<?php

declare(strict_types=1);

namespace App\Controllers;

use App\Core\I18n;
use App\Core\Locale;

class HomeController extends Controller
{
    /** Map of interest option translation key → internal identifier. */
    private const INTEREST_KEYS = [
        'visit' => 'form.interest.visit',
        'info'  => 'form.interest.info',
        'apply' => 'form.interest.apply',
    ];

    public function index(): void
    {
        if (session_status() !== PHP_SESSION_ACTIVE) {
            session_start();
        }

        $locale = LocaleController::current();

        $escapeContactValue = static fn(string $value): string
            => htmlspecialchars($value, ENT_QUOTES, 'UTF-8');

        $containsHeaderInjection = static function (string $value): bool {
            return (bool) preg_match('/[\r\n]/', $value);
        };

        // ── Pull flashed state ────────────────────────────────────────
        $formSuccess     = !empty($_SESSION['form_success']);
        $formErrors      = $_SESSION['form_errors']      ?? [];
        $formFieldErrors = $_SESSION['form_field_errors'] ?? [];
        $formData        = $_SESSION['form_data']        ?? null;
        unset(
            $_SESSION['form_success'],
            $_SESSION['form_errors'],
            $_SESSION['form_field_errors'],
            $_SESSION['form_data'],
        );

        if ($formSuccess) {
            $formData        = self::emptyFormData();
            $formFieldErrors = [];
        } elseif (!is_array($formData)) {
            $formData        = self::emptyFormData();
            $formFieldErrors = is_array($formFieldErrors) ? $formFieldErrors : [];
        } else {
            $formFieldErrors = is_array($formFieldErrors) ? $formFieldErrors : [];
        }

        // ── CSRF token ────────────────────────────────────────────────
        if (empty($_SESSION['csrf_token'])) {
            $_SESSION['csrf_token'] = bin2hex(random_bytes(32));
        }

        // ── Form processing ───────────────────────────────────────────
        if (($_SERVER['REQUEST_METHOD'] ?? 'GET') === 'POST') {
            $csrfToken = (string) ($_POST['csrf_token'] ?? '');
            if (!hash_equals($_SESSION['csrf_token'] ?? '', $csrfToken)) {
                $_SESSION['form_errors'] = ['form.error.csrf'];
                header('Location: /#kontakt');
                exit;
            }

            $formData['fname']    = trim((string) ($_POST['fname'] ?? ''));
            $formData['lname']    = trim((string) ($_POST['lname'] ?? ''));
            $formData['email']    = trim((string) ($_POST['email'] ?? ''));
            $formData['phone']    = trim((string) ($_POST['phone'] ?? ''));
            $formData['interest'] = trim((string) ($_POST['interest'] ?? 'visit'));
            $formData['message']  = trim((string) ($_POST['message'] ?? ''));

            // Honeypot: bots succeed silently.
            $honeypot = trim((string) ($_POST['website'] ?? ''));
            if ($honeypot !== '') {
                $_SESSION['form_success'] = true;
                header('Location: /#kontakt');
                exit;
            }

            // Per-field errors enable aria-invalid + aria-describedby.
            $formFieldErrors = [];
            if ($formData['fname'] === '') {
                $formFieldErrors['fname'][] = 'form.error.fname_required';
            }
            if ($formData['lname'] === '') {
                $formFieldErrors['lname'][] = 'form.error.lname_required';
            }
            if ($formData['email'] === '' || !filter_var($formData['email'], FILTER_VALIDATE_EMAIL)) {
                $formFieldErrors['email'][] = 'form.error.email_invalid';
            }
            if ($formData['message'] === '') {
                $formFieldErrors['message'][] = 'form.error.message_required';
            }
            if ($containsHeaderInjection($formData['email']) || $containsHeaderInjection($formData['fname'] . ' ' . $formData['lname'])) {
                $formErrors[] = 'form.error.header_injection';
            }

            $formTime = isset($_POST['form_time']) ? (int) $_POST['form_time'] : 0;
            if ($formTime > 0 && (time() - $formTime) < 3) {
                $formErrors[] = 'form.error.too_fast';
            }

            $lastSubmit = $_SESSION['last_contact_submit'] ?? 0;
            if ($lastSubmit && (time() - $lastSubmit) < 60) {
                $formErrors[] = 'form.error.rate_limit';
            }

            if (empty($formErrors) && empty($formFieldErrors)) {
                $interestKey = self::INTEREST_KEYS[$formData['interest']] ?? 'form.interest.visit';
                $interestLabel = I18n::t($interestKey, [], $locale);

                $to      = 'mki@kies-media.de';
                $subject = 'Kontaktanfrage: ' . $interestLabel;
                $body    = sprintf(
                    "Von: %s %s\nE-Mail: %s\n%sAnliegen: %s\n\n%s",
                    $formData['fname'],
                    $formData['lname'],
                    $formData['email'],
                    $formData['phone'] !== '' ? "Telefon: {$formData['phone']}\n" : '',
                    $interestLabel,
                    $formData['message']
                );

                $headers  = "From: {$formData['email']}\r\n";
                $headers .= "Reply-To: {$formData['email']}\r\n";
                $headers .= "Content-Type: text/plain; charset=UTF-8\r\n";
                $headers .= "X-Mailer: PHP/" . phpversion();

                if (mail($to, $subject, $body, $headers)) {
                    $_SESSION['last_contact_submit'] = time();
                    $_SESSION['form_success'] = true;
                    header('Location: /#kontakt');
                    exit;
                }

                $formErrors[] = 'form.error.send_failed';
            }

            $_SESSION['form_errors']      = $formErrors;
            $_SESSION['form_field_errors'] = $formFieldErrors;
            $_SESSION['form_data']         = $formData;
            header('Location: /#kontakt');
            exit;
        }

        // ── Structured data (JSON-LD) — localized ────────────────────
        $structuredData = json_encode([
            '@context'   => 'https://schema.org',
            '@type'      => 'RealEstateListing',
            'name'       => I18n::t('structured.listing_name', [], $locale),
            'description'=> I18n::t('structured.listing_description', [], $locale),
            'url'        => I18n::t('site.canonical_base', [], $locale) . '/',
            'image'      => I18n::t('site.canonical_base', [], $locale) . '/bilder/Außenansicht-2.png',
            'datePosted' => '2026-05-14',
            'address'    => [
                '@type'           => 'PostalAddress',
                'streetAddress'   => I18n::t('address.street', [], $locale),
                'addressLocality' => I18n::t('address.city', [], $locale),
                'postalCode'      => '98553',
                'addressCountry'  => 'DE',
            ],
            'offers' => [
                '@type'              => 'Offer',
                'price'              => '1300',
                'priceCurrency'      => 'EUR',
                'priceSpecification' => [
                    '@type'         => 'UnitPriceSpecification',
                    'price'         => '1300',
                    'priceCurrency' => 'EUR',
                    'unitCode'      => 'MON',
                    'description'   => I18n::t('structured.price_description', [], $locale),
                ],
            ],
            'floorSize' => [
                '@type'    => 'QuantitativeValue',
                'value'    => '227',
                'unitCode' => 'MTK',
            ],
            'numberOfRooms' => [
                '@type'  => 'QuantitativeValue',
                'value'  => '6',
            ],
        ], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

        $this->render('home/index', [
            'formSuccess'        => $formSuccess,
            'formErrors'         => $formErrors,
            'formFieldErrors'    => $formFieldErrors,
            'formData'           => $formData,
            'interestKeys'       => self::INTEREST_KEYS,
            'escapeContactValue' => $escapeContactValue,
            'structuredData'     => $structuredData,
        ]);
    }

    /**
     * @return array{fname: string, lname: string, email: string, phone: string, interest: string, message: string}
     */
    private static function emptyFormData(): array
    {
        return [
            'fname'    => '',
            'lname'    => '',
            'email'    => '',
            'phone'    => '',
            'interest' => 'visit',
            'message'  => '',
        ];
    }
}