professor/app/api/execute/route.ts

import { NextRequest, NextResponse } from 'next/server';
import { executePython } from '@/lib/pistonClient';
import type { ExecuteRequestBody } from '@/types';

const MAX_CODE_LENGTH = 10_000;

export async function POST(req: NextRequest) {
  let body: ExecuteRequestBody;

  try {
    body = await req.json();
  } catch {
    return NextResponse.json({ error: 'Invalid JSON' }, { status: 400 });
  }

  const { language, code, stdin } = body;

  if (!language || !code) {
    return NextResponse.json({ error: 'Missing language or code' }, { status: 400 });
  }

  if (code.length > MAX_CODE_LENGTH) {
    return NextResponse.json({ error: 'Code exceeds maximum length of 10,000 characters' }, { status: 400 });
  }

  // HTML is rendered client-side via iframe — no backend execution needed
  if (language === 'html') {
    return NextResponse.json({
      stdout: '',
      stderr: '',
      exitCode: 0,
      timedOut: false,
    });
  }

  const result = await executePython(code, stdin ?? '');
  return NextResponse.json(result);
}