<?php

declare(strict_types=1);

use App\App\Bootstrap;
use App\Form\FormSchema;
use App\Security\Csrf;
use App\Security\FormAccess;
use App\Security\RateLimiter;
use App\Storage\FileUploadStore;
use App\Storage\JsonStore;

require dirname(__DIR__) . '/src/autoload.php';
Bootstrap::init();

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    Bootstrap::jsonResponse([
        'ok' => false,
        'message' => Bootstrap::appMessage('common.method_not_allowed'),
    ], 405);
}

$csrf = $_POST['csrf'] ?? '';
if (!Csrf::validate(is_string($csrf) ? $csrf : null)) {
    Bootstrap::jsonResponse([
        'ok' => false,
        'message' => Bootstrap::appMessage('common.invalid_csrf'),
    ], 419);
}

if (trim((string) ($_POST['website'] ?? '')) !== '') {
    Bootstrap::jsonResponse([
        'ok' => false,
        'message' => Bootstrap::appMessage('common.request_blocked'),
    ], 400);
}

$email = strtolower(trim((string) ($_POST['email'] ?? '')));
if (filter_var($email, FILTER_VALIDATE_EMAIL) === false) {
    Bootstrap::jsonResponse([
        'ok' => false,
        'message' => Bootstrap::appMessage('common.invalid_email'),
    ], 422);
}

$activityRaw = $_POST['last_user_activity_at'] ?? null;
$lastUserActivityAt = is_scalar($activityRaw) ? (int) $activityRaw : null;
$formAccess = new FormAccess();
$auth = $formAccess->assertVerifiedForEmail($email, $lastUserActivityAt);
if (($auth['ok'] ?? false) !== true) {
    $reason = (string) ($auth['reason'] ?? '');
    Bootstrap::jsonResponse([
        'ok' => false,
        'message' => (string) ($auth['message'] ?? 'Bitte E-Mail erneut verifizieren.'),
        'auth_required' => $reason === 'auth_required',
        'auth_expired' => $reason === 'auth_expired',
    ], (int) ($auth['status_code'] ?? 401));
}

$app = Bootstrap::config('app');
$limiter = new RateLimiter();
$ip = $_SERVER['REMOTE_ADDR'] ?? 'unknown';
$rateKey = sprintf('save:%s:%s', $ip, $email);
if (!$limiter->allow($rateKey, (int) $app['rate_limit']['requests'], (int) $app['rate_limit']['window_seconds'])) {
    Bootstrap::jsonResponse([
        'ok' => false,
        'message' => Bootstrap::appMessage('save_draft.rate_limited'),
    ], 429);
}

$step = (int) ($_POST['step'] ?? 1);
$formDataRaw = $_POST['form_data'] ?? [];
$formData = [];
if (is_array($formDataRaw)) {
    foreach ($formDataRaw as $key => $value) {
        if (!is_string($key)) {
            continue;
        }
        $formData[$key] = is_array($value) ? '' : trim((string) $value);
    }
}

$store = new JsonStore();

try {
    $result = $store->withEmailLock($email, static function () use ($store, $email, $step, $formData): array {
        if ($store->hasSubmission($email)) {
            return [
                'blocked' => true,
                'message' => Bootstrap::appMessage('save_draft.already_submitted'),
            ];
        }

        return [
            'blocked' => false,
            'draft' => $store->saveDraft($email, [
                'step' => max(1, $step),
                'form_data' => $formData,
                'uploads' => [],
            ]),
        ];
    });
} catch (Throwable $e) {
    Bootstrap::log('app', 'save-draft lock error: ' . $e->getMessage());
    Bootstrap::jsonResponse([
        'ok' => false,
        'message' => Bootstrap::appMessage('save_draft.lock_error'),
    ], 500);
}

if (($result['blocked'] ?? false) === true) {
    Bootstrap::jsonResponse([
        'ok' => false,
        'already_submitted' => true,
        'message' => (string) ($result['message'] ?? Bootstrap::appMessage('save_draft.blocked_fallback')),
    ], 409);
}

$schema = new FormSchema();
$uploadStore = new FileUploadStore();
$uploadResult = $uploadStore->processUploads($_FILES, $schema->getUploadFields(), $store->emailKey($email));

if (!empty($uploadResult['uploads'])) {
    try {
        $store->withEmailLock($email, static function () use ($store, $email, $step, $formData, $uploadResult): void {
            if ($store->hasSubmission($email)) {
                return;
            }

            $store->saveDraft($email, [
                'step' => max(1, $step),
                'form_data' => $formData,
                'uploads' => $uploadResult['uploads'],
            ]);
        });
    } catch (Throwable $e) {
        Bootstrap::log('app', 'save-draft upload merge error: ' . $e->getMessage());
    }
}

$draft = $store->getDraft($email);

Bootstrap::jsonResponse([
    'ok' => true,
    'message' => Bootstrap::appMessage('save_draft.success'),
    'updated_at' => $draft['updated_at'] ?? null,
    'upload_errors' => $uploadResult['errors'],
    'uploads' => $draft['uploads'] ?? [],
]);