import { defineComponent, shallowRef, ref, computed, onMounted, openBlock, createBlock, Transition, unref, withCtx, createElementBlock, normalizeStyle, normalizeClass, withModifiers, renderSlot, createVNode, createCommentVNode } from 'vue';
import { useThrottleFn, useEventListener } from '@vueuse/core';
import { ElIcon } from '../../icon/index.mjs';
import '../../../utils/index.mjs';
import { CaretTop } from '@element-plus/icons-vue';
import '../../../hooks/index.mjs';
import { backtopProps, backtopEmits } from './backtop2.mjs';
import _export_sfc from '../../../_virtual/plugin-vue_export-helper.mjs';
import { useNamespace } from '../../../hooks/use-namespace/index.mjs';
import { easeInOutCubic } from '../../../utils/animation.mjs';
import { throwError } from '../../../utils/error.mjs';

const _hoisted_1 = ["onClick"];
const COMPONENT_NAME = "ElBacktop";
const __default__ = defineComponent({
  name: COMPONENT_NAME
});
const _sfc_main = /* @__PURE__ */ defineComponent({
  ...__default__,
  props: backtopProps,
  emits: backtopEmits,
  setup(__props, { emit }) {
    const props = __props;
    const ns = useNamespace("backtop");
    const el = shallowRef();
    const container = shallowRef();
    const visible = ref(false);
    const backTopStyle = computed(() => ({
      right: `${props.right}px`,
      bottom: `${props.bottom}px`
    }));
    const scrollToTop = () => {
      if (!el.value)
        return;
      const beginTime = Date.now();
      const beginValue = el.value.scrollTop;
      const frameFunc = () => {
        if (!el.value)
          return;
        const progress = (Date.now() - beginTime) / 500;
        if (progress < 1) {
          el.value.scrollTop = beginValue * (1 - easeInOutCubic(progress));
          requestAnimationFrame(frameFunc);
        } else {
          el.value.scrollTop = 0;
        }
      };
      requestAnimationFrame(frameFunc);
    };
    const handleScroll = () => {
      if (el.value)
        visible.value = el.value.scrollTop >= props.visibilityHeight;
    };
    const handleClick = (event) => {
      scrollToTop();
      emit("click", event);
    };
    const handleScrollThrottled = useThrottleFn(handleScroll, 300, true);
    useEventListener(container, "scroll", handleScrollThrottled);
    onMounted(() => {
      var _a;
      container.value = document;
      el.value = document.documentElement;
      if (props.target) {
        el.value = (_a = document.querySelector(props.target)) != null ? _a : void 0;
        if (!el.value) {
          throwError(COMPONENT_NAME, `target is not existed: ${props.target}`);
        }
        container.value = el.value;
      }
    });
    return (_ctx, _cache) => {
      return openBlock(), createBlock(Transition, {
        name: `${unref(ns).namespace.value}-fade-in`
      }, {
        default: withCtx(() => [
          visible.value ? (openBlock(), createElementBlock("div", {
            key: 0,
            style: normalizeStyle(unref(backTopStyle)),
            class: normalizeClass(unref(ns).b()),
            onClick: withModifiers(handleClick, ["stop"])
          }, [
            renderSlot(_ctx.$slots, "default", {}, () => [
              createVNode(unref(ElIcon), {
                class: normalizeClass(unref(ns).e("icon"))
              }, {
                default: withCtx(() => [
                  createVNode(unref(CaretTop))
                ]),
                _: 1
              }, 8, ["class"])
            ])
          ], 14, _hoisted_1)) : createCommentVNode("v-if", true)
        ]),
        _: 3
      }, 8, ["name"]);
    };
  }
});
var Backtop = /* @__PURE__ */ _export_sfc(_sfc_main, [["__file", "/Users/judai/code/d-element-plus/packages/components/backtop/src/backtop.vue"]]);

export { Backtop as default };
//# sourceMappingURL=backtop.mjs.map
