var watermark = {
  watermark(settings){
    //默认设置
    let defaultSettings = {
      watermark_txt: "text",
      watermark_x: 20, //水印起始位置x轴坐标
      watermark_y: 20, //水印起始位置Y轴坐标
      watermark_rows: 7, //水印行数
      watermark_cols: 20, //水印列数
      watermark_x_space: 100, //水印x轴间隔
      watermark_y_space: 50, //水印y轴间隔
      watermark_color: '#aaa', //水印字体颜色
      watermark_alpha: 0.4, //水印透明度
      watermark_fontsize: '15px', //水印字体大小
      watermark_font: '微软雅黑', //水印字体
      watermark_width: 210, //水印宽度
      watermark_height: 80, //水印长度
      watermark_angle: 20, //水印倾斜度数
      watermark_type: 1
    };
    if (arguments.length === 1 && typeof arguments[0] === "object") {
    let src = arguments[0] || {};
    for (let key in src) {
      if (src[key] && defaultSettings[key] && src[key] === defaultSettings[key]) continue;
      else if (src[key]) defaultSettings[key] = src[key];
    }
  }
    let oTemp = document.createDocumentFragment();
    //获取页面最大宽度
    let page_width = Math.max(document.body.scrollWidth, document.body.clientWidth);
    let cutWidth = page_width * 0.0150;
    page_width = page_width - cutWidth;
    //获取页面最大高度
    let page_height = Math.max(document.body.scrollHeight, document.body.clientHeight) + 450;
    page_height = Math.max(page_height, window.innerHeight - 30);
    //如果将水印列数设置为0，或水印列数设置过大，超过页面最大宽度，则重新计算水印列数和水印x轴间隔
    if (defaultSettings.watermark_cols == 0 || (parseInt(defaultSettings.watermark_x + defaultSettings.watermark_width * defaultSettings.watermark_cols + defaultSettings.watermark_x_space * (defaultSettings.watermark_cols - 1)) > page_width)) {
      defaultSettings.watermark_cols = parseInt((page_width - defaultSettings.watermark_x + defaultSettings.watermark_x_space) / (defaultSettings.watermark_width + defaultSettings.watermark_x_space));
      defaultSettings.watermark_x_space = parseInt((page_width - defaultSettings.watermark_x - defaultSettings.watermark_width * defaultSettings.watermark_cols) / (defaultSettings.watermark_cols - 1));
    }
    //如果将水印行数设置为0，或水印行数设置过大，超过页面最大长度，则重新计算水印行数和水印y轴间隔
    if (defaultSettings.watermark_rows == 0 || (parseInt(defaultSettings.watermark_y + defaultSettings.watermark_height * defaultSettings.watermark_rows + defaultSettings.watermark_y_space * (defaultSettings.watermark_rows - 1)) > page_height)) {
      defaultSettings.watermark_rows = parseInt((defaultSettings.watermark_y_space + page_height - defaultSettings.watermark_y) / (defaultSettings.watermark_height + defaultSettings.watermark_y_space));
      defaultSettings.watermark_y_space = parseInt(((page_height - defaultSettings.watermark_y) - defaultSettings.watermark_height * defaultSettings.watermark_rows) / (defaultSettings.watermark_rows - 1));
    }
    let x;
    let y;
    for (let i = 0; i < defaultSettings.watermark_rows; i++) {
      y = defaultSettings.watermark_y + (defaultSettings.watermark_y_space + defaultSettings.watermark_height) * i;
      for (let j = 0; j < defaultSettings.watermark_cols; j++) {
        x = defaultSettings.watermark_x + (defaultSettings.watermark_width + defaultSettings.watermark_x_space) * j;
        let mask_div = document.createElement('div');
        mask_div.id = 'mask_div' + i + j;
        mask_div.className = 'mask_div';
        if (defaultSettings.watermark_type===1){
          mask_div.appendChild(document.createTextNode(defaultSettings.watermark_txt));
        }else{
          mask_div.style.backgroundImage = "url("+defaultSettings.watermark_txt+")";
          mask_div.style.backgroundRepeat = "no-repeat";
          mask_div.style.backgroundSize = "100% 100%";
        }

        //设置水印div倾斜显示
        mask_div.style.MozTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
        mask_div.style.msTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
        mask_div.style.OTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
        mask_div.style.transform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
        mask_div.style.visibility = "";
        mask_div.style.position = "absolute";
        mask_div.style.left = x + 'px';
        mask_div.style.top = y + 'px';
        mask_div.style.overflow = "hidden";
        mask_div.style.zIndex = "9999";
        //让水印不遮挡页面的点击事件
        mask_div.style.pointerEvents = 'none';
        mask_div.style.opacity = defaultSettings.watermark_alpha;
        mask_div.style.fontSize = defaultSettings.watermark_fontsize;
        mask_div.style.fontFamily = defaultSettings.watermark_font;
        mask_div.style.color = defaultSettings.watermark_color;
        mask_div.style.textAlign = "center";
        mask_div.style.width = defaultSettings.watermark_width + 'px';
        mask_div.style.height = defaultSettings.watermark_height + 'px';
        mask_div.style.display = "block";
        oTemp.appendChild(mask_div);
      };
    };
    document.body.appendChild(oTemp);
  }
}

export default watermark;
