<?php
/**
 * POST /api/artifact
 * Multipart-Upload für Modul-erzeugte Artefakte (Bilder, Karten, Audio).
 */

declare(strict_types=1);
require_once __DIR__ . '/../../bootstrap.php';

v2_validate_method('POST');
$auth = v2_auth_require('student');
$studentId = (int) ($auth['sub'] ?? 0);

$slug = $_POST['moduleSlug'] ?? '';
$label = $_POST['label'] ?? '';
if (!$slug) {
    v2_response_error(400, 'missing_slug', 'Feld "moduleSlug" fehlt.');
}

if (empty($_FILES['file']) || $_FILES['file']['error'] !== UPLOAD_ERR_OK) {
    v2_response_error(400, 'upload_failed', 'Datei-Upload fehlgeschlagen.');
}

$file = $_FILES['file'];
$mimeType = mime_content_type($file['tmp_name']) ?: 'application/octet-stream';

// Erlaubte MIME-Typen
$allowedMime = ['image/png', 'image/jpeg', 'image/webp', 'audio/mpeg', 'audio/wav', 'audio/ogg', 'application/pdf'];
if (!in_array($mimeType, $allowedMime, true)) {
    v2_response_error(415, 'unsupported_media_type', "MIME-Typ '$mimeType' nicht erlaubt.");
}

// Max 10 MB
if ($file['size'] > 10 * 1024 * 1024) {
    v2_response_error(413, 'file_too_large', 'Max 10 MB pro Upload.');
}

// Ablage
$uploadDir = V2_ROOT . "/uploads/$slug/student-$studentId";
if (!is_dir($uploadDir)) {
    if (!mkdir($uploadDir, 0775, true)) {
        v2_response_error(500, 'upload_dir_failed', 'Upload-Ordner konnte nicht erstellt werden.');
    }
}

$ext = pathinfo($file['name'], PATHINFO_EXTENSION) ?: 'bin';
$ext = preg_replace('/[^a-zA-Z0-9]/', '', $ext);
$filename = sprintf('%s-%s.%s', date('Ymd-His'), bin2hex(random_bytes(4)), $ext);
$destPath = "$uploadDir/$filename";
$publicUrl = V2_BASE_URL . "/uploads/$slug/student-$studentId/$filename";

if (!move_uploaded_file($file['tmp_name'], $destPath)) {
    v2_response_error(500, 'move_failed', 'Datei konnte nicht abgelegt werden.');
}

v2_db_exec("
    INSERT INTO artifacts_v2
        (student_id, module_slug, mime_type, url, label, bytes)
    VALUES
        (:sid, :slug, :mt, :url, :lbl, :b)
", [
    ':sid' => $studentId,
    ':slug' => $slug,
    ':mt' => $mimeType,
    ':url' => $publicUrl,
    ':lbl' => $label,
    ':b' => (int) $file['size'],
]);
$id = (int) v2_db_insert_id();

v2_response_created([
    'id' => $id,
    'url' => $publicUrl,
    'thumbnail' => null,  // TODO: Thumbnail-Generation für Bilder
]);