Interview Prep Platform

from flask import Flask, request, jsonify
from flask_sqlalchemy import SQLAlchemy
from functools import wraps
import subprocess
import json

app = Flask(__name__)
db = SQLAlchemy(app)

class CodeSubmission(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
    problem_id = db.Column(db.Integer, db.ForeignKey('problem.id'))
    code = db.Column(db.Text)
    language = db.Column(db.String(50))
    status = db.Column(db.String(20))  # 'accepted', 'rejected', 'error'
    execution_time = db.Column(db.Float)
    memory_used = db.Column(db.Integer)

def execute_code(code, language, test_cases):
    """Execute user code against test cases with timeout"""
    results = []
    
    try:
        if language == 'python':
            cmd = ['python3', '-c', code]
        elif language == 'javascript':
            cmd = ['node', '-e', code]
        elif language == 'java':
            # Compile and run Java
            cmd = ['java', 'Solution']
        
        for test_case in test_cases:
            try:
                result = subprocess.run(
                    cmd,
                    input=test_case['input'],
                    capture_output=True,
                    timeout=5,
                    text=True
                )
                
                passed = result.stdout.strip() == test_case['expected_output'].strip()
                results.append({
                    'input': test_case['input'],
                    'expected': test_case['expected_output'],
                    'actual': result.stdout.strip(),
                    'passed': passed,
                    'error': result.stderr if result.returncode != 0 else None
                })
            except subprocess.TimeoutExpired:
                results.append({
                    'passed': False,
                    'error': 'Execution timeout (5s limit)'
                })
        
        return results
    except Exception as e:
        return {'error': str(e)}

@app.route('/api/submit', methods=['POST'])
def submit_code():
    """Handle code submission and validation"""
    data = request.json
    user_id = get_current_user()
    
    problem = Problem.query.get(data['problem_id'])
    results = execute_code(data['code'], data['language'], problem.test_cases)
    
    all_passed = all(r.get('passed', False) for r in results)
    
    submission = CodeSubmission(
        user_id=user_id,
        problem_id=data['problem_id'],
        code=data['code'],
        language=data['language'],
        status='accepted' if all_passed else 'rejected'
    )
    db.session.add(submission)
    db.session.commit()
    
    return jsonify({
        'submission_id': submission.id,
        'status': submission.status,
        'results': results,
        'all_passed': all_passed
    })

import React, { useState } from 'react';
import { Controlled as CodeMirror } from 'react-codemirror2';
import 'codemirror/lib/codemirror.css';
import 'codemirror/theme/dracula.css';
import 'codemirror/mode/python/python';

export function CodeEditor({ problemId, onSubmit }) {
  const [code, setCode] = useState('# Write your solution here\n');
  const [language, setLanguage] = useState('python');
  const [results, setResults] = useState(null);
  const [loading, setLoading] = useState(false);

  const handleSubmit = async () => {
    setLoading(true);
    try {
      const response = await fetch('/api/submit', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          problem_id: problemId,
          code,
          language
        })
      });
      
      const data = await response.json();
      setResults(data);
      onSubmit(data);
    } finally {
      setLoading(false);
    }
  };

  return (
    <div className="flex flex-col h-full bg-gray-900 text-white">
      <div className="flex gap-2 p-4 border-b border-gray-700">
        <select
          value={language}
          onChange={(e) => setLanguage(e.target.value)}
          className="bg-gray-800 text-white px-3 py-1 rounded"
        >
          <option value="python">Python</option>
          <option value="javascript">JavaScript</option>
          <option value="java">Java</option>
          <option value="cpp">C++</option>
        </select>
        
        <button
          onClick={handleSubmit}
          disabled={loading}
          className="ml-auto bg-blue-600 hover:bg-blue-700 px-4 py-1 rounded font-semibold"
        >
          {loading ? 'Running...' : 'Submit'}
        </button>
      </div>

      <div className="flex-1 overflow-hidden">
        <CodeMirror
          value={code}
          onBeforeChange={(editor, data, value) => setCode(value)}
          options={{
            mode: language,
            theme: 'dracula',
            lineNumbers: true,
            indentUnit: 2,
            tabSize: 2
          }}
        />
      </div>

      {results && (
        <div className="border-t border-gray-700 p-4 bg-gray-800 max-h-48 overflow-y-auto">
          <h3 className="font-bold mb-2">
            {results.all_passed ? '✅ All tests passed!' : '❌ Some tests failed'}
          </h3>
          {results.results.map((r, i) => (
            <div key={i} className={`mb-2 p-2 rounded ${r.passed ? 'bg-green-900' : 'bg-red-900'}`}>
              <div>Test {i + 1}: {r.passed ? 'PASS' : 'FAIL'}</div>
              {!r.passed && <div className="text-sm text-gray-300">Expected: {r.expected}</div>}
              {!r.passed && <div className="text-sm text-gray-300">Got: {r.actual}</div>}
            </div>
          ))}
        </div>
      )}
    </div>
  );
}