// Enhanced theme toggle with smooth transitions
const toggle = document.getElementById('themeToggle');
const root = document.documentElement;
const saved = localStorage.getItem('theme') || 'dark';

// Apply saved theme
if (saved === 'light') {
  document.documentElement.classList.remove('dark');
} else {
  document.documentElement.classList.add('dark');
}

// Update theme toggle icon
const updateThemeIcon = () => {
  const icon = toggle?.querySelector('i');
  if (icon) {
    icon.setAttribute('data-lucide', document.documentElement.classList.contains('dark') ? 'sun-medium' : 'moon');
    if (window.lucide) {
      lucide.createIcons();
    }
  }
};

// Initialize theme icon
updateThemeIcon();

toggle?.addEventListener('click', () => {
  const isDark = document.documentElement.classList.toggle('dark');
  localStorage.setItem('theme', isDark ? 'dark' : 'light');
  updateThemeIcon();
  
  // Add smooth transition effect
  document.body.style.transition = 'background-color 0.3s ease, color 0.3s ease';
  setTimeout(() => {
    document.body.style.transition = '';
  }, 300);
});

// Enhanced tabs logic with smooth transitions and ARIA support
document.querySelectorAll('.tab').forEach(btn => {
  btn.addEventListener('click', () => {
    // Remove active class and ARIA attributes from all tabs
    document.querySelectorAll('.tab').forEach(b => {
      b.classList.remove('active');
      b.setAttribute('aria-selected', 'false');
    });
    
    // Add active class and ARIA attributes to clicked tab
    btn.classList.add('active');
    btn.setAttribute('aria-selected', 'true');
    
    // Get target diagram
    const target = btn.getAttribute('data-target');
    const targetDiagram = document.querySelector(target);
    
    if (targetDiagram) {
      // Hide all diagrams completely and update ARIA
      document.querySelectorAll('.diagram').forEach(d => {
        d.style.opacity = '0';
        d.style.transform = 'translateY(20px)';
        d.style.display = 'none';
        d.setAttribute('aria-hidden', 'true');
        d.classList.remove('visible');
      });
      
      // Show target diagram with fade in and update ARIA
      setTimeout(() => {
        targetDiagram.style.display = 'block';
        targetDiagram.classList.add('visible');
        targetDiagram.style.opacity = '1';
        targetDiagram.style.transform = 'translateY(0)';
        targetDiagram.setAttribute('aria-hidden', 'false');
      }, 150);
    }
  });
});

// Initialize first tab as active and show first diagram
document.addEventListener('DOMContentLoaded', () => {
  // Hide all diagrams except the first one
  document.querySelectorAll('.diagram').forEach((diagram, index) => {
    if (index === 0) {
      // First diagram should be visible
      diagram.style.display = 'block';
      diagram.style.opacity = '1';
      diagram.style.transform = 'translateY(0)';
      diagram.classList.add('visible');
      diagram.setAttribute('aria-hidden', 'false');
    } else {
      // Other diagrams should be hidden
      diagram.style.display = 'none';
      diagram.style.opacity = '0';
      diagram.style.transform = 'translateY(20px)';
      diagram.classList.remove('visible');
      diagram.setAttribute('aria-hidden', 'true');
    }
  });
  
  // Ensure Mermaid diagrams are properly initialized
  if (window.mermaid) {
    mermaid.init(undefined, document.querySelectorAll('.mermaid'));
  }
});

// Enhanced metric counters with better performance
const counters = document.querySelectorAll('.metric-value');
const easeOutCubic = t => 1 - Math.pow(1 - t, 3);
const easeOutQuart = t => 1 - Math.pow(1 - t, 4);

const animateCount = (el, to, duration = 1200) => {
  const start = performance.now();
  const from = 0;
  const isLargeNumber = to > 1000;
  const easing = isLargeNumber ? easeOutQuart : easeOutCubic;
  
  // Ensure the element has proper positioning
  el.style.position = 'relative';
  el.style.zIndex = '2';
  el.style.width = '100%';
  el.style.textAlign = 'center';
  el.style.display = 'block';
  
  const step = (now) => {
    const p = Math.min(1, (now - start) / duration);
    const v = Math.floor(from + (to - from) * easing(p));
    
    // Format number with appropriate separators
    if (to >= 1000000) {
      el.textContent = (v / 1000000).toFixed(1) + 'M';
    } else if (to >= 1000) {
      el.textContent = (v / 1000).toFixed(1) + 'K';
    } else {
      el.textContent = v.toLocaleString();
    }
    
    if (p < 1) {
      requestAnimationFrame(step);
    } else {
      // Ensure final value is exact
      if (to >= 1000000) {
        el.textContent = (to / 1000000).toFixed(1) + 'M';
      } else if (to >= 1000) {
        el.textContent = (to / 1000).toFixed(1) + 'K';
      } else {
        el.textContent = to.toLocaleString();
      }
    }
  };
  requestAnimationFrame(step);
};

// Enhanced intersection observer with better performance
const observer = new IntersectionObserver(entries => {
  entries.forEach(e => {
    if (e.isIntersecting) {
      const el = e.target;
      const count = parseInt(el.dataset.count, 10) || 0;
      
      // Add loading state
      el.classList.add('loading');
      
      // Animate with slight delay for better visual effect
      setTimeout(() => {
        animateCount(el, count);
        el.classList.remove('loading');
      }, 200);
      
      observer.unobserve(el);
    }
  });
}, { 
  threshold: 0.3,
  rootMargin: '0px 0px -50px 0px'
});

// Observe counters
counters.forEach(c => observer.observe(c));

// Enhanced VanillaTilt initialization with error handling
const initTilt = () => {
  if (window.VanillaTilt) {
    try {
      document.querySelectorAll('[data-tilt]').forEach(el => {
        VanillaTilt.init(el, { 
          max: 6, 
          speed: 400, 
          glare: true, 
          'max-glare': 0.1,
          scale: 1.02,
          gyroscope: false
        });
      });
    } catch (error) {
      console.warn('VanillaTilt initialization failed:', error);
    }
  }
};

// Initialize tilt effects
initTilt();

// Smooth scrolling for navigation links
document.querySelectorAll('a[href^="#"]').forEach(link => {
  link.addEventListener('click', (e) => {
    e.preventDefault();
    const targetId = link.getAttribute('href');
    const targetElement = document.querySelector(targetId);
    
    if (targetElement) {
      const headerHeight = document.querySelector('header')?.offsetHeight || 0;
      const targetPosition = targetElement.offsetTop - headerHeight - 20;
      
      window.scrollTo({
        top: targetPosition,
        behavior: 'smooth'
      });
    }
  });
});

// Enhanced error handling for external resources
const handleResourceError = (resource, fallback) => {
  resource.addEventListener('error', () => {
    console.warn(`Failed to load resource, using fallback`);
    if (fallback) {
      resource.src = fallback;
    }
  });
};

// Handle external script loading errors
window.addEventListener('error', (e) => {
  if (e.target.tagName === 'SCRIPT' && e.target.src) {
    console.warn(`Script failed to load: ${e.target.src}`);
  }
});

// Performance monitoring
const logPerformance = () => {
  if ('performance' in window) {
    window.addEventListener('load', () => {
      setTimeout(() => {
        const perfData = performance.getEntriesByType('navigation')[0];
        console.log(`Page load time: ${perfData.loadEventEnd - perfData.loadEventStart}ms`);
      }, 0);
    });
  }
};

// Initialize performance monitoring
logPerformance();

// Add keyboard navigation support
document.addEventListener('keydown', (e) => {
  // Tab navigation for architecture tabs
  if (e.key === 'ArrowLeft' || e.key === 'ArrowRight') {
    const activeTab = document.querySelector('.tab.active');
    if (activeTab) {
      const tabs = Array.from(document.querySelectorAll('.tab'));
      const currentIndex = tabs.indexOf(activeTab);
      let nextIndex;
      
      if (e.key === 'ArrowLeft') {
        nextIndex = currentIndex > 0 ? currentIndex - 1 : tabs.length - 1;
      } else {
        nextIndex = currentIndex < tabs.length - 1 ? currentIndex + 1 : 0;
      }
      
      tabs[nextIndex].click();
      tabs[nextIndex].focus();
    }
  }
});

// Add loading states for dynamic content
const addLoadingState = (element, duration = 1000) => {
  element.classList.add('loading');
  setTimeout(() => {
    element.classList.remove('loading');
  }, duration);
};

// Initialize all interactive elements
document.addEventListener('DOMContentLoaded', () => {
  // Add loading states to cards that might load content dynamically
  document.querySelectorAll('.card').forEach(card => {
    card.addEventListener('mouseenter', () => {
      addLoadingState(card, 500);
    });
  });
  
  // Initialize tooltips for chips
  document.querySelectorAll('.chip').forEach(chip => {
    chip.setAttribute('title', chip.textContent);
  });
});