// State
let currentSlideIndex = 0;
let presentationSlides = [];

// Demo presentation data
const demoSlides = [
  {
    title: "AI Video Analytics — B2B Product",
    bullets: ["Transforming video data into actionable business insights", "Powered by advanced computer vision and machine learning", "Built for enterprise-scale deployments"]
  },
  {
    title: "Business Problem",
    bullets: ["Organizations generate 1000s of hours of video footage daily", "Manual review is time-consuming and error-prone", "Critical insights remain hidden in unstructured data", "Security and operational teams lack real-time visibility"]
  },
  {
    title: "Our Solution",
    bullets: ["AI-powered video analytics platform", "Real-time object detection and behavior analysis", "Automated alerting and reporting", "Seamless integration with existing camera infrastructure"]
  },
  {
    title: "How It Works",
    bullets: ["Connect existing IP cameras to our platform", "AI models process video streams in real-time", "Detect anomalies, track objects, recognize patterns", "Dashboard provides instant insights and alerts"]
  },
  {
    title: "Business Benefits",
    bullets: ["Reduce manual monitoring costs by 70%", "Faster incident response time (from hours to seconds)", "Data-driven decision making", "Scalable from 10 to 10,000+ cameras"]
  },
  {
    title: "Next Steps",
    bullets: ["Schedule a live demo of the platform", "Discuss your specific use cases", "Pilot program: 30-day free trial", "ROI analysis for your organization"]
  }
];

// Navigation
function navigateTo(page) {
  document.querySelectorAll('.page').forEach(p => p.classList.remove('active'));
  document.querySelectorAll('.nav-link').forEach(l => l.classList.remove('active'));
  
  document.getElementById('page-' + page).classList.add('active');
  const navLink = document.querySelector('.nav-link[data-page="' + page + '"]');
  if (navLink) navLink.classList.add('active');
  
  window.scrollTo(0, 0);
}

// Form submission
document.getElementById('create-form').addEventListener('submit', function(e) {
  e.preventDefault();
  
  const topic = document.getElementById('topic').value;
  const audience = document.querySelector('input[name="audience"]:checked').value;
  const style = document.querySelector('input[name="style"]:checked').value;
  const slides = document.querySelector('input[name="slides"]:checked').value;
  
  // Show loading
  document.getElementById('loading').classList.add('active');
  
  // Simulate AI generation (2 seconds)
  setTimeout(function() {
    document.getElementById('loading').classList.remove('active');
    
    // Use demo slides (in real app, this would be AI-generated)
    presentationSlides = demoSlides.slice(0, Math.min(slides, demoSlides.length));
    currentSlideIndex = 0;
    
    // Navigate to editor
    navigateTo('editor');
    renderEditor();
  }, 1500);
});

// Render editor
function renderEditor() {
  renderThumbnails();
  renderSlidePreview();
  updateSlideCounter();
}

// Render thumbnails
function renderThumbnails() {
  const container = document.getElementById('slide-thumbnails');
  container.innerHTML = presentationSlides.map(function(slide, index) {
    return '<div class="thumbnail' + (index === currentSlideIndex ? ' active' : '') + '" onclick="goToSlide(' + index + ')">' +
      '<div class="thumbnail-number">Slide ' + (index + 1) + '</div>' +
      '<div class="thumbnail-title">' + escapeHtml(slide.title) + '</div>' +
    '</div>';
  }).join('');
}

// Render slide preview
function renderSlidePreview() {
  const container = document.getElementById('slide-preview');
  const slide = presentationSlides[currentSlideIndex];
  
  container.innerHTML = '<div class="slide-content">' +
    '<h2>' + escapeHtml(slide.title) + '</h2>' +
    '<ul>' + slide.bullets.map(function(bullet) {
      return '<li>' + escapeHtml(bullet) + '</li>';
    }).join('') + '</ul>' +
  '</div>';
}

// Update counter
function updateSlideCounter() {
  document.getElementById('slide-counter').textContent = (currentSlideIndex + 1) + ' / ' + presentationSlides.length;
}

// Navigation
function goToSlide(index) {
  if (index >= 0 && index < presentationSlides.length) {
    currentSlideIndex = index;
    renderThumbnails();
    renderSlidePreview();
    updateSlideCounter();
  }
}

function prevSlide() {
  goToSlide(currentSlideIndex - 1);
}

function nextSlide() {
  goToSlide(currentSlideIndex + 1);
}

// Editor actions
function editSlide() {
  const slide = presentationSlides[currentSlideIndex];
  const newTitle = prompt('Edit slide title:', slide.title);
  if (newTitle && newTitle.trim()) {
    slide.title = newTitle.trim();
    renderEditor();
  }
}

function regenerateSlide() {
  // Simulate regeneration
  const loading = document.getElementById('loading');
  loading.classList.add('active');
  loading.querySelector('p').textContent = 'Regenerating slide...';
  
  setTimeout(function() {
    loading.classList.remove('active');
    loading.querySelector('p').textContent = 'Generating your presentation...';
    
    // For demo, just shuffle bullets slightly
    const slide = presentationSlides[currentSlideIndex];
    if (slide.bullets.length > 1) {
      const temp = slide.bullets[0];
      slide.bullets[0] = slide.bullets[1];
      slide.bullets[1] = temp;
      renderSlidePreview();
      renderThumbnails();
    }
  }, 1000);
}

function addSlide() {
  const newSlide = {
    title: 'New Slide',
    bullets: ['Add your content here', 'Click Edit to modify']
  };
  presentationSlides.splice(currentSlideIndex + 1, 0, newSlide);
  currentSlideIndex++;
  renderEditor();
}

function deleteSlide() {
  if (presentationSlides.length <= 1) {
    alert('Cannot delete the last slide');
    return;
  }
  
  if (confirm('Delete this slide?')) {
    presentationSlides.splice(currentSlideIndex, 1);
    if (currentSlideIndex >= presentationSlides.length) {
      currentSlideIndex = presentationSlides.length - 1;
    }
    renderEditor();
  }
}

// Download presentation
function downloadPresentation() {
  if (!window.PptxGenJS) {
    alert('PPTX library not loaded');
    return;
  }
  
  const pptx = new PptxGenJS();
  pptx.defineLayout({ name: 'W', width: 13.33, height: 7.5 });
  pptx.layout = 'W';
  
  presentationSlides.forEach(function(slide) {
    const sl = pptx.addSlide();
    sl.background = { color: 'FFFFFF' };
    sl.addText(slide.title, { 
      x: 0.7, 
      y: 0.5, 
      w: 12, 
      h: 1.2, 
      fontSize: 32, 
      bold: true, 
      color: '1A1A1A' 
    });
    
    if (slide.bullets && slide.bullets.length > 0) {
      sl.addText(slide.bullets.map(function(bullet) {
        return { text: bullet, options: { bullet: true, breakLine: true } };
      }), {
        x: 0.9,
        y: 2.0,
        w: 11.5,
        h: 4.8,
        fontSize: 18,
        color: '495057',
        lineSpacingMultiple: 1.4
      });
    }
  });
  
  pptx.writeFile({ fileName: 'AI-Presentation.pptx' });
}

// Utility
function escapeHtml(text) {
  const div = document.createElement('div');
  div.textContent = text;
  return div.innerHTML;
}

// Keyboard navigation
document.addEventListener('keydown', function(e) {
  if (document.getElementById('page-editor').classList.contains('active')) {
    if (e.key === 'ArrowRight') nextSlide();
    if (e.key === 'ArrowLeft') prevSlide();
  }
});