import { existsSync, readdirSync, statSync, readFileSync } from "fs";
import { join } from "path";

const DB_DIR = join(process.cwd(), "data");
const DB_PATH = join(DB_DIR, "nexova.db");

export async function POST(req: Request) {
  const { action } = await req.json().catch(() => ({ action: "backup" }));

  if (action === "info") {
    const files = existsSync(DB_DIR)
      ? readdirSync(DB_DIR).map((f) => {
          const s = statSync(join(DB_DIR, f));
          return { name: f, size: `${(s.size / 1024).toFixed(1)}KB`, modified: s.mtime.toISOString() };
        })
      : [];
    return Response.json({ ok: true, data: { dir: DB_DIR, files } });
  }

  if (action === "backup") {
    if (!existsSync(DB_PATH))
      return Response.json({ ok: false, error: "no database file" }, { status: 400 });
    const token = process.env.HF_TOKEN;
    const repo = process.env.HF_DATASET ?? "jay-hank/Nexova-storage";
    if (!token) return Response.json({ ok: false, error: "HF_TOKEN not set" }, { status: 500 });

    try {
      const file = readFileSync(DB_PATH);
      const b64 = Buffer.from(file).toString("base64");

      const res = await fetch(
        `https://huggingface.co/api/datasets/${repo}/commit/main`,
        {
          method: "POST",
          headers: {
            Authorization: `Bearer ${token}`,
            "Content-Type": "application/json",
          },
          body: JSON.stringify({
            summary: `backup ${new Date().toISOString()}`,
            operations: [{
              op: "upload",
              path: "nexova.db",
              encoding: "base64",
              content: b64,
            }],
          }),
        }
      );
      const status = res.status;
      const text = await res.text();
      return Response.json({ ok: status < 400, message: `HTTP ${status}`, detail: text });
    } catch (e: unknown) {
      return Response.json({ ok: false, error: e instanceof Error ? e.message : String(e) }, { status: 500 });
    }
  }

  return Response.json({ ok: false, error: `unknown action: ${action}` }, { status: 400 });
}