<?php
namespace AntivirusAI\V1;

/** Scan accounting is durable before queue progress. Replaying a marker is idempotent. */
final class WorkCheckpoint {
	public static function commit( Store $store, array &$scan, array $job, string $state, int $cursor, callable $save ): void {
		if ( ( $job['scan_id'] ?? null ) !== ( $scan['id'] ?? null ) || ! ctype_digit( (string) ( $job['id'] ?? '' ) ) || (int) $job['id'] < 1 || ! in_array( $state, array( 'pending', 'done', 'failed', 'skipped' ), true ) || $cursor < 0 ) {
			throw new \RuntimeException( 'Invalid server-owned scan work checkpoint.' );
		}
		$scan['work_checkpoint'] = array( 'version' => 1, 'scan_id' => $scan['id'], 'job_id' => (int) $job['id'], 'state' => $state, 'cursor' => $cursor );
		$save( $scan );
		self::resume( $store, $scan );
	}
	public static function resume( Store $store, array &$scan ): void {
		if ( ! array_key_exists( 'work_checkpoint', $scan ) ) { return; }
		$marker = $scan['work_checkpoint'];
		if ( ! is_array( $marker ) || 1 !== ( $marker['version'] ?? null ) || ( $marker['scan_id'] ?? null ) !== ( $scan['id'] ?? null ) || ! is_int( $marker['job_id'] ?? null ) || $marker['job_id'] < 1 || ! is_int( $marker['cursor'] ?? null ) || $marker['cursor'] < 0 || ! in_array( $marker['state'] ?? null, array( 'pending', 'done', 'failed', 'skipped' ), true ) ) {
			throw new \RuntimeException( 'Saved scan work checkpoint is invalid; no queue progress was applied.' );
		}
		$store->finishWorkForScan( $scan['id'], $marker['job_id'], $marker['state'], $marker['cursor'] );
		// The next scan save clears this marker. A crash before that save replays only
		// this already-accounted queue transition, never the completed file analysis.
		unset( $scan['work_checkpoint'] );
	}
}