// ==UserScript==
// @name           HotKey Next Page
// @namespace      hzhbest
// @author         hzhbest
// @version        1.3
// @description    按左右键快速翻页，也可点击浮动按钮快速翻页
// @include        http://*
// @include        https://*
// @license        MIT
// @downloadURL none
// ==/UserScript==

// original author : scottxp@126.com (https://userscripts-mirror.org/scripts/show/87895)
// mod by hzhbest  : add hilite and float buttons

const nextStrs = [
    "下一页",
    "下页",
    "下一页 »",
    "下一节",
    "下一章",
    "下一篇",
    "后一章",
    "后一篇",
    "后页>",
    "»",
    "next",
    "next page",
    "old",
    "older",
    "earlier",
    "下頁",
    "下一頁",
    "后一页",
    "后一頁",
    "翻下页",
    "翻下頁",
    "后页",
    "后頁",
    "下翻",
    "下一个",
    "下一张",
    "下一幅",
];

const lastStrs = [
    "上一页",
    "上页",
    "« 上一页",
    "上一节",
    "上一章",
    "上一篇",
    "前一章",
    "前一篇",
    "<前页",
    "«",
    "previous",
    "prev",
    "previous page",
    "new",
    "newer",
    "later",
    "上頁",
    "上一頁",
    "前一页",
    "前一頁",
    "翻上页",
    "翻上頁",
    "前页",
    "前頁",
    "上翻",
    "上一个",
    "上一张",
    "上一幅",
];

const GeneralXpaths = [
    ["//a[(text()='", "')]"],
    ["//a[@class='", "']"],
    ["//input[@type='button' and @value='", "']"],
];

//编辑下面的数组来自定义规则
const SpecialXpaths = [
    {
        //匹配的url
        urls: ["http://www.google.com"],
        //上一页节点的xpath
        last: "//a[@id='pnprev']",
        //下一页节点的xpath
        next: "//a[@id='pnnext']",
    },
    {
        urls: ["bilibili.com"],
        last: '//li[@class="be-pager-prev"]',
        next: '//li[@class="be-pager-next"]',
    },
];
const LEFT = 37;
const RIGHT = 39;
const css = `.__hkbtn {outline: 3px solid #bb1a6a; font-size: larger;} 
            .__hkbse {position: fixed; z-index: 1000; right: 2em; bottom: 5em; background: #fff9;} 
            .__hkbse>div:first-of-type {display: none;}
            .__hkbse:hover>div:first-of-type {display: inline-block;}
            .__hkfbtn {width: 4em; height: 3em; display: inline-block; border: 2px solid #8a8a8a8a; 
                cursor: pointer; text-align: center; font-size: 1.5em; line-height: 3em; opacity: 0.7;} 
            .__hkfbtn.disabled {opacity: 0.3;}
            .__hkfbtn:hover {opacity: 1; background: #fbcf84dd;}
            `;
addCSS(css);

var lnode = getNode(LEFT);
var rnode = getNode(RIGHT);
if (!!lnode || !!rnode) {
    var bnode = creaElemIn('div', document.body);
    bnode.className = '__hkbse';
    var lbutton = creaElemIn('div', bnode);
    var rbutton = creaElemIn('div', bnode);
    lbutton.className = rbutton.className = '__hkfbtn disabled';
    lbutton.innerHTML = "＜";
    rbutton.innerHTML = "＞";
    if (!!lnode && lnode.style.display !== 'none') {
        lnode.classList.add('__hkbtn') ;
        lbutton.classList.remove('disabled');
        if (lnode.textContent.length > 0) lbutton.innerHTML = lnode.textContent.substring(0,3);
        lbutton.title = lnode.textContent + ((!!lnode.href)? '\n' + lnode.href : '');
        lbutton.addEventListener('click', ()=>{click(lnode);}, false);
    }
    if (!!rnode && rnode.style.display !== 'none') {
        rnode.classList.add('__hkbtn') ;
        rbutton.classList.remove('disabled');
        if (rnode.textContent.length > 0) rbutton.innerHTML = rnode.textContent.substring(0,3);
        rbutton.title = rnode.textContent + ((!!rnode.href)? '\n' + rnode.href : '');
        rbutton.addEventListener('click', ()=>{click(rnode);}, false);
    }
}

function creaElemIn(tagname, destin) {
    let theElem = destin.appendChild(document.createElement(tagname));
    return theElem;
}

function addCSS(css) {
    let stylenode = creaElemIn('style',document.getElementsByTagName('head')[0]);
    stylenode.textContent = css;
    stylenode.type = 'text/css';
    stylenode.id = 'ali_c_toc';
}

function checkKey(e) {
    if (e.ctrlKey || e.shiftKey || e.altKey || e.metaKey) return;
    if (checkTextArea(e.target)) return;
    var node;
    if (e.keyCode == LEFT && !!lnode) {
        click(lnode);
    }
    if (e.keyCode == RIGHT && !!rnode) {
        click(rnode);
    }
}

function checkTextArea(node) {
    var name = node.localName.toLowerCase();
    if (name == "textarea" || name == "input" || name == "select") {
		return true;
	}
    if (name == "div" && (node.id.toLowerCase().indexOf("textarea") != -1 || node.contentEditable !== false)) {
        return true;
	}
    return false;
}

function click(node) {
    if (node.onclick) node.onclick();
    if (node.click) node.click();
    if (node.href) location.href = node.href;
}
function xpath(query) {
    return unsafeWindow.document.evaluate(
        query,
        document,
        null,
        XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE,
        null
    );
}
function getNode(keyCode) {
    var node = getNodeByGeneralXpath(keyCode);
    if (!node) node = getNodeBySpecialXpath(keyCode);
    return node;
}
function getNodeByGeneralXpath(keyCode) {
    var strs;
    if (keyCode == LEFT) strs = lastStrs;
    else if (keyCode == RIGHT) strs = nextStrs;
    else return null;
    var x = GeneralXpaths;
    for (var i in x) {
        for (var j in strs) {
            var query = x[i][0] + strs[j] + x[i][1];
            var nodes = xpath(query);
            if (nodes.snapshotLength > 0) return nodes.snapshotItem(0);
        }
    }
    return null;
}
function getNodeBySpecialXpath(keyCode) {
    var s = SpecialXpaths;
    for (var i in s) {
        if (checkXpathUrl(s[i].urls)) {
            if (keyCode == LEFT) {
                return xpath(s[i].last).snapshotItem(0);
            } else if (keyCode == RIGHT) {
                return xpath(s[i].next).snapshotItem(0);
            }
        }
    }
    return null;
}
function checkXpathUrl(urls) {
    for (var i in urls) if (location.href.indexOf(urls[i]) >= 0) return true;
    return false;
}
if (top.location != self.location) return;
unsafeWindow.document.addEventListener("keydown", checkKey, false);