import { NextResponse } from 'next/server';
import { mkdir, writeFile, rm } from 'node:fs/promises';
import path from 'node:path';
import crypto from 'node:crypto';
import { checkSystemBin } from '@/lib/system-bins';
import { restoreFromZipFile } from '@/lib/restore-zip';

export const dynamic = 'force-dynamic';
export const maxDuration = 600;

const PROJECT_ROOT = process.cwd();
const UPLOAD_STAGING = path.join(PROJECT_ROOT, '.restore-staging');

export async function POST(request: Request) {
  if (!(await checkSystemBin('unzip', '-v'))) {
    return NextResponse.json({ error: "Binario 'unzip' non disponibile sul server." }, { status: 503 });
  }

  const sessionId = crypto.randomUUID();
  const sessionDir = path.join(UPLOAD_STAGING, `upload-${sessionId}`);
  const zipPath = path.join(sessionDir, 'backup.zip');

  try {
    const formData = await request.formData();
    const file = formData.get('file') as File | null;
    if (!file) {
      return NextResponse.json({ error: 'Nessun file ricevuto.' }, { status: 400 });
    }

    await mkdir(sessionDir, { recursive: true });
    await writeFile(zipPath, Buffer.from(await file.arrayBuffer()));

    const result = await restoreFromZipFile(zipPath);
    if (!result.ok) {
      return NextResponse.json({ error: result.error, detail: result.detail }, { status: result.status });
    }
    return NextResponse.json({
      ok: true,
      restored: { cards: result.cards, portals: result.portals },
      previousDataBackup: result.previousBackup,
    });
  } catch (error) {
    console.error('Restore error:', error);
    return NextResponse.json({ error: 'Errore durante il ripristino.' }, { status: 500 });
  } finally {
    try { await rm(sessionDir, { recursive: true, force: true }); } catch { /* ignore */ }
  }
}