folio/src/TrendingParser.php

<?php

declare(strict_types=1);

/**
 * Lit les logs Apache et retourne les chemins /post/* les plus consultés
 * sur une fenêtre temporelle donnée, en comptant les visiteurs uniques (IPs distinctes)
 * avec code HTTP 200 uniquement.
 */
class TrendingParser
{
    // Apache COMBINED : IP - - [timestamp] "METHOD /path HTTP/x" STATUS bytes "ref" "ua"
    private const RE = '/^(\S+) \S+ \S+ \[(\d{2}\/\w+\/\d{4}:\d{2}:\d{2}:\d{2} [+-]\d{4})\] "[A-Z-]+ ([^\s"?]+)[^"]*" (\d{3}) /';

    public function __construct(
        private string $logDir,
        private string $pattern,
    ) {
    }

    /**
     * Retourne les $limit chemins les plus consultés depuis $cutoff,
     * triés par nombre décroissant de visiteurs uniques.
     *
     * @param  list<string>         $prefixes  ex. ['/post/'], ['/post/', '/book/']
     * @return array<string, int>              chemin => nb visiteurs uniques
     */
    public function top(int $cutoff, int $limit = 50, array $prefixes = ['/post/']): array
    {
        $visitors = []; // [path][ip] = true

        foreach ($this->logFiles($cutoff) as $file) {
            $this->parseFile($file, $cutoff, $visitors, $prefixes);
        }

        $counts = [];
        foreach ($visitors as $path => $ips) {
            $counts[$path] = count($ips);
        }
        arsort($counts);

        return array_slice($counts, 0, $limit, true);
    }

    /**
     * Parse une seule fois les logs et retourne les tops séparés par préfixe.
     * Plus efficace que plusieurs appels à top() sur la même période.
     *
     * @param  array<string, int>           $limits   préfixe => limite
     * @return array<string, array<string, int>>       préfixe => (chemin => visiteurs)
     */
    public function topGrouped(int $cutoff, array $limits): array
    {
        $prefixes = array_keys($limits);
        $visitors = []; // [path][ip] = true

        foreach ($this->logFiles($cutoff) as $file) {
            $this->parseFile($file, $cutoff, $visitors, $prefixes);
        }

        $result = array_fill_keys($prefixes, []);
        foreach ($visitors as $path => $ips) {
            foreach ($prefixes as $prefix) {
                if (str_starts_with($path, $prefix)) {
                    $result[$prefix][$path] = count($ips);
                    break;
                }
            }
        }

        foreach ($prefixes as $prefix) {
            arsort($result[$prefix]);
            $result[$prefix] = array_slice($result[$prefix], 0, $limits[$prefix], true);
        }

        return $result;
    }

    public function isReadable(): bool
    {
        return count($this->logFiles(time() - 86400)) > 0;
    }

    // ── Fichiers de log ───────────────────────────────────────────────────────

    /** @return list<array{path:string,type:string}> */
    private function logFiles(int $cutoff): array
    {
        $files  = [];
        $oldest = $cutoff - 86400; // une journée de marge pour les rotations

        foreach (glob($this->logDir . '/' . $this->pattern) ?: [] as $base) {
            if (str_ends_with($base, '.gz') || preg_match('/\.\d+$/', $base)) {
                continue;
            }
            foreach (array_merge([$base], glob($base . '.*') ?: []) as $path) {
                if ($path !== $base && filemtime($path) < $oldest) {
                    continue;
                }
                if (!is_readable($path)) {
                    continue;
                }
                if (str_ends_with($path, '.tar.gz')) {
                    $files[] = ['path' => $path, 'type' => 'tgz'];
                } elseif (str_ends_with($path, '.gz')) {
                    $files[] = ['path' => $path, 'type' => 'gz'];
                } else {
                    $files[] = ['path' => $path, 'type' => 'plain'];
                }
            }
        }

        return $files;
    }

    // ── Parsing ───────────────────────────────────────────────────────────────

    private static function parseTimestamp(string $raw): int
    {
        if (!preg_match('/(\d{2})\/(\w{3})\/(\d{4}):(\d{2}:\d{2}:\d{2}) ([+-]\d{4})/', $raw, $m)) {
            return 0;
        }
        return (int) strtotime("{$m[1]} {$m[2]} {$m[3]} {$m[4]} {$m[5]}");
    }

    /**
     * @param array<string, array<string, true>> $visitors
     * @param list<string>                        $prefixes
     */
    private function parseLine(string $line, int $cutoff, array &$visitors, array $prefixes): void
    {
        if (!preg_match(self::RE, $line, $m)) {
            return;
        }
        [, $ip, $ts, $path, $status] = $m;

        if ($status !== '200') {
            return;
        }
        if (self::parseTimestamp($ts) < $cutoff) {
            return;
        }
        foreach ($prefixes as $prefix) {
            if (str_starts_with($path, $prefix) && strlen($path) > strlen($prefix)) {
                $visitors[$path][$ip] = true;
                break;
            }
        }
    }

    /**
     * @param array<string, array<string, true>> $visitors
     * @param list<string>                        $prefixes
     */
    private function parseFile(array $file, int $cutoff, array &$visitors, array $prefixes): void
    {
        if ($file['type'] === 'tgz') {
            try {
                $phar = new PharData($file['path']);
                foreach ($phar as $entry) {
                    $content = @file_get_contents('phar://' . $file['path'] . '/' . $entry->getFilename());
                    if ($content === false) {
                        continue;
                    }
                    foreach (explode("\n", $content) as $line) {
                        $this->parseLine($line, $cutoff, $visitors, $prefixes);
                    }
                }
            } catch (\Exception) {
            }
        } elseif ($file['type'] === 'gz') {
            $h = @gzopen($file['path'], 'rb');
            if (!$h) {
                return;
            }
            while (!gzeof($h)) {
                $line = gzgets($h, 8192);
                if ($line !== false) {
                    $this->parseLine($line, $cutoff, $visitors, $prefixes);
                }
            }
            gzclose($h);
        } else {
            $h = @fopen($file['path'], 'rb');
            if (!$h) {
                return;
            }
            while (($line = fgets($h)) !== false) {
                $this->parseLine($line, $cutoff, $visitors, $prefixes);
            }
            fclose($h);
        }
    }
}