// ==UserScript==
// @name	回到顶部（长按置底）
// @version	1.0.4.2
// @description	支持在所有页面生成一个顺滑回到顶部的按钮，修改自https://greasyfork.org/zh-CN/scripts/435303-%E5%9B%9E%E5%88%B0%E9%A1%B6%E9%83%A8
// @author	@leo
// @email	ygnh136@qq.com
// @match	*://*/*
// @license	MIT
// @namespace	https://greasyfork.org/zh-CN/users/954189
// @downloadURL none
// ==/UserScript==

;(() => {
//注入CSS
var style = document.createElement('style');
style.innerHTML = `
.GO_TO_TOP_button {
    width: 42px;
    height: 42px;
    border-radius: 8px;
    box-shadow: 0 3px 6px rgb(0 0 0 / 16%), 0 1px 2px rgb(0 0 0 / 23%);
    position: fixed;
    left: 50%;
    transform: translate(-50%,0);
    bottom: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 99999999;
    background-color: white;
    opacity: 0.5;
}
.GO_TO_TOP_button svg {
  width: 24px;
  height: 24px;
  margin: 0;
}
`;
document.head.appendChild(style);
	
// 创建页面回到顶/底部方法
const goToTop = () => {
    window.scrollTo(0, 0);
}
const goToBottom = () => {
    window.scrollTo(0,document.body.scrollHeight);
}

// 创建DOM绑定方法
	const button = document.createElement('div')
	button.className = 'GO_TO_TOP_button'
	button.innerHTML =
		'<svg class="icon" viewBox="0 0 1024 1024" version="1.1" xmlns="http://www.w3.org/2000/svg" width="200" height="200"><path d="M825.568 555.328l-287.392-289.28C531.808 259.648 523.488 256.576 515.2 256.64 514.08 256.544 513.12 256 512 256c-4.672 0-9.024 1.088-13.024 2.88-4.032 1.536-7.872 3.872-11.136 7.136l-259.328 258.88c-12.512 12.48-12.544 32.736-0.032 45.248 6.24 6.272 14.432 9.408 22.656 9.408 8.192 0 16.352-3.136 22.624-9.344L480 364.288 480 928c0 17.696 14.336 32 32 32s32-14.304 32-32L544 362.72l236.192 237.728c6.24 6.272 14.496 9.44 22.688 9.44s16.32-3.104 22.56-9.312C838.016 588.128 838.048 567.84 825.568 555.328z" ></path><path d="M864 192 160 192C142.336 192 128 177.664 128 160s14.336-32 32-32l704 0c17.696 0 32 14.336 32 32S881.696 192 864 192z"></path></svg>'

//长按0.5秒直达底部，不足0.5秒直达顶部
let pressTimer;
let isLongPress = false;
button.addEventListener("touchstart", (event) => {
    event.preventDefault();
    pressTimer = setTimeout(() => {
        isLongPress = true;
        goToBottom();
    }, 500);
});
button.addEventListener("touchend", (event) => {
    event.preventDefault();
    clearTimeout(pressTimer);
    if (!isLongPress) {
        goToTop();
    }
    isLongPress = false;
});

// 默认隐藏按钮
button.style.display = 'none'
document.body.appendChild(button)

//不在顶部时显示按钮，静止2秒后隐藏按钮
let timer;
window.addEventListener('scroll', function() {
    clearTimeout(timer);
    button.style.display = window.pageYOffset > 50 ? 'flex' : 'none';
    timer = setTimeout(() => {
        button.style.display = 'none';
    }, 2000);
});

// 监听滚动并渲染节点
	document.addEventListener('scroll', onScroll)
})()