<?php

// 0) Umgebung / Domains / Error-Level
require_once __DIR__ . "/config.php";

// -----------------------------------------------------------
// Session starten
// -----------------------------------------------------------
if (php_sapi_name() !== 'cli') {
    if (session_status() === PHP_SESSION_NONE) {

        session_name('usbcheck_session');

        session_set_cookie_params([
            'lifetime' => 0,
            'path'     => '/',
            'domain'   => '',
            'secure'   => (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off'),
            'httponly' => true,
            'samesite' => 'Lax',
        ]);

        session_start();
    }
}

// -----------------------------------------------------------
// Helper: Browser-Sprache aus HTTP_ACCEPT_LANGUAGE bestimmen
// -----------------------------------------------------------
function usb_detect_browser_lang(array $availableLangs): ?string
{
    if (empty($availableLangs)) {
        return null;
    }

    $header = $_SERVER['HTTP_ACCEPT_LANGUAGE'] ?? '';
    if ($header === '') {
        return null;
    }

    // z.B. "de-DE,de;q=0.9,en-US;q=0.8,en;q=0.7,it;q=0.6"
    $parts = explode(',', $header);

    foreach ($parts as $part) {
        $part = trim($part);
        if ($part === '') {
            continue;
        }

        // Sprache vor dem ; nehmen (z.B. "de-DE" oder "en-US")
        $langTag = strtolower(explode(';', $part)[0]);

        if ($langTag === '') {
            continue;
        }

        // 2-Buchstaben-Code extrahieren
        $code2 = substr($langTag, 0, 2);

        if (preg_match('/^[a-z]{2}$/', $code2) && isset($availableLangs[$code2])) {
            return $code2;
        }
    }

    return null;
}

// -----------------------------------------------------------
// 1) Sprache aus ?lang lesen (nur 2-Buchstaben-Code zulassen)
// -----------------------------------------------------------
$requestedLang = $_GET['lang'] ?? null;

if (is_string($requestedLang)) {
    $requestedLang = strtolower($requestedLang);
    if (!preg_match('/^[a-z]{2}$/', $requestedLang)) {
        $requestedLang = null;
    }
} else {
    $requestedLang = null;
}

// -----------------------------------------------------------
// 2) Verfügbare JSON-Sprachen erkennen
// -----------------------------------------------------------
$i18nDir = __DIR__ . '/../public/assets/i18n';

$langFiles = [];
if (is_dir($i18nDir)) {
    $langFiles = glob($i18nDir . '/*.json') ?: [];
}

$availableLangs = [];

// Alle vorhandenen JSONs einsammeln
foreach ($langFiles as $file) {
    $raw = @file_get_contents($file);
    if ($raw === false) {
        error_log('i18n: Konnte Datei nicht lesen: ' . $file);
        continue;
    }

    $json = json_decode($raw, true);
    if (!is_array($json)) {
        error_log('i18n: Ungültiges JSON in ' . $file . ' :: ' . json_last_error_msg());
        continue;
    }

    $meta = $json['meta'] ?? [];

    // Option: nur Sprachen mit enabled=false ausblenden
    if (array_key_exists('enabled', $meta) && $meta['enabled'] === false) {
        continue;
    }

    // Sprachcode bestimmen (immer 2-Buchstaben)
    $code = strtolower($meta['code'] ?? basename($file, '.json'));
    if (!preg_match('/^[a-z]{2}$/', $code)) {
        // Sonderdateien (template.json etc.) ignorieren
        continue;
    }

    $label = $meta['label'] ?? strtoupper($code);
    $flag  = $meta['flag']  ?? '🏳️';

    $availableLangs[$code] = [
        'code'  => $code,
        'label' => $label,
        'flag'  => $flag,
    ];
}

// Falls keine Sprachdateien gefunden wurden → Minimal-Fallback
if (empty($availableLangs)) {
    $availableLangs = [
        'en' => [
            'code'  => 'en',
            'label' => 'English',
            'flag'  => '🏳️',
        ],
    ];
}

// -----------------------------------------------------------
// 3) Endgültige Sprache wählen nach deiner Priorität
// -----------------------------------------------------------
$lang = null;

// 1) ?lang=xx wird bevorzugt, wenn gültig + vorhanden
if ($requestedLang && isset($availableLangs[$requestedLang])) {
    $lang = $requestedLang;
}

// 2) Sonst HTTP_ACCEPT_LANGUAGE (Browser), erste passende Sprache
if ($lang === null) {
    $browserLang = usb_detect_browser_lang($availableLangs);
    if ($browserLang !== null) {
        $lang = $browserLang;
    }
}

// 3) Wenn Browser-Sprache nicht existiert → 'en', wenn vorhanden
if ($lang === null && isset($availableLangs['en'])) {
    $lang = 'en';
}

// 4) Sonst: erste Sprache aus $availableLangs
if ($lang === null) {
    $keys = array_keys($availableLangs);
    $lang = $keys[0] ?? 'en';
}

// -----------------------------------------------------------
// 4) Aktive Sprachdatei laden
// -----------------------------------------------------------
$activeLangFile = $i18nDir . '/' . $lang . '.json';
$activeLangData = [];

if (is_readable($activeLangFile)) {
    $json = json_decode(@file_get_contents($activeLangFile), true);
    if (is_array($json)) {
        $activeLangData = $json;
    }
}

// -----------------------------------------------------------
// 5) Fallback-Sprache: immer EN, wenn vorhanden & nicht aktuell
// -----------------------------------------------------------
$fallbackLangData = [];
$fallbackFile     = $i18nDir . '/en.json';

if ($lang !== 'en' && is_readable($fallbackFile)) {
    $json = json_decode(@file_get_contents($fallbackFile), true);
    if (is_array($json)) {
        $fallbackLangData = $json;
    }
}

// -----------------------------------------------------------
// 6) Globale i18n-Struktur bereitstellen
// -----------------------------------------------------------
$GLOBALS['lang']           = $lang;
$GLOBALS['availableLangs'] = $availableLangs;

$GLOBALS['i18n'] = [
    'current'  => $activeLangData,
    'fallback' => $fallbackLangData,
];

// -----------------------------------------------------------
// 7) Rest des Systems laden
// -----------------------------------------------------------
require_once __DIR__ . "/db.php";
require_once __DIR__ . '/../src/functions.php';