import { NextRequest, NextResponse } from "next/server";
import { getSession } from "@/lib/session";
import { writeFile, mkdir } from "fs/promises";
import path from "path";
import { sanitizeFilename } from "@/lib/upload";

function getUploadDirFar(root: string) {
  const dir = process.env.UPLOAD_DIR || path.join(process.cwd(), "public", "uploads");
  return path.join(dir, root.replace(/^\//, ""));
}

export async function POST(req: NextRequest) {
  const session = await getSession();
  if (!session) {
    return NextResponse.json({ error: "Non autorisé" }, { status: 401 });
  }

  try {
    const formData = await req.formData();
    const file = formData.get("file") as File | null;
    const subdirRaw = (formData.get("subdir") as string) || "";
    const subdir = subdirRaw.replace(/[^a-zA-Z0-9_/-]/g, "");

    if (!file) {
      return NextResponse.json({ error: "Aucun fichier fourni" }, { status: 400 });
    }

    const originalName = sanitizeFilename(file.name);
    const timestamp = Date.now();
    const ext = path.extname(originalName) || ".bin";
    const base = path.basename(originalName, ext);
    const filename = `${timestamp}-${base}${ext}`;

    const targetDir = getUploadDirFar(subdir);
    await mkdir(targetDir, { recursive: true });

    const bytes = Buffer.from(await file.arrayBuffer());
    await writeFile(path.join(targetDir, filename), bytes);

    const publicPath = `/uploads${subdir ? "/" + subdir : ""}/${filename}`;

    return NextResponse.json({ url: publicPath, filename }, { status: 200 });
  } catch (error) {
    console.error("Upload error:", error);
    return NextResponse.json({ error: "Erreur lors de l'upload" }, { status: 500 });
  }
}