import { NextResponse } from 'next/server';
import path from 'node:path';
import fs from 'node:fs/promises';

const BASE_DIR = '/app/files';

export async function GET(req: Request) {
  try {
    const url = new URL(req.url);
    const raw = url.searchParams.get('path') ?? '/';
    const safe = path.normalize('/' + raw).replace(/^\/+/, '/'); // normalize & ensure leading slash
    const target = path.resolve(BASE_DIR, '.' + safe);

    if (!target.startsWith(BASE_DIR)) {
      return NextResponse.json({ error: 'Invalid path' }, { status: 400 });
    }

    const st = await fs.stat(target).catch(() => null);
    if (!st || !st.isDirectory()) {
      return NextResponse.json({ error: 'Not a directory' }, { status: 400 });
    }

    const entries = await fs.readdir(target, { withFileTypes: true });
    const items = await Promise.all(entries.map(async (d) => {
      const full = path.join(target, d.name);
      const rel = path.posix.join(safe, d.name).replaceAll('\\', '/');
      const s = await fs.stat(full);
      return {
        name: d.name,
        path: rel,
        type: d.isDirectory() ? 'dir' : 'file',
        size: s.size,
        mtime: s.mtimeMs,
      };
    }));

    return NextResponse.json({ path: safe, items });
  } catch (e: any) {
    return NextResponse.json({ error: e?.message ?? 'Unknown error' }, { status: 500 });
  }
}