index.js

const config = require('./config')

var MongoClient = require('mongodb').MongoClient
const TelegramBot = require('node-telegram-bot-api')

var mongoGroups

MongoClient.connect(config.mongo_connection).then(function (db) { // first - connect to database
    mongoGroups = db.collection('groups')
}).then(function (res) {
    const bot = new TelegramBot(config.bot_token, { polling: true }) // second - start bot


    bot.onText(/\/config/, function (msg, match) { // request configuration keyboard to PM
        if (msg.chat.type == 'supergroup') {
            bot.getChatAdministrators(msg.chat.id).then((admins) => { // get list of admins
                if (admins.filter(x => x.user.id == msg.from.id).length > 0) { // if sender is admin
                    getConfigKeyboard(msg.chat.id).then(kbd => { // prepare keyboard
                        bot.sendMessage(msg.from.id, `*${msg.chat.title}*`, { // and sent it
                            parse_mode: "markdown",
                            reply_markup: kbd
                        })
                    })
                }
            })

        } else if (msg.chat.type == 'private') {
            bot.sendMessage(msg.chat.id, "You sould use this command in supergroups that you want to configure")
        }
    })

    // delete messages according on filters
    bot.on('message', (msg) => {
        if (msg.chat.type != 'supergroup') {
            return //we can delete messages only from supergroups 
        }
        mongoGroups.findOne({ groupId: msg.chat.id }).then(res => { // load group configuration
            msg.cfg = res

            if (isJoinedMessage(msg) || isArabicMessage(msg) || isUrlMessage(msg)) {
                bot.deleteMessage(msg.chat.id, msg.message_id)
            }
        })

        console.dir(msg) // debug output
    })

    // buttons response in menu
    bot.on('callback_query', query => {
        let groupId = Number(query.data.split("#")[0])
        let prop = query.data.split("#")[1] // get info from button
        mongoGroups.findOne({ groupId: groupId }).then(g => {
            let val = !g[prop] // switch selected button
            mongoGroups.updateOne({ groupId: groupId }, { $set: { [prop]: val } }).then(() => { // store switched value
                bot.answerCallbackQuery({
                    callback_query_id: query.id
                }).then((cb) => {
                    getConfigKeyboard(groupId).then(kbd => { // update keyboard
                        bot.editMessageReplyMarkup(kbd, {
                            chat_id: query.message.chat.id,
                            message_id: query.message.message_id
                        })
                    })
                })
            })
        })
    })

    // checks if message is 'user joined/left to jroup' 
    let isJoinedMessage = function (msg) {
        return (msg.cfg && msg.cfg.joinedMsg) && (msg.new_chat_member !== undefined || msg.left_chat_member !== undefined)
    }

    // checks if message contains arabic symbols
    let isArabicMessage = function (msg) {
        return (msg.cfg && msg.cfg.arabicMsg) && /[\u0600-\u06FF]/.test(msg.text) // testing on 'arabic' regex
    }

    // cheks if message contains url
    let isUrlMessage = function (msg) {
        if (!(msg.cfg && msg.cfg.urlMsg)) {
            return false
        }

        if (msg.entities) {
            for (let e of msg.entities) {
                if (e.type == 'url') { // url messages have type 'url'
                    return true
                }
            }
        }
        return false
    }

    let getConfigKeyboard = function (chatId) { // prepare config keyboard
        let getSetOfKeys = function (groupConfig) {
            return {
                inline_keyboard: [
                    [{
                        text: `${groupConfig.joinedMsg ? "✔️" : "❌"} | delete 'joined' messages`,
                        callback_data: `${groupConfig.groupId}#joinedMsg`
                    }], [{
                        text: `${groupConfig.arabicMsg ? "✔️" : "❌"} | delete arabic messages`,
                        callback_data: `${groupConfig.groupId}#arabicMsg`
                    }], [{
                        text: `${groupConfig.urlMsg ? "✔️" : "❌"} | delete messages with urls`,
                        callback_data: `${groupConfig.groupId}#urlMsg`
                    }]
                ]
            }
        }

        return new Promise(function (resolve, rej) {
            mongoGroups.findOne({ groupId: chatId }).then(res => {
                if (res == undefined || res.length == 0) {
                    let g = new GroupConfig(chatId)
                    mongoGroups.insertOne(g).then(() => { resolve(getSetOfKeys(g)) })

                } else {
                    resolve(getSetOfKeys(res))
                }
            })
        })
    }


}).catch(function (e) {
    console.log("FATAL :: " + e)
})

class GroupConfig {
    constructor(id) {
        this.joinedMsg = false
        this.arabicMsg = false
        this.urlMsg = false
        this.groupId = id
    }
}