import { NextRequest, NextResponse } from "next/server";
import { prisma } from "@/lib/prisma";
import { loadFileData } from "@/lib/storage";

export async function GET(
  request: NextRequest,
  { params }: { params: { id: string } }
) {
  const file = await prisma.file.findUnique({ where: { id: params.id } });

  if (!file) {
    return NextResponse.json({ error: "File not found" }, { status: 404 });
  }

  // Contenu chiffré au repos → on déchiffre en mémoire puis on sert (avec support Range).
  const data = await loadFileData(file.storagePath, file.isEncrypted);
  const fileSize = data.length;

  const range = request.headers.get("range");

  if (range) {
    const parts = range.replace(/bytes=/, "").split("-");
    const start = parseInt(parts[0], 10);
    const end = parts[1]
      ? parseInt(parts[1], 10)
      : Math.min(start + 1024 * 1024 - 1, fileSize - 1);
    const chunk = data.subarray(start, end + 1);

    return new NextResponse(new Uint8Array(chunk), {
      status: 206,
      headers: {
        "Content-Range": `bytes ${start}-${end}/${fileSize}`,
        "Accept-Ranges": "bytes",
        "Content-Length": String(chunk.length),
        "Content-Type": file.mimeType,
        "Cache-Control": "private, max-age=3600",
      },
    });
  }

  return new NextResponse(new Uint8Array(data), {
    headers: {
      "Content-Length": String(fileSize),
      "Content-Type": file.mimeType,
      "Accept-Ranges": "bytes",
      "Cache-Control": "private, max-age=3600",
    },
  });
}