// ============================================================
// APP.JS - Core utilities and tab navigation
// ============================================================

// --- TAB NAVIGATION ---
document.querySelectorAll('.tab-btn').forEach(function(btn) {
  btn.addEventListener('click', function() {
    document.querySelectorAll('.tab-btn').forEach(function(b) { b.classList.remove('active'); });
    document.querySelectorAll('.tab-content').forEach(function(c) { c.classList.remove('active'); });
    btn.classList.add('active');
    var tabId = btn.getAttribute('data-tab') + '-tab';
    document.getElementById(tabId).classList.add('active');
  });
});

// --- MODEL SELECTOR ---
var modelSelect = document.getElementById('global-model-select');
var costBadge = document.getElementById('model-cost-badge');
var MODEL_COSTS = {
  'google/gemini-2.5-flash': '~$0.001/call',
  'google/gemini-2.5-flash:thinking': '~$0.002/call',
  'deepseek/deepseek-chat-v3-0324': '~$0.001/call',
  'deepseek/deepseek-r1:free': 'FREE ✨',
  'qwen/qwen3-30b-a3b:free': 'FREE ✨',
  'meta-llama/llama-3.1-70b-instruct': '~$0.001/call',
  'openai/gpt-4o': '~$0.01/call',
  'anthropic/claude-sonnet-4': '~$0.015/call'
};

function getSelectedModel() {
  return modelSelect ? modelSelect.value : 'google/gemini-2.5-flash';
}

if (modelSelect) {
  modelSelect.addEventListener('change', function() {
    var m = modelSelect.value;
    if (costBadge) {
      costBadge.textContent = MODEL_COSTS[m] || '~$0.001/call';
    }
    showToast('Model: ' + m.split('/').pop(), 'info');
  });
}

// --- LOADING ---
function showLoading(text) {
  document.getElementById('loading-text').textContent = text || 'Processing...';
  document.getElementById('loading-overlay').classList.remove('hidden');
}
function hideLoading() {
  document.getElementById('loading-overlay').classList.add('hidden');
}

// --- TOAST ---
function showToast(message, type) {
  var container = document.getElementById('toast-container');
  var toast = document.createElement('div');
  toast.className = 'toast toast-' + (type || 'success');
  var icon = type === 'error' ? 'exclamation-circle' : type === 'info' ? 'info-circle' : 'check-circle';
  toast.innerHTML = '<i class="fas fa-' + icon + '"></i> ' + message;
  container.appendChild(toast);
  setTimeout(function() { toast.remove(); }, 3000);
}

// --- COPY ---
function copyText(elementId) {
  var el = document.getElementById(elementId);
  var text = el.innerText || el.textContent;
  navigator.clipboard.writeText(text).then(function() {
    showToast('Copied to clipboard!', 'success');
  }).catch(function() {
    // Fallback
    var range = document.createRange();
    range.selectNode(el);
    window.getSelection().removeAllRanges();
    window.getSelection().addRange(range);
    document.execCommand('copy');
    window.getSelection().removeAllRanges();
    showToast('Copied!', 'success');
  });
}

// ============================================================
// SPEAK / STOP READING
// ============================================================
var currentlyReadingId = null;
var currentAudio = null;

function speakText(elementId) {
  // If already reading THIS element, stop it
  if (currentlyReadingId === elementId) {
    stopReading();
    return;
  }

  // Stop any previous reading first
  stopReading();

  var el = document.getElementById(elementId);
  var text = (el.innerText || el.textContent).trim();

  if (!text) {
    showToast('Nothing to read', 'error');
    return;
  }

  // Find the read button that triggered this
  var readBtn = findReadButton(elementId);

  // Try ElevenLabs first
  fetch('/api/text-to-speech', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ text: text.substring(0, 5000) })
  })
  .then(function(response) {
    if (!response.ok) throw new Error('ElevenLabs not available');
    return response.blob();
  })
  .then(function(blob) {
    var url = URL.createObjectURL(blob);
    currentAudio = new Audio(url);
    currentlyReadingId = elementId;

    setReadButtonActive(readBtn, true);

    currentAudio.onended = function() {
      stopReading();
    };

    currentAudio.onerror = function() {
      stopReading();
      // Fall back to browser TTS
      useBrowserTTS(text, elementId, readBtn);
    };

    currentAudio.play();
    showToast('Playing audio — click Stop to end', 'info');
  })
  .catch(function() {
    // Fall back to browser speech
    useBrowserTTS(text, elementId, readBtn);
  });
}

function useBrowserTTS(text, elementId, readBtn) {
  if (!('speechSynthesis' in window)) {
    showToast('Text-to-speech not supported', 'error');
    return;
  }

  window.speechSynthesis.cancel();

  var utterance = new SpeechSynthesisUtterance(text);
  utterance.rate = 0.9;
  utterance.pitch = 1.0;

  utterance.onend = function() {
    stopReading();
  };

  utterance.onerror = function() {
    stopReading();
  };

  currentlyReadingId = elementId;
  setReadButtonActive(readBtn, true);

  window.speechSynthesis.speak(utterance);
  showToast('Reading aloud — click Stop to end', 'info');
}

function stopReading() {
  // Stop browser TTS
  if ('speechSynthesis' in window) {
    window.speechSynthesis.cancel();
  }

  // Stop ElevenLabs audio
  if (currentAudio) {
    currentAudio.pause();
    currentAudio.currentTime = 0;
    if (currentAudio.src && currentAudio.src.startsWith('blob:')) {
      URL.revokeObjectURL(currentAudio.src);
    }
    currentAudio = null;
  }

  // Reset button state
  if (currentlyReadingId) {
    var readBtn = findReadButton(currentlyReadingId);
    setReadButtonActive(readBtn, false);
    currentlyReadingId = null;
  }
}

function findReadButton(elementId) {
  // Walk up from the output text to find the read button in the same card
  var el = document.getElementById(elementId);
  if (!el) return null;
  var card = el.closest('.output-card') || el.closest('.card');
  if (!card) return null;
  // Find the button that calls speakText with this elementId
  var buttons = card.querySelectorAll('button');
  for (var i = 0; i < buttons.length; i++) {
    var onclick = buttons[i].getAttribute('onclick') || '';
    if (onclick.indexOf('speakText') !== -1 && onclick.indexOf(elementId) !== -1) {
      return buttons[i];
    }
  }
  return null;
}

function setReadButtonActive(btn, isActive) {
  if (!btn) return;

  if (isActive) {
    btn.classList.add('btn-reading');
    btn.innerHTML = '<i class="fas fa-stop"></i> Stop';
  } else {
    btn.classList.remove('btn-reading');
    btn.innerHTML = '<i class="fas fa-volume-up"></i> Read';
  }
}

// --- TIMER ---
function createTimer(displayEl) {
  var secs = 0;
  var interval = null;
  return {
    start: function() {
      secs = 0;
      this.update();
      var self = this;
      interval = setInterval(function() { secs++; self.update(); }, 1000);
    },
    stop: function() {
      if (interval) { clearInterval(interval); interval = null; }
      return secs;
    },
    update: function() {
      var m = String(Math.floor(secs / 60)).padStart(2, '0');
      var s = String(secs % 60).padStart(2, '0');
      displayEl.textContent = m + ':' + s;
    }
  };
}

// --- AUDIO RECORDER ---
function AudioRecorder() {
  this.mediaRecorder = null;
  this.chunks = [];
  this.stream = null;
}

AudioRecorder.prototype.start = function() {
  var self = this;
  self.chunks = [];
  return navigator.mediaDevices.getUserMedia({
    audio: { channelCount: 1, echoCancellation: true, noiseSuppression: true }
  }).then(function(stream) {
    self.stream = stream;
    var mimeType = 'audio/webm';
    if (MediaRecorder.isTypeSupported('audio/webm;codecs=opus')) {
      mimeType = 'audio/webm;codecs=opus';
    }
    self.mediaRecorder = new MediaRecorder(stream, { mimeType: mimeType });
    self.mediaRecorder.ondataavailable = function(e) {
      if (e.data.size > 0) self.chunks.push(e.data);
    };
    self.mediaRecorder.start(1000);
  });
};

AudioRecorder.prototype.stop = function() {
  var self = this;
  return new Promise(function(resolve) {
    if (!self.mediaRecorder || self.mediaRecorder.state === 'inactive') {
      resolve(null);
      return;
    }
    self.mediaRecorder.onstop = function() {
      var blob = new Blob(self.chunks, { type: self.mediaRecorder.mimeType });
      if (self.stream) {
        self.stream.getTracks().forEach(function(t) { t.stop(); });
      }
      resolve(blob);
    };
    self.mediaRecorder.stop();
  });
};

console.log('✅ App.js loaded');