// Mobile menu toggle
document.addEventListener('DOMContentLoaded', function() {
  const toggle = document.querySelector('.menu-toggle');
  const navList = document.querySelector('.nav-list');

  if (toggle) {
    toggle.addEventListener('click', function() {
      navList.classList.toggle('open');
    });
  }

  // Close menu on link click
  const navLinks = document.querySelectorAll('.nav-list a');
  navLinks.forEach(function(link) {
    link.addEventListener('click', function() {
      if (navList) navList.classList.remove('open');
    });
  });

  // Highlight active page in nav
  const currentPage = window.location.pathname.split('/').pop() || 'index.html';
  navLinks.forEach(function(link) {
    const href = link.getAttribute('href');
    if (href === currentPage) {
      link.classList.add('active');
    }
  });
});

// --- Exercises ---
function checkExercise(btn) {
  const exercise = btn.closest('.exercise');
  const selected = exercise.querySelector('input[type="radio"]:checked');
  const feedback = exercise.querySelector('.feedback');

  if (!selected) {
    feedback.textContent = 'Please select an answer!';
    feedback.className = 'feedback wrong';
    feedback.style.display = 'block';
    return;
  }

  const options = exercise.querySelectorAll('.option');
  options.forEach(function(opt) {
    opt.classList.remove('correct', 'wrong');
  });

  const parent = selected.closest('.option');
  const isCorrect = selected.value === 'true';

  if (isCorrect) {
    parent.classList.add('correct');
    feedback.textContent = 'Correct!';
    feedback.className = 'feedback correct';
  } else {
    parent.classList.add('wrong');
    feedback.textContent = 'Try again!';
    feedback.className = 'feedback wrong';
    // Show correct answer
    options.forEach(function(opt) {
      const radio = opt.querySelector('input[type="radio"]');
      if (radio && radio.value === 'true') {
        opt.classList.add('correct');
      }
    });
  }
  feedback.style.display = 'block';
}

function checkFill(input) {
  const exercise = input.closest('.exercise');
  const answer = input.getAttribute('data-answer');
  const feedback = exercise.querySelector('.feedback');

  input.classList.remove('correct', 'wrong');

  if (input.value.trim().toLowerCase() === answer.toLowerCase()) {
    input.classList.add('correct');
    feedback.textContent = 'Correct!';
    feedback.className = 'feedback correct';
  } else {
    input.classList.add('wrong');
    feedback.textContent = 'Try again! Correct answer: ' + answer;
    feedback.className = 'feedback wrong';
  }
  feedback.style.display = 'block';
}

function checkTranslate(btn) {
  const exercise = btn.closest('.exercise');
  const input = exercise.querySelector('input[type="text"]');
  const feedback = exercise.querySelector('.feedback');
  const answer = input.getAttribute('data-answer');

  input.classList.remove('correct', 'wrong');

  if (input.value.trim().toLowerCase() === answer.toLowerCase()) {
    input.classList.add('correct');
    feedback.textContent = 'Correct!';
    feedback.className = 'feedback correct';
  } else {
    input.classList.add('wrong');
    feedback.textContent = 'Try again! Correct answer: ' + answer;
    feedback.className = 'feedback wrong';
  }
  feedback.style.display = 'block';
}

function checkMatch(btn) {
  const exercise = btn.closest('.exercise');
  const inputs = exercise.querySelectorAll('input[type="text"]');
  const feedback = exercise.querySelector('.feedback');
  let allCorrect = true;

  inputs.forEach(function(input) {
    const answer = input.getAttribute('data-answer');
    input.classList.remove('correct', 'wrong');
    if (input.value.trim().toLowerCase() === answer.toLowerCase()) {
      input.classList.add('correct');
    } else {
      input.classList.add('wrong');
      allCorrect = false;
    }
  });

  if (allCorrect) {
    feedback.textContent = 'All correct! Great job!';
    feedback.className = 'feedback correct';
  } else {
    feedback.textContent = 'Some answers are wrong. Try again!';
    feedback.className = 'feedback wrong';
  }
  feedback.style.display = 'block';
}

// --- Tests ---
function checkTest() {
  let score = 0;
  const total = document.querySelectorAll('.test-question').length;
  const questions = document.querySelectorAll('.test-question');

  questions.forEach(function(q) {
    const selected = q.querySelector('input[type="radio"]:checked');
    if (selected && selected.value === 'true') {
      score++;
    }
  });

  const resultBox = document.getElementById('test-result');
  const scoreDisplay = document.getElementById('score');
  scoreDisplay.textContent = score + '/' + total;
  resultBox.classList.add('show');

  // Scroll to result
  resultBox.scrollIntoView({ behavior: 'smooth' });
}

// --- Contact form ---
function submitForm(event) {
  event.preventDefault();
  const message = document.getElementById('form-message');
  message.classList.add('show');
  document.getElementById('contact-form').reset();
  setTimeout(function() {
    message.classList.remove('show');
  }, 5000);
}

// --- Pronunciation ---
function speakWord(word, rate) {
  if (!window.speechSynthesis) {
    alert('Speech synthesis is not supported in your browser.');
    return;
  }
  window.speechSynthesis.cancel();
  var utterance = new SpeechSynthesisUtterance(word);
  utterance.lang = 'en-US';
  utterance.rate = rate || 0.9;
  utterance.pitch = 1;
  window.speechSynthesis.speak(utterance);
}

function repeatWord(btn) {
  var word = btn.getAttribute('data-word');
  speakWord(word, 0.8);
  btn.textContent = '🔊 Playing...';
  setTimeout(function() { btn.textContent = '🔊 Listen'; }, 1500);
}

function speakSlow(btn) {
  var word = btn.getAttribute('data-word');
  speakWord(word, 0.4);
  btn.textContent = '🐢 Slow...';
  setTimeout(function() { btn.innerHTML = '🐢 Slow'; }, 2000);
}

function checkDictation(input) {
  var exercise = input.closest('.exercise');
  var answer = input.getAttribute('data-answer');
  var feedback = exercise.querySelector('.feedback');

  input.classList.remove('correct', 'wrong');

  if (input.value.trim().toLowerCase() === answer.toLowerCase()) {
    input.classList.add('correct');
    feedback.textContent = 'Correct! Great listening!';
    feedback.className = 'feedback correct';
  } else {
    input.classList.add('wrong');
    feedback.textContent = 'Not quite. The correct word is: ' + answer;
    feedback.className = 'feedback wrong';
  }
  feedback.style.display = 'block';
}

function speakPhrase(btn) {
  var phrase = btn.getAttribute('data-phrase');
  speakWord(phrase, 0.8);
  btn.textContent = '🔊 Playing...';
  setTimeout(function() { btn.innerHTML = '🔊 Hear Phrase'; }, 1500);
}

// --- Vocabulary filter ---
function filterVocab(category, btn) {
  const rows = document.querySelectorAll('.vocab-row');
  const buttons = document.querySelectorAll('.category-btn');

  buttons.forEach(function(b) { b.classList.remove('active'); });
  if (btn) btn.classList.add('active');

  rows.forEach(function(row) {
    if (category === 'all' || row.getAttribute('data-category') === category) {
      row.style.display = '';
    } else {
      row.style.display = 'none';
    }
  });
}