import Vue from 'vue'

// 自定义元素实现弹框拖拽[重点]
Vue.directive('draw', {
  inserted: function (el, binding, vNode) {
    el.setAttribute('style', 'position: fixed; z-index: 9999')
  },
  bind: function (el, bindding, vNode) {
    el.setAttribute('draggable', true)
    let left, top, width, height
    el._dragstart = function (event) {
      event.stopPropagation()
      left = event.clientX - el.offsetLeft
      top = event.clientY - el.offsetTop
      width = el.offsetWidth
      height = el.offsetHeight
    }
    el._checkPosition = function () { // 防止被拖出边界
      let width = el.offsetWidth
      let height = el.offsetHeight
      let left = Math.min(el.offsetLeft, document.body.clientWidth - width)
      left = Math.max(0, left)
      let top = Math.min(el.offsetTop, document.body.clientHeight - height)
      top = Math.max(0, top)
      el.style.left = left + 'px'
      el.style.top = top + 'px'
      el.style.width = width + 'px'
      el.style.height = height + 'px'
    }
    el._dragEnd = function (event) {
      event.stopPropagation()
      left = event.clientX - left
      top = event.clientY - top
      el.style.left = left + 'px'
      el.style.top = top + 'px'
      el.style.width = width + 'px'
      el.style.height = height + 'px'
      el._checkPosition()
    }
    el._documentAllowDraop = function (event) {
      event.preventDefault()
    }
    document.body.addEventListener('dragover', el._documentAllowDraop)
    el.addEventListener('dragstart', el._dragstart)
    el.addEventListener('dragend', el._dragEnd)
    window.addEventListener('resize', el._checkPosition)
  },

  unbind: function (el, bindding, vNode) {
    document.body.removeEventListener('dragover', el._documentAllowDraop)
    el.removeEventListener('dragstart', el._dragstart)
    el.removeEventListener('dragend', el._dragEnd)
    window.removeEventListener('resize', el._checkPosition)
    delete el._documentAllowDraop
    delete el._dragstart
    delete el._dragEnd
    delete el._checkPosition
  }
})

// v-dialogDrag: 弹窗拖拽
Vue.directive('dialogDrag',{
  bind(el, binding, vnode, oldVnode) {
      let _this = this;
      //弹框可拉伸最小宽高
      let minWidth = 820;

      let minHeight = 420;

      //初始非全屏

      let isFullScreen = false;

      //当前宽高

      let nowWidth = 0;

      let nowHight = 0;

      //当前顶部高度

      let nowMarginTop = 0;

      //获取弹框头部（这部分可双击全屏）

      const dialogHeaderEl = el.querySelector('.el-dialog__header');


      //弹窗

      const dragDom = el.querySelector('.el-dialog');

      //获取当前dialog id
      const dialogID = el.id;

      //给弹窗加上overflow auto；不然缩小时框内的标签可能超出dialog；

      dragDom.style.overflow = "hidden";

      //清除选择头部文字效果

      //dialogHeaderEl.onselectstart = new Function("return false");
      //头部加上可拖动cursor

      dialogHeaderEl.style.cursor = 'move';

      dialogHeaderEl.style.cssText += ';cursor:move;';
      dragDom.style.cssText += ';top:0px;';

      // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
      const sty = (function() {
          if (window.document.currentStyle) {
              return (dom, attr) => dom.currentStyle[attr];
          } else {
              return (dom, attr) => getComputedStyle(dom, null)[attr];
          }
      })();
      //拖拽边界优化
      let moveDown = (e) => {
          // 鼠标按下，计算当前元素距离可视区的距离
          const disX = e.clientX - dialogHeaderEl.offsetLeft;
          const disY = e.clientY - dialogHeaderEl.offsetTop;
          const screenWidth = document.body.clientWidth; // body当前宽度
          const screenHeight = document.documentElement.clientHeight; // 可见区域高度(应为body高度，可某些环境下无法获取)
          const dragDomWidth = dragDom.offsetWidth; // 对话框宽度
          const dragDomheight = dragDom.offsetHeight; // 对话框高度
          const minDragDomLeft = dragDom.offsetLeft-85;
          const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth;
          const minDragDomTop = dragDom.offsetTop-135;
          const maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomheight;
          // 获取到的值带px 正则匹配替换
          let styL = sty(dragDom, 'left');
          let styT = sty(dragDom, 'top');
          // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
          if (styL.includes('%')) {
              // eslint-disable-next-line no-useless-escape
              styL = +document.body.clientWidth * (+styL.replace(/\%/g, '') / 100);
              // eslint-disable-next-line no-useless-escape
              styT = +document.body.clientHeight * (+styT.replace(/\%/g, '') / 100);
          } else {
              styL = +styL.replace(/\px/g, '');
              styT = +styT.replace(/\px/g, '');
          }

          document.onmousemove = function (e) {
              // 通过事件委托，计算移动的距离
              let left = e.clientX - disX;
              let top = e.clientY - disY;

              // 边界处理
              if (-left > minDragDomLeft) {
                  left = -minDragDomLeft;
              } else if (left > maxDragDomLeft) {
                  left = maxDragDomLeft;
              }
              if (-top > minDragDomTop) {
                  top = -minDragDomTop;
              } else if (top > maxDragDomTop) {
                  top = maxDragDomTop;
              }

              // 移动当前元素
              dragDom.style.cssText += `;left:${left + styL}px;top:${top + styT}px;`;
          };

          document.onmouseup = function(e) {
              document.onmousemove = null;
              document.onmouseup = null;
          };
          return false;
      };

      dialogHeaderEl.onmousedown = moveDown;

      //双击头部全屏效果

      dialogHeaderEl.ondblclick = (e) => {

        //   if (isFullScreen == false) {

        //       nowHight = dragDom.clientHeight;

        //       nowWidth = dragDom.clientWidth;

        //       nowMarginTop = dragDom.style.marginTop;

        //       dragDom.style.left = 0;

        //       dragDom.style.top = 0;

        //       dragDom.style.height = "100VH";

        //       dragDom.style.width = "100VW";

        //       dragDom.style.marginTop = 0;
              
        //       dragDom.style.marginBottom = 0;

        //       isFullScreen = true;

        //       dialogHeaderEl.style.cursor = 'initial';

        //       dialogHeaderEl.onmousedown = null;

        //   } else {

        //       dragDom.style.height = "auto";

        //       dragDom.style.width = nowWidth + 'px';

        //       dragDom.style.marginTop = nowMarginTop;

        //       dragDom.style.marginBottom = 0;

        //       isFullScreen = false;

        //       dialogHeaderEl.style.cursor = 'move';

        //       dialogHeaderEl.onmousedown = moveDown;

        //   }

      }

      dragDom.onmousemove = function (e) {

        //   let moveE = e;

        //   if (e.clientX > dragDom.offsetLeft + dragDom.clientWidth - 10 || dragDom.offsetLeft + 10 > e.clientX) {

        //       dragDom.style.cursor = 'w-resize';

        //   } else if (el.scrollTop + e.clientY > dragDom.offsetTop + dragDom.clientHeight - 10) {
        //       dragDom.style.cursor = 's-resize';
        //  } else {

        //       dragDom.style.cursor = 'default';

        //       dragDom.onmousedown = null;

        //   }

        //   dragDom.onmousedown = (e) => {

        //       const clientX = e.clientX;

        //       const clientY = e.clientY;

        //       let elW = dragDom.clientWidth;

        //       let elH = dragDom.clientHeight;

        //       let EloffsetLeft = dragDom.offsetLeft;

        //       let EloffsetTop = dragDom.offsetTop;

        //       let EloffsetBottom = dragDom.offsetBottom;

        //       // dragDom.style.userSelect = 'none';

        //       let ELscrollTop = el.scrollTop;

        //       //判断点击的位置是不是为头部

        //       if (clientX > EloffsetLeft && clientX < EloffsetLeft + elW && clientY > EloffsetTop && clientY < EloffsetTop + 100) {

        //           //如果是头部在此就不做任何动作，以上有绑定dialogHeaderEl.onmousedown = moveDown;

        //       }else{

        //           document.onmousemove = function (e) {

        //               // e.preventDefault(); // 移动时禁用默认事件

        //               //左侧鼠标拖拽位置

        //               if (clientX > EloffsetLeft && clientX < EloffsetLeft + 10) {

        //                   //往左拖拽

        //                   if (clientX > e.clientX) {

        //                       dragDom.style.width = elW + (clientX - e.clientX) * 2 + 'px';

        //                   }

        //                   //往右拖拽

        //                   if (clientX < e.clientX) {

        //                       if(dragDom.clientWidth < minWidth){

        //                       }else{

        //                           dragDom.style.width = elW - (e.clientX - clientX) * 2 + 'px';

        //                       }

        //                   }

        //               }

        //               //右侧鼠标拖拽位置

        //               if (clientX > EloffsetLeft + elW - 10 && clientX < EloffsetLeft + elW) {


        //                   //往左拖拽

        //                   if (clientX > e.clientX) {

        //                       if (dragDom.clientWidth < minWidth) {

        //                       } else {

        //                           dragDom.style.width = elW - (clientX - e.clientX) * 2 + 'px';

        //                       }

        //                   }

        //                   //往右拖拽

        //                   if (clientX < e.clientX) {

        //                       dragDom.style.width = elW + (e.clientX - clientX) * 2 + 'px';

        //                   }

        //               }

        //               //底部鼠标拖拽位置

        //               if (ELscrollTop + clientY > EloffsetTop + elH - 20 && ELscrollTop + clientY < EloffsetTop + elH) {

        //                   // 往上拖拽
                          
        //                   if (clientY > e.clientY) {

        //                       if (dragDom.clientHeight < minHeight) {

        //                       } else {

        //                           dragDom.style.height = elH - (clientY - e.clientY) * 2 + 'px';
        //                           let  changeHeightSize = elH - (clientY - e.clientY) * 2;
        //                       }

        //                   }

        //                   //往下拖拽

        //                   if (clientY < e.clientY) {
        //                       dragDom.style.height = elH + (e.clientY - clientY) * 2 + 'px';
        //                       let  changeHeightSize = elH - (clientY - e.clientY) * 2;
        //                   }

        //               }

        //           };

        //           //拉伸结束

        //           document.onmouseup = function (e) {

        //               document.onmousemove = null;

        //               document.onmouseup = null;

        //           };

        //       }

        //   }

      }
  }
}),

// v-dialogDragWidth: 弹窗宽度拖大 拖小
Vue.directive('dialogDragWidth', {
  bind (el, binding, vnode, oldVnode) {
    const dragDom = binding.value.$el.querySelector('.el-dialog')

    el.onmousedown = (e) => {
      // 鼠标按下，计算当前元素距离可视区的距离
      const disX = e.clientX - el.offsetLeft

      document.onmousemove = function (e) {
        e.preventDefault() // 移动时禁用默认事件

        // 通过事件委托，计算移动的距离
        const l = e.clientX - disX
        dragDom.style.width = `${l}px`
      }

      document.onmouseup = function (e) {
        document.onmousemove = null
        document.onmouseup = null
      }
    }
  }
})
