/***** iframe打印
 * @param dom            打印区域的class, id
 * @param options.margin  控制页眉页脚, 默认 4mm
 * @param options.padding 打印边距, 默认 '0 0'
 * @method options.afterprint 打印结束后回调
 * @method options.cancel 取消打印后回调
 * 
 * **/


 const Print = function(dom, options) {
    if (!(this instanceof Print)) return new Print(dom, options);
  
    this.options = this.extend(
      {
        noPrint: ".no-print",
      },
      options
    );
  
    if (typeof dom === "string") {
      this.dom = document.querySelector(dom);
    } else {
      this.isDOM(dom);
      this.dom = this.isDOM(dom) ? dom : dom.$el;
    }
  
    this.init();
  };
  Print.prototype = {
    init: function() {
      var content = this.getStyle() + this.getHtml();
      this.writeIframe(content);
    },
    extend: function(obj, obj2) {
      for (var k in obj2) {
        obj[k] = obj2[k];
      }
      return obj;
    },
  
    getStyle: function() {
      var str = "",
        styles = document.querySelectorAll("style,link");
      for (var i = 0; i < styles.length; i++) {
        str += styles[i].outerHTML;
      }
   
  
  
      str +=
      "<style>" +
      (this.options.noPrint ? this.options.noPrint : ".no-print") +
      "{display:none;}</style>";
      
      str += `<style>
      @media print { 
        @page { margin: ${this.options.margin || '4mm'}; padding: ${this.options.padding || '0 0'}; width:210mm;height:290mm} 
        body {  
          -webkit-print-color-adjust:exact;-moz-print-color-adjust:exact;-ms-print-color-adjust:exact;print-color-adjust:exact; 
        } 
      }
      </style>`;
  
  
      return str;
    },
  
    getHtml: function() {
      var inputs = document.querySelectorAll("input");
      var textareas = document.querySelectorAll("textarea");
      var selects = document.querySelectorAll("select");
  
      for (var k = 0; k < inputs.length; k++) {
        if (inputs[k].type == "checkbox" || inputs[k].type == "radio") {
          if (inputs[k].checked == true) {
            inputs[k].setAttribute("checked", "checked");
          } else {
            inputs[k].removeAttribute("checked");
          }
        } else if (inputs[k].type == "text") {
          inputs[k].setAttribute("value", inputs[k].value);
        } else {
          inputs[k].setAttribute("value", inputs[k].value);
        }
      }
  
      for (var k2 = 0; k2 < textareas.length; k2++) {
        if (textareas[k2].type == "textarea") {
          textareas[k2].innerHTML = textareas[k2].value;
        }
      }
  
      for (var k3 = 0; k3 < selects.length; k3++) {
        if (selects[k3].type == "select-one") {
          var child = selects[k3].children;
          for (var i in child) {
            if (child[i].tagName == "OPTION") {
              if (child[i].selected == true) {
                child[i].setAttribute("selected", "selected");
              } else {
                child[i].removeAttribute("selected");
              }
            }
          }
        }
      }
  
      return this.dom.outerHTML;
    },
  
    writeIframe: function(content) {
      var w,
        doc,
        iframe = document.createElement("iframe"),
        f = document.body.appendChild(iframe);
      iframe.id = "myIframe";
      iframe.setAttribute(
        "style",
        "position:absolute;width:0;height:0;top:-10px;left:-10px;"
      );
     
      w = f.contentWindow || f.contentDocument;
      doc = f.contentDocument || f.contentWindow.document;
      doc.open();
      doc.write(content);
      doc.close();
      var _this = this;
      
      iframe.onload = function() {
        w.onbeforeprint = _this.options.beforeprint;
        w.onafterprint = _this.options.afterprint;
        // iframe.contentWindow.print();
        _this.toPrint(w);
        setTimeout(function() {
          document.body.removeChild(iframe);
        }, 100);
      };
    },
  
    toPrint: function(frameWindow) {
      var _t = this;
      try {
        setTimeout(function() {
          frameWindow.focus();
          try {
            if (!frameWindow.document.execCommand("print", false, null)) {
              
              frameWindow.print();
            }
          } catch (e) {
            
            frameWindow.print();
          }
          frameWindow.close();
          typeof _t.options.cancel === "function" && _t.options.cancel();
          frameWindow.onbeforeprint = null;
          frameWindow.onafterprint = null;
        }, 10);
      } catch (err) {
        console.log("err", err);
      }
    },
  
    isDOM:
      typeof HTMLElement === "object"
        ? function(obj) {
            return obj instanceof HTMLElement;
          }
        : function(obj) {
            return (
              obj &&
              typeof obj === "object" &&
              obj.nodeType === 1 &&
              typeof obj.nodeName === "string"
            );
          },
  };
//   export default Print