<?php
/**
 * Scan history and trend (F-MONITOR-01, 02).
 *
 * @package ForensixDigital
 */

declare(strict_types=1);

namespace ForensixDigital\Apps\Monitor;

defined( 'ABSPATH' ) || exit;

use ForensixDigital\Services\Findings\FindingStore;

/**
 * Turns the stored scans into rows with plain numbers: what was new, what was resolved and how
 * many findings were open when the scan ended. The screen lists the last 50 scans.
 */
final class HistoryReport {

	public const LIMIT = 50;

	/**
	 * Rows for the screen.
	 *
	 * @param array<int, array{id: int, app: string, status: string, job_id: int, stats: array<string, mixed>, started_at: string, finished_at: string|null}> $scans Scans, newest first.
	 * @return array<int, array{id: int, status: string, started_at: string, finished_at: string|null, new: int, resolved: int, open: int}>
	 */
	public static function rows( array $scans ): array {
		$rows = array();
		foreach ( $scans as $scan ) {
			$rows[] = array(
				'id'          => $scan['id'],
				'status'      => $scan['status'],
				'started_at'  => $scan['started_at'],
				'finished_at' => $scan['finished_at'],
				'new'         => (int) ( $scan['stats']['new'] ?? 0 ),
				'resolved'    => (int) ( $scan['stats']['resolved'] ?? 0 ),
				'open'        => (int) ( $scan['stats']['open'] ?? 0 ),
			);
		}
		return $rows;
	}

	/**
	 * The plain list for one scan: what is new and what was resolved.
	 *
	 * @param array{id: int, status: string, started_at: string, finished_at: string|null, stats: array<string, mixed>} $scan    Scan.
	 * @param array{new: array<int, array<string, mixed>>, resolved: array<int, array<string, mixed>>}                  $changes From FindingStore::changes().
	 * @return array<string, mixed>
	 */
	public static function changes( array $scan, array $changes ): array {
		$pick = static fn( array $finding ): array => array(
			'id'       => $finding['id'],
			'title'    => $finding['title'],
			'severity' => $finding['severity'],
			'target'   => $finding['target'],
			'label'    => $finding['source_label'],
		);
		return array(
			'scan'           => array(
				'id'         => $scan['id'],
				'started_at' => $scan['started_at'],
			),
			'new'            => array_map( $pick, $changes['new'] ),
			'resolved'       => array_map( $pick, $changes['resolved'] ),
			'new_total'      => (int) ( $scan['stats']['new'] ?? 0 ),
			'resolved_total' => (int) ( $scan['stats']['resolved'] ?? 0 ),
		);
	}

	/**
	 * How the last two completed scans compare: "better", "worse", "same" or "" with fewer than two.
	 *
	 * @param array<int, array{status: string, open: int}> $rows Rows from rows(), newest first.
	 */
	public static function trend( array $rows ): string {
		$done = array_values( array_filter( $rows, static fn( array $row ): bool => FindingStore::SCAN_COMPLETED === $row['status'] ) );
		if ( count( $done ) < 2 ) {
			return '';
		}
		if ( $done[0]['open'] === $done[1]['open'] ) {
			return 'same';
		}
		return $done[0]['open'] < $done[1]['open'] ? 'better' : 'worse';
	}

	/**
	 * Number of scans to show.
	 */
	public static function limit(): int {
		return self::LIMIT;
	}
}