"use server";

import { writeFile, mkdir } from "fs/promises";
import path from "path";
import { getServerSession } from "next-auth";
import { authOptions } from "@/app/api/auth/[...nextauth]/route";

export async function uploadImage(formData: FormData): Promise<string> {
  const session = await getServerSession(authOptions);
  const adminIds = (process.env.ADMIN_DISCORD_IDS ?? "")
    .split(",")
    .map((s) => s.trim())
    .filter(Boolean);
  const discordId = (session?.user as { discordId?: string } | undefined)
    ?.discordId;
  if (!discordId || !adminIds.includes(discordId)) {
    throw new Error("Unauthorized");
  }

  const file = formData.get("file") as File;
  if (!file) throw new Error("No file provided");

  const ext = file.name.split(".").pop() ?? "png";
  const filename = `${crypto.randomUUID()}.${ext}`;
  const uploadDir = path.join(process.cwd(), "public", "form");

  await mkdir(uploadDir, { recursive: true });
  const buffer = Buffer.from(await file.arrayBuffer());
  await writeFile(path.join(uploadDir, filename), buffer);

  return `/form/${filename}`;
}