZE_HOOK );
	}

	/**
	 * Deletes check log rows older than the retention period and stale import files.
	 */
	public static function cleanup() {
		$days = (int) NovoVerify_Settings::get( 'log_retention' );

		if ( $days > 0 ) {
			// Batches keep each query short; the limit keeps one run from taking too long.
			for ( $i = 0; $i < 50; $i++ ) {
				if ( NovoVerify_DB::delete_checks_older_than( $days ) < 1 ) {
					break;
				}
			}
		}

		if ( class_exists( 'NovoVerify_Import' ) ) {
			NovoVerify_Import::delete_stale_files();
		}

		/**
		 * Fires after the daily cleanup.
		 */
		do_action( 'novoverify_after_cleanup' );
	}

	/**
	 * Starts re-normalizing when the matching settings change.
	 *
	 * @param mixed $old_value Previous settings.
	 * @param mixed $value     New settings.
	 */
	public static function on_settings_updated( $old_value, $value ) {
		$old_value = array_merge( NovoVerify_Settings::defaults(), is_array( $old_value ) ? $old_value : array() );
		$value     = array_merge( NovoVerify_Settings::defaults(), is_array( $value ) ? $value : array() );

		if ( (bool) $old_value['case_sensitive'] !== (bool) $value['case_sensitive']
			|| (bool) $old_value['ignore_separators'] !== (bool) $value['ignore_separators'] ) {
			self::start_renormalize();
		}
	}

	/**
	 * Same as on_settings_updated() for the very first save.
	 *
	 * @param string $option Option name.
	 * @param mixed  $value  New settings.
	 */
	public static function on_settings_added( $option, $value ) {
		self::on_settings_updated( NovoVerify_Settings::defaults(), $value );
	}

	/**
	 * Starts (or restarts) re-normalizing all stored codes.
	 */
	public static function start_renormalize() {
		update_option(
			self::RENORMALIZE_OPTION,
			array(
				'after_id'  => 0,
				'updated'   => 0,
				'conflicts' => 0,
				'done'      => false,
				'total'     => NovoVerify_DB::count_codes(),
			),
			false
		);
		wp_clear_scheduled_hook( self::RENORMALIZE_HOOK );

		// The first batch runs right away, so small code lists are finished immediately.
		self::renormalize();
	}

	/**
	 * Processes one batch and schedules the next one.
	 */
	public static function renormalize() {
		$state = get_option( self::RENORMALIZE_OPTION );
		if ( ! is_array( $state ) || ! empty( $state['done'] ) ) {
			return;
		}

		$rows = NovoVerify_DB::get_code_batch( (int) $state['after_id'], self::RENORMALIZE_BATCH );

		foreach ( $rows as $row ) {
			$state['after_id'] = (int) $row->id;
			$source            = '' !== (string) $row->display_code ? (string) $row->display_code : (string) $row->code;
			$code              = NovoVerify_Codes::normalize_with_settings( $source );

			if ( $code === $row->code ) {
				continue;
			}
			// A code that would become invalid, or equal to another code, keeps its old value.
			if ( NovoVerify_Codes::is_valid( $code ) && NovoVerify_DB::set_code_value( (int) $row->id, $code ) ) {
				++$state['updated'];
			} else {
				++$state['conflicts'];
			}
		}

		if ( count( $rows ) < self::RENORMALIZE_BATCH ) {
			$state['done'] = true;
		} else {
			wp_schedule_single_event( time(), self::RENORMALIZE_HOOK );
		}

		update_option( self::RENORMALIZE_OPTION, $state, false );
	}

	/**
	 * Current re-normalization state, or null when none ran.
	 *
	 * @return array|null
	 */
	public static function renormalize_state() {
		$state = get_option( self::RENORMALIZE_OPTION );
		return is_array( $state ) ? $state : null;
	}
}