<?php
/**
 * @package       Bicycle
 * @author        Egor Isaev
 * @description   FileLogReader.php
 * @copyright (c) 24/06/2026
 */

namespace System\Classes;

/**
 * Чтение логов из файлов {channel}-{Y-m-d}.log в каталоге Log::directory().
 * Парсит строки формата "[Y-m-d H:i:s] LEVEL: message".
 */
class FileLogReader implements LogReader
{
    /** @var int Максимум записей в выдаче */
    public int $limit = 1000;

    /** Регулярка строки лога: дата-время, уровень, сообщение */
    private const LINE = '/^\[(\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2})\] (\w+): (.*)$/';

    /**
     * {@inheritDoc}
     */
    public function read(array $filters = []): array
    {
        $date    = $filters['date']    ?? date('Y-m-d');
        $channel = $filters['channel'] ?? 'action';
        $level   = strtolower((string)($filters['level'] ?? ''));
        $q       = (string)($filters['q'] ?? '');

        $channels = $channel === 'all' ? ['action', 'error'] : [$channel];
        $entries  = [];

        foreach ($channels as $ch) {
            $file = Log::directory() . '/' . $ch . '-' . $date . '.log';
            if (!is_file($file)) {
                continue;
            }

            foreach (file($file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) as $line) {
                if (!preg_match(self::LINE, $line, $m)) {
                    continue;
                }

                $entry = [
                    'datetime' => $m[1],
                    'level'    => strtolower($m[2]),
                    'message'  => $m[3],
                    'channel'  => $ch,
                ];

                if ($level !== '' && $entry['level'] !== $level) {
                    continue;
                }
                if ($q !== '' && stripos($line, $q) === false) {
                    continue;
                }

                $entries[] = $entry;
            }
        }

        // Новые сверху (datetime сравним лексикографически).
        usort($entries, static fn($a, $b) => strcmp($b['datetime'], $a['datetime']));

        return array_slice($entries, 0, $this->limit);
    }

    /**
     * {@inheritDoc}
     */
    public function dates(): array
    {
        $dir = Log::directory();
        if (!is_dir($dir)) {
            return [];
        }

        $files = array_merge(
            glob($dir . '/action-*.log') ?: [],
            glob($dir . '/error-*.log') ?: []
        );

        $dates = [];
        foreach ($files as $file) {
            if (preg_match('/-(\d{4}-\d{2}-\d{2})\.log$/', $file, $m)) {
                $dates[$m[1]] = true;
            }
        }

        $dates = array_keys($dates);
        rsort($dates); // новые даты сверху

        return $dates;
    }
}