<?php

declare(strict_types=1);

session_set_cookie_params([
    'httponly' => true,
    'samesite' => 'Strict',
    'secure' => !empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off',
    'use_strict_mode' => true,
]);
session_start();
header('Cache-Control: no-store, no-cache, must-revalidate');
header('Pragma: no-cache');
header('X-Content-Type-Options: nosniff');
header('X-Frame-Options: DENY');
header('Referrer-Policy: no-referrer');
header('Permissions-Policy: camera=(), microphone=(), geolocation=()');
header("Content-Security-Policy: default-src 'self'; style-src 'self' 'unsafe-inline'; base-uri 'self'; frame-ancestors 'none'");

require_once __DIR__ . '/inc/db.inc.php';

if (!isset($_SESSION['admin_id'])) {
    http_response_code(403);
    exit('Zugriff verweigert.');
}

$dsn = sprintf(
    'mysql:host=%s;port=%d;dbname=%s;charset=%s',
    $dbConfig['host'],
    $dbConfig['port'],
    $dbConfig['database'],
    $dbConfig['charset']
);
$pdo = new PDO($dsn, $dbConfig['username'], $dbConfig['password'], [
    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_EMULATE_PREPARES => false,
]);

$adminCheck = $pdo->prepare(
    'SELECT id FROM admin_users WHERE id = :id AND is_active = 1 LIMIT 1'
);
$adminCheck->execute([':id' => (int) $_SESSION['admin_id']]);
if ($adminCheck->fetchColumn() === false) {
    http_response_code(403);
    exit('Zugriff verweigert.');
}

function exportAccommodation(?string $value): string
{
    return match ($value) {
        'single' => 'Einzelzimmer',
        'double' => 'Doppelzimmer',
        'multi' => 'Mehrbettzimmer',
        null, '' => '',
        default => $value,
    };
}

function exportDay(mixed $value): string
{
    return match ((string) $value) {
        '1' => 'Fr.',
        '2' => 'Sa.',
        '3' => 'So.',
        default => (string) $value,
    };
}

function csvSafe(mixed $value): string
{
    $value = (string) $value;
    return preg_match('/^[=+\-@]/', $value) === 1 ? "'" . $value : $value;
}

function exportMeal(mixed $value): string
{
    return match ((string) $value) {
        'breakfast' => 'Frühstück',
        'lunch' => 'Mittagessen',
        'coffee' => 'Kaffee',
        'drinks' => 'Getränkepauschale',
        'dinner' => 'Abendessen',
        default => (string) $value,
    };
}

function exportEarlyDeparture(mixed $value): string
{
    return match ((string) $value) {
        'sat_breakfast' => 'Samstag nach dem Frühstück',
        'sat_lunch' => 'Samstag nach dem Mittagessen',
        'sat_coffee' => 'Samstag nach dem Kaffee',
        'sat_dinner' => 'Samstag nach dem Abendessen',
        'sun_breakfast' => 'Sonntag nach dem Frühstück',
        default => (string) $value,
    };
}

$rows = $pdo->query(
    'SELECT p.name, p.email, p.role, p.under_27, p.allergies,
            b.type, b.accommodation_type, b.meal_preferences, b.is_paid, b.total_price,
            b.roommate_requests, b.early_departure, b.other_notes
     FROM bookings b
     INNER JOIN participants p ON p.id = b.participant_id
     ORDER BY b.id DESC'
)->fetchAll(PDO::FETCH_ASSOC);

header('Content-Type: text/csv; charset=UTF-8');
header('Content-Disposition: attachment; filename="registrierungen.csv"');
header('Cache-Control: no-store, no-cache, must-revalidate');

echo "\xEF\xBB\xBF";
$output = fopen('php://output', 'wb');
fputcsv($output, [
    'Name',
    'E-Mail',
    'Altersgruppe',
    'Bezahlt',
    'Preis',
    'Gasttyp',
    'Zimmerart',
    'Zimmerpartner-Wunsch',
    'Frühzeitige Abreise',
    'Anwesenheitstage',
    'Mahlzeiten',
    'Allergien / Essensvorlieben',
    'Sonstiges',
], ';', '"', '\\');

foreach ($rows as $row) {
    $mealData = $row['meal_preferences'] !== null
        ? json_decode($row['meal_preferences'], true)
        : null;
    $daysRaw = is_array($mealData['days'] ?? null) ? $mealData['days'] : [];
    $mealsByDay = is_array($mealData['meals_by_day'] ?? null) ? $mealData['meals_by_day'] : [];
    if ($mealsByDay === [] && is_array($mealData['meals'] ?? null)) {
        foreach ($daysRaw as $day) {
            $mealsByDay[(string) $day] = $mealData['meals'];
        }
    }
    $days = array_map('exportDay', $daysRaw);
    $meals = [];
    foreach ($daysRaw as $day) {
        $dayMeals = array_map('exportMeal', $mealsByDay[(string) $day] ?? []);
        $dayMeals[] = 'Getränkepauschale';
        $dayMeals[] = 'Proberaumpauschale';
        $meals[] = exportDay($day) . ': ' . implode(', ', $dayMeals);
    }

    fputcsv($output, [
        csvSafe($row['name']),
        csvSafe($row['email']),
        csvSafe((int) $row['under_27'] === 1 ? 'Unter 27' : 'Ab 27'),
        csvSafe((int) $row['is_paid'] === 1 ? 'Ja' : 'Nein'),
        csvSafe(number_format((float) $row['total_price'], 2, ',', '.') . ' €'),
        csvSafe($row['role']),
        csvSafe(exportAccommodation($row['accommodation_type'])),
        csvSafe($row['roommate_requests'] ?? ''),
        csvSafe($row['early_departure'] !== null && $row['early_departure'] !== '' ? exportEarlyDeparture($row['early_departure']) : ''),
        csvSafe(implode(', ', $days)),
        csvSafe(implode(', ', $meals)),
        csvSafe($row['allergies'] ?? ''),
        csvSafe($row['other_notes'] ?? ''),
    ], ';', '"', '\\');
}

fclose($output);