// 记录防抖定时器和绑定的函数，方便销毁时解绑
let resizeTimer = null;
let boundResizeFn = null;

export function initScale(options) {
  const {
    wrapperId = 'screen-wrapper',
    designWidth = 1920,
    designHeight = 1080
  } = options;

  const wrapper = document.getElementById(wrapperId);
  if (!wrapper) {
    console.error(`未找到ID为 ${wrapperId} 的大屏容器`);
    return;
  }

  // 核心计算逻辑
  const calcAndApplyScale = () => {
    const clientWidth = window.innerWidth;
    const clientHeight = window.innerHeight;

    const scaleX = clientWidth / designWidth;
    const scaleY = clientHeight / designHeight;

    // 取最小比例，保证等比缩放且全部可见
    const scale = Math.min(scaleX, scaleY);

    // 应用缩放，配合 CSS 的绝对定位居中
    wrapper.style.transform = `scale(${scale}) translate(-50%, -50%)`;
  };

  // 防抖处理：避免窗口拖拽时频繁触发重绘引发卡顿
  boundResizeFn = () => {
    if (resizeTimer) clearTimeout(resizeTimer);
    resizeTimer = setTimeout(() => {
      calcAndApplyScale();
    }, 100);
  };

  // 1. 初始化执行一次
  calcAndApplyScale();

  // 2. 挂载监听
  window.addEventListener('resize', boundResizeFn);
}

// 销毁函数：在 Vue 组件销毁前调用，防止内存泄漏
export function destroyScale() {
  if (boundResizeFn) {
    window.removeEventListener('resize', boundResizeFn);
    boundResizeFn = null;
  }
  if (resizeTimer) {
    clearTimeout(resizeTimer);
    resizeTimer = null;
  }
}