(function () {
  // svg 实现 watermark
  function __svgWM({
    container = document.body,
    content = '请勿外传',
    width = '300px',
    height = '200px',
    fillStyle = 'rgba(184, 184, 184, 0.6)',
    fontSize = '12px',
    zIndex = 1000,
    rotate='0'
  } = {}) {
    const args = arguments[0];
    const svgStr = `
    <svg xmlns="http://www.w3.org/2000/svg" width="${width}" height="${width}">
      <text x="0%" y="0%" dy="${fontSize}"
        text-anchor="left"
        stroke="none"
        stroke-width="1"
        fill="${fillStyle}"
        style="font-size: ${fontSize};">
        ${content}
      </text>
      <text x="50%" y="50%" dy="${fontSize}"
        text-anchor="left"
        stroke="none"
        stroke-width="1"
        fill="${fillStyle}"
        style="font-size: ${fontSize};">
        ${content}
      </text>
    </svg>`;
    const base64Url = `data:image/svg+xml;base64,${window.btoa(unescape(encodeURIComponent(svgStr)))}`;
    const __wm = document.querySelector('.__wm');

    const watermarkDiv = __wm || document.createElement("div");
    const styleStr = `
      position:absolute;
      top:0;
      left:0;
      width:100%;
      height:100%;
      z-index:${zIndex};
      pointer-events:none;
      background-repeat:repeat;
      transform: rotate(${rotate}deg);
      background-image:url('${base64Url}')
    `;

    watermarkDiv.setAttribute('style', styleStr);
    watermarkDiv.classList.add('__wm');
    if (!__wm) {
      container.style.position = 'relative';
      container.insertBefore(watermarkDiv, container.firstChild);
    }
  }
  if (typeof module != 'undefined' && module.exports) {
    //CMD
    module.exports = __svgWM;
  } else if (typeof define == 'function' && define.amd) {
    // AMD
    define(function() {
      return __svgWM;
    });
  } else {
    window.__svgWM = __svgWM;
  }
})();