import { isFunction, isUnDef } from '/@/utils/is';

import { ref, unref } from 'vue';



export interface ScrollToParams {

  el: any;

  to: number;

  duration?: number;

  callback?: () => any;

}



const easeInOutQuad = (t: number, b: number, c: number, d: number) => {

  t /= d / 2;

  if (t < 1) {

    return (c / 2) * t * t + b;

  }

  t--;

  return (-c / 2) * (t * (t - 2) - 1) + b;

};

const move = (el: HTMLElement, amount: number) => {

  el.scrollTop = amount;

};



const position = (el: HTMLElement) => {

  return el.scrollTop;

};

export function useScrollTo({ el, to, duration = 500, callback }: ScrollToParams) {

  const isActiveRef = ref(false);

  const start = position(el);

  const change = to - start;

  const increment = 20;

  let currentTime = 0;

  duration = isUnDef(duration) ? 500 : duration;



  const animateScroll = function () {

    if (!unref(isActiveRef)) {

      return;

    }

    currentTime += increment;

    const val = easeInOutQuad(currentTime, start, change, duration);

    move(el, val);

    if (currentTime < duration && unref(isActiveRef)) {

      requestAnimationFrame(animateScroll);

    } else {

      if (callback && isFunction(callback)) {

        callback();

      }

    }

  };

  const run = () => {

    isActiveRef.value = true;

    animateScroll();

  };



  const stop = () => {

    isActiveRef.value = false;

  };



  return { start: run, stop };

}