V2EX with Filter.js

// ==UserScript==
// @name            V2EX with Filter
// @author            autoxbc
// @version            1.0
// @match            *://*.v2ex.com/*
// @grant            GM_addStyle
// ==/UserScript==

'use strict';

( () => {
    const buttons = document.querySelector('.topic_buttons');
    if(!buttons){
        return;
    }

    const style = `
        .ago + .small.fade {
            color:#ED090D !important;
        }
    `;
    GM_addStyle(style);

    // 删除多余空格
    [...buttons.childNodes].forEach( e => {
        if( e.nodeType === 3 ){
            e.nodeValue = e.nodeValue.trim();
        }
    } );

    // 添加 优评排序 & 内容过滤框
    const [ , good , filter , input ] = [
        ,'<a>优评</a>'
        ,'<a>过滤</a>'
        ,'<input type="text" hidden="hidden" />'
    ].map( e => html2node(e) );

    [ good , filter ].forEach( e => {
        e.href = '#;';
        e.className = 'tb';
    } );

    const cells = document.querySelectorAll('.box > .cell[id^="r_"]');
    const box = cells[0].parentNode ;
    const info = box.querySelector('.cell:not([id])');

    good.reset = () => [ ...cells , box , info , good ].forEach( e => e.removeAttribute('style') );

    good.onclick = () => {
        filter.reset();

        if( box.hasAttribute('style') )
        {
            good.reset();
        } else {
            const maxOrder = [...cells].reduce( (pre,cell) => {
                const order =    [ ...cell.querySelectorAll('span.fade') ]
                                        .reduce( (pre,cur) => {
                                            const order = /\d+/.exec(cur.textContent);
                                            return Math.max( pre , order );
                                        },0);

                cell.style = order ? `order:${ order };` : 'display:none;';

                return Math.max( pre , order );
            },0);

            box.style = `
                display:flex;
                flex-direction:column-reverse;
            `;

            info.style = `order:${ maxOrder+1 };`;

            good.style = 'font-weight:700;';
        }

        return false ;
    };

    filter.title = `
        普通字符串：abc
        正则字面量：/abc/i
        排除符号：@@abc , @@/abc/i

        注意：每次过滤在上一次结果上叠加
        如想进行全新过滤，双击输入框重置
    `.replace( /\t/g ,'').trim();

    filter.reset = () => {
        input.setAttribute('hidden','hidden');
        input.ondblclick();
    };

    filter.onclick = () => {
        good.reset();

        if( input.hasAttribute('hidden') )
        {
            input.removeAttribute('hidden');
            input.focus();
        } else {
            filter.reset();
        }

        return false ;
    };


    input.ondblclick = () => {
        input.value = '';
        input.onchange();
    };

    input.onchange = () => {
        const { value } = input ;
        if( value === '' )
        {
            nodeFilter();
            return;
        }

        const cvtRegExp = str => {
            if( /^\/(.+)\/(\w*)$/.test(str) )
            {
                const { $1 , $2 } = RegExp ;
                return new RegExp( $1 , $2 );
            } else {
                return str ;
            }
        };

        if( /^@@/.test(value) ){
            nodeFilter( cvtRegExp( value.substr(2) ) , true );
        } else {
            nodeFilter( cvtRegExp(value) );
        }
    };

    buttons.append( good , filter , input );
} )();

function html2node(str)
{
    const div = document.createElement('div');
    div.innerHTML = str.trim();

    if( isSame( 1 , div.childNodes.length , div.children.length ) ){
        return div.childNodes[0];
    } else {
        return div ;
    }

}

function isSame(...args)
{
    const callee = isSame ;

    const { length } = args ;

    if( length === 0 ){
        return true;
    }

    if( length === 1 ){
        const ele = args[0];
        if( Array.isArray(ele) ){
            return callee(...ele);
        } else {
            return true ;
        }
    }

    if( length > 1 ){
        return new Set(args).size === 1 ;
    }
}

function nodeFilter(...args)
{
    const callee = nodeFilter ;

    callee.last = callee.last || new Set();
    const { last } = callee ;

    if( args.length === 0 )
    {
        last.forEach( e => e.hidden = false );
        last.clear();

        return;
    }

    let [ findReg , reverse = false , nodeSelector , fineSelector ] = args ;

    // 附带规则，用于增强指定网站的过滤能力
    [
        [ 'v2ex.com' , '.box > .cell[id^="r_"]' ] ,
    ].some( ([ host , _nodeSelector , _fineSelector ]) => {
        if( !nodeSelector && location.href.includes(host) )
        {
            nodeSelector = _nodeSelector ;
            fineSelector = _fineSelector ;
            return true ;
        }
    } );

    [ ...document.querySelectorAll(nodeSelector) ].forEach( e => {
        const target = e.querySelector(fineSelector) || e ;
        if( contains( target.textContent , findReg ) !== reverse ){
            return;
        }

        e.hidden = true;
        last.add(e);
    } );
}

function contains( str , arg ){
    if( isString(arg) )
        return str.includes(arg);
    if( isRegExp(arg) )
        return arg.test(str);

    return false ;
}

function isRegExp(reg)
{
    return Object.prototype.toString.call(reg) === '[object RegExp]';
}

function isString(str)
{
    return !!str && typeof str === 'string' && str.constructor === String ;
}