// 页面加载完成
document.addEventListener('DOMContentLoaded', function() {
  // 懒加载图片
  const lazyImages = document.querySelectorAll('img[data-src]');
  
  const imageObserver = new IntersectionObserver((entries, observer) => {
    entries.forEach(entry => {
      if (entry.isIntersecting) {
        const img = entry.target;
        img.src = img.dataset.src;
        img.classList.add('loaded');
        observer.unobserve(img);
      }
    });
  });
  
  lazyImages.forEach(img => imageObserver.observe(img));
  
  // 懒加载内容
  const lazyElements = document.querySelectorAll('.lazy-load');
  
  const elementObserver = new IntersectionObserver((entries, observer) => {
    entries.forEach(entry => {
      if (entry.isIntersecting) {
        entry.target.classList.add('loaded');
        observer.unobserve(entry.target);
      }
    });
  }, { threshold: 0.1 });
  
  lazyElements.forEach(el => elementObserver.observe(el));
});

// 初始化图表
function initChart(ctx, config) {
  return new Chart(ctx, config);
}

// 格式化数字
function formatNumber(num, decimals = 0) {
  if (num >= 100000000) {
    return (num / 100000000).toFixed(decimals) + '亿';
  } else if (num >= 10000) {
    return (num / 10000).toFixed(decimals) + '万';
  }
  return num.toLocaleString('zh-CN', { maximumFractionDigits: decimals });
}

// 格式化百分比
function formatPercent(value, decimals = 1) {
  return (value * 100).toFixed(decimals) + '%';
}

// 创建趋势指示器
function createTrendIndicator(value) {
  const isPositive = value >= 0;
  const icon = isPositive ? '↑' : '↓';
  const className = isPositive ? 'stat-change positive' : 'stat-change negative';
  return `<span class="${className}">${icon} ${Math.abs(value).toFixed(1)}%</span>`;
}

// 响应式图表配置
function getResponsiveConfig(baseConfig) {
  return {
    ...baseConfig,
    options: {
      ...baseConfig.options,
      responsive: true,
      maintainAspectRatio: false,
      plugins: {
        ...baseConfig.options?.plugins,
        legend: {
          ...baseConfig.options?.plugins?.legend,
          display: window.innerWidth > 768
        }
      }
    }
  };
}