import { c as createNamespace, n as numericProp, m as makeNumericProp, e as extend, g as getZIndexStyle, d as addUnit, D as useEventListener, I as Icon, N as inBrowser, a0 as getScrollParent, P as getScrollTop, w as withInstall } from "./index-487cde8c.js";
import { d as defineComponent, r as ref, a as computed, o as onMounted, p as onActivated, V as onDeactivated, w as watch, c as createVNode, m as mergeProps, T as Teleport, z as nextTick } from "./index-5e4623ce.js";
function throttle(action, delay) {
  let timeout = null;
  let lastRun = 0;
  return function(...args) {
    if (timeout) {
      return;
    }
    const elapsed = Date.now() - lastRun;
    const runCallback = () => {
      lastRun = Date.now();
      timeout = false;
      action.apply(this, args);
    };
    if (elapsed >= delay) {
      runCallback();
    } else {
      timeout = setTimeout(runCallback, delay);
    }
  };
}
const [name, bem] = createNamespace("back-top");
const backTopProps = {
  right: numericProp,
  bottom: numericProp,
  zIndex: numericProp,
  target: [String, Object],
  offset: makeNumericProp(200),
  immediate: Boolean,
  teleport: {
    type: [String, Object],
    default: "body"
  }
};
var stdin_default = defineComponent({
  name,
  inheritAttrs: false,
  props: backTopProps,
  emits: ["click"],
  setup(props, {
    emit,
    slots,
    attrs
  }) {
    let shouldReshow = false;
    const show = ref(false);
    const root = ref();
    const scrollParent = ref();
    const style = computed(() => extend(getZIndexStyle(props.zIndex), {
      right: addUnit(props.right),
      bottom: addUnit(props.bottom)
    }));
    const onClick = (event) => {
      var _a;
      emit("click", event);
      (_a = scrollParent.value) == null ? void 0 : _a.scrollTo({
        top: 0,
        behavior: props.immediate ? "auto" : "smooth"
      });
    };
    const scroll = () => {
      show.value = scrollParent.value ? getScrollTop(scrollParent.value) >= +props.offset : false;
    };
    const getTarget = () => {
      const {
        target
      } = props;
      if (typeof target === "string") {
        const el = document.querySelector(target);
        if (el) {
          return el;
        }
      } else {
        return target;
      }
    };
    const updateTarget = () => {
      if (inBrowser) {
        nextTick(() => {
          scrollParent.value = props.target ? getTarget() : getScrollParent(root.value);
          scroll();
        });
      }
    };
    useEventListener("scroll", throttle(scroll, 100), {
      target: scrollParent
    });
    onMounted(updateTarget);
    onActivated(() => {
      if (shouldReshow) {
        show.value = true;
        shouldReshow = false;
      }
    });
    onDeactivated(() => {
      if (show.value && props.teleport) {
        show.value = false;
        shouldReshow = true;
      }
    });
    watch(() => props.target, updateTarget);
    return () => {
      const Content = createVNode("div", mergeProps({
        "ref": !props.teleport ? root : void 0,
        "class": bem({
          active: show.value
        }),
        "style": style.value,
        "onClick": onClick
      }, attrs), [slots.default ? slots.default() : createVNode(Icon, {
        "name": "back-top",
        "class": bem("icon")
      }, null)]);
      if (props.teleport) {
        return [createVNode("div", {
          "ref": root,
          "class": bem("placeholder")
        }, null), createVNode(Teleport, {
          "to": props.teleport
        }, {
          default: () => [Content]
        })];
      }
      return Content;
    };
  }
});
const BackTop = withInstall(stdin_default);
const index = "";
export {
  BackTop as B
};