import { MAX_SHARE_BYTES, putShare, takeShare, type SharedFile } from "@/lib/share-inbox";

export const runtime = "nodejs";
export const dynamic = "force-dynamic";

function asString(value: FormDataEntryValue | null): string | undefined {
  return typeof value === "string" && value.trim() ? value.trim().slice(0, 20_000) : undefined;
}

/** GET /share?id=… — read (and consume) a payload that was POSTed in. */
export async function GET(request: Request) {
  const id = new URL(request.url).searchParams.get("id");
  if (!id) return Response.json({ error: "missing id" }, { status: 400 });
  const payload = takeShare(id);
  if (!payload) return Response.json({ error: "expired" }, { status: 404 });
  return Response.json(payload);
}

/**
 * POST /share — the Web Share Target. Text/URL arrive as form fields, files
 * as multipart uploads; both are stashed briefly and the browser is redirected
 * to the chooser page with an opaque id.
 */
export async function POST(request: Request) {
  let form: FormData;
  try {
    form = await request.formData();
  } catch {
    return Response.redirect(new URL("/share?error=bad", request.url), 303);
  }

  const uploads = form.getAll("files").filter((entry): entry is File => entry instanceof File);
  const total = uploads.reduce((sum, file) => sum + file.size, 0);
  if (total > MAX_SHARE_BYTES) {
    return Response.redirect(new URL("/share?error=large", request.url), 303);
  }
  const files: SharedFile[] = [];
  for (const file of uploads.slice(0, 6)) {
    files.push({
      name: file.name || "shared",
      type: file.type || "application/octet-stream",
      data: Buffer.from(await file.arrayBuffer()).toString("base64"),
    });
  }

  const id = crypto.randomUUID();
  putShare(id, {
    title: asString(form.get("title")),
    text: asString(form.get("text")),
    url: asString(form.get("url")),
    files,
  });

  return Response.redirect(new URL(`/share?id=${id}`, request.url), 303);
}