import Vue from "vue";

/*

*  使用方法

*  将以下代码复制到一个js文件中，然后在入口文件main.js中import引入即可；

*  给elementUI的dialog上加上 v-dialogDrag 指令就可以实现弹窗的全屏和拉伸了。

*  给dialog设置 :close-on-click-modal="false" , 禁止点击遮罩层关闭弹出层

*  如果是form表单，不要将提交等按钮放置el-form-item，以免在上下拉伸时被隐藏

*/

// v-dialogDrag: 弹窗拖拽+水平方向伸缩

Vue.directive("dialogDrag", {
	bind(el, binding, vnode, oldVnode) {
		//弹框可拉伸最小宽高

		let minWidth = 400;

		let minHeight = 300;

		//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");

		//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 = "auto";

		//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";

		// 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);

		const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null);

		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;

			// 获取到的值带px 正则匹配替换

			let styL, styT;

			// 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 (sty.left.includes("%")) {
				styL =
					+document.body.clientWidth * (+sty.left.replace(/\%/g, "") / 100);

				styT =
					+document.body.clientHeight * (+sty.top.replace(/\%/g, "") / 100);
			} else {
				styL = +sty.left.replace(/\px/g, "");

				styT = +sty.top.replace(/\px/g, "");
			}

			document.onmousemove = function(e) {
				// 通过事件委托，计算移动的距离

				const l = e.clientX - disX;

				const t = e.clientY - disY;

				// 移动当前元素

				dragDom.style.left = `${l + styL}px`;

				dragDom.style.top = `${t + styT}px`;

				//将此时的位置传出去

				//binding.value({x:e.pageX,y:e.pageY})
			};

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

				document.onmouseup = null;
			};
		};

		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;

				isFullScreen = true;

				dialogHeaderEl.style.cursor = "initial";

				dialogHeaderEl.onmousedown = null;
			} else {
				dragDom.style.height = "auto";

				dragDom.style.width = nowWidth + "px";

				dragDom.style.marginTop = nowMarginTop;

				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;

				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";
								}
							}

							//往下拖拽

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

					//拉伸结束

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

						document.onmouseup = null;
					};
				}
			};
		};
	},
});