'use server';

import { uploadBuffer } from '@/lib/ftps';

const MIME_EXT: Record<string, string> = {
  'image/png': '.png',
  'image/jpeg': '.jpg',
  'image/webp': '.webp',
};

export interface UploadResult {
  ok: boolean;
  url?: string;
  error?: string;
}

/**
 * Receives a captured result image and uploads it to the customer FTPS server.
 * Invoked from the client (ResultStep) via an event handler, not a form.
 *
 * Runs on the Node.js runtime (standalone server) — required by `basic-ftp`.
 */
export async function uploadResultImage(
  formData: FormData,
): Promise<UploadResult> {
  try {
    const image = formData.get('image');
    if (!(image instanceof File)) {
      return { ok: false, error: 'missing image' };
    }

    const ext = MIME_EXT[image.type] ?? '.png';
    const buffer = Buffer.from(await image.arrayBuffer());
    const url = await uploadBuffer(buffer, ext);

    // TODO: HEAD-verify the public URL is reachable before returning, so the QR
    // never points at a not-yet-served file (architecture.md §5.1).

    return { ok: true, url };
  } catch (err) {
    return {
      ok: false,
      error: err instanceof Error ? err.message : 'upload failed',
    };
  }
}