<?php

declare(strict_types=1);

// POST api/v1/backup.php
// Receives a backup archive from an authenticated instance.
//
// multipart/form-data fields:
//   filename  backup-YYYYmmdd-HHMMSS[-N].zip
//   sha256    client-side checksum, re-verified here
//   meta      optional JSON (trigger, file_count, source_bytes, app_version)
//   backup    the ZIP file itself

require_once __DIR__ . "/../../includes/api.php";
require_once __DIR__ . "/../../includes/backups.php";

manageApiRequireMethod("POST");
$instance = manageApiAuthenticate();

try {
    $file = $_FILES["backup"] ?? null;
    if (!is_array($file)) {
        throw new RuntimeException("Backup-Datei fehlt.");
    }

    $uploadError = (int) ($file["error"] ?? UPLOAD_ERR_NO_FILE);
    if ($uploadError !== UPLOAD_ERR_OK) {
        // INI_SIZE / FORM_SIZE are the common real-world failure and deserve a
        // message that names the cause instead of a bare error code.
        if ($uploadError === UPLOAD_ERR_INI_SIZE || $uploadError === UPLOAD_ERR_FORM_SIZE) {
            throw new RuntimeException(
                "Backup überschreitet das Upload-Limit des Servers (upload_max_filesize / post_max_size).",
            );
        }
        throw new RuntimeException("Upload fehlgeschlagen (Fehlercode " . $uploadError . ").");
    }

    $tmpName = (string) ($file["tmp_name"] ?? "");
    if ($tmpName === "" || !is_uploaded_file($tmpName)) {
        throw new RuntimeException("Upload ist ungültig.");
    }

    $maxBytes = (int) MANAGE_BACKUP_MAX_UPLOAD_BYTES;
    if ($maxBytes > 0 && (int) ($file["size"] ?? 0) > $maxBytes) {
        throw new RuntimeException("Backup überschreitet die konfigurierte Maximalgröße.");
    }

    if (!manageFileIsZip($tmpName)) {
        throw new RuntimeException("Die hochgeladene Datei muss ein ZIP-Archiv sein.");
    }

    $meta = [];
    $rawMeta = trim((string) ($_POST["meta"] ?? ""));
    if ($rawMeta !== "") {
        $decoded = json_decode($rawMeta, true);
        if (is_array($decoded)) {
            $meta = $decoded;
        }
    }

    $result = manageBackupStoreUpload(
        $instance["id"],
        $tmpName,
        (string) ($_POST["filename"] ?? ""),
        (string) ($_POST["sha256"] ?? ""),
        $meta,
    );

    manageApiSendJson(200, array_merge(["success" => true, "instance" => $instance["id"]], $result));
} catch (Throwable $exception) {
    manageLogError("Backup upload rejected", [
        "instance" => $instance["id"],
        "error" => $exception->getMessage(),
    ]);
    manageApiFail(400, $exception->getMessage());
}