<?php
/**
 * Local list of recent PHP fatal errors.
 *
 * @package Keepwatch
 */

namespace Keepwatch\Errors;

defined( 'ABSPATH' ) || exit;

/**
 * Stored in a single non-autoloaded option, de-duplicated by fingerprint and capped,
 * so a crash loop cannot grow the database.
 */
final class ErrorStore {

	public const OPTION = 'keepwatch_errors';
	public const MAX    = 50;

	/**
	 * Record an (already redacted) error.
	 *
	 * @param string $type    Human readable error type, e.g. "E_ERROR".
	 * @param string $message Redacted message.
	 * @param string $file    Redacted file path.
	 * @param int    $line    Line number.
	 * @param int    $now     Unix timestamp.
	 */
	public function add( string $type, string $message, string $file, int $line, int $now ): void {
		$errors      = $this->all();
		$fingerprint = md5( $type . '|' . $file . '|' . $line . '|' . $message );

		if ( isset( $errors[ $fingerprint ] ) ) {
			++$errors[ $fingerprint ]['count'];
			$errors[ $fingerprint ]['last_seen'] = $now;
		} else {
			$errors[ $fingerprint ] = array(
				'type'       => $type,
				'message'    => substr( $message, 0, 500 ),
				'file'       => $file,
				'line'       => $line,
				'count'      => 1,
				'first_seen' => $now,
				'last_seen'  => $now,
			);
		}

		// Newest first; drop the oldest beyond the cap.
		uasort(
			$errors,
			static function ( array $a, array $b ): int {
				return $b['last_seen'] <=> $a['last_seen'];
			}
		);
		$errors = array_slice( $errors, 0, self::MAX, true );

		update_option( self::OPTION, $errors, false );
	}

	/**
	 * All stored errors, newest first.
	 *
	 * @return array<string, array{type: string, message: string, file: string, line: int, count: int, first_seen: int, last_seen: int}>
	 */
	public function all(): array {
		$errors = get_option( self::OPTION, array() );
		return is_array( $errors ) ? $errors : array();
	}

	/**
	 * Errors seen after a timestamp.
	 *
	 * @param int $since Unix timestamp.
	 * @return array<string, array{type: string, message: string, file: string, line: int, count: int, first_seen: int, last_seen: int}>
	 */
	public function since( int $since ): array {
		return array_filter(
			$this->all(),
			static function ( array $error ) use ( $since ): bool {
				return (int) $error['last_seen'] >= $since;
			}
		);
	}

	/**
	 * Forget all errors.
	 */
	public function clear(): void {
		delete_option( self::OPTION );
	}
}