canopy/src/app/chatPreprocessor.js

/*Canopy - The next generation of stoner streaming software
Copyright (C) 2024-2025 Rainbownapkin and the TTN Community

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.*/

//NPM Imports
const validator = require('validator');//No express here, so regular validator it is!

//Local Imports
const linkUtils = require('../utils/linkUtils');
const commandProcessor = require('./channel/commandProcessor');

/**
 * Class containing global server-side chat/command pre-processing logic
 */
class chatPreprocessor{
    /**
     * Instantiates a commandPreprocessor object
     * @param {commandProcessor} - Child Command Processor Object. Contains functions named after commands.
     */
    constructor(commandProcessor, tokebot){
        /**
         * Child Command Processor Object. Contains functions named after commands.
         */
        this.commandProcessor = commandProcessor;

        /**
         * Child Tokebot Object
         */
        this.tokebot = tokebot;
    }

    /**
     * Ingests a command/chat request from Chat Handler and pre-processes and processes it accordingly
     * @param {Socket} socket - Socket we're receiving the request from
     * @param {Object} data - Event payload
     */
    async preprocess(socket, data){
        //Set command object
        const commandObj = {
            socket,
            sendFlag: true,
            rawData: data,
            chatType: 'chat'
        }

        //If we don't pass sanatization/validation turn this car around
        if(!this.sanatizeCommand(commandObj)){
            return;
        }

        //split the command
        this.splitCommand(commandObj);

        //Process the command
        await this.processServerCommand(commandObj);

        //If we're going to relay this command as a message, continue on to chat processing
        if(commandObj.sendFlag){
            //Prep the message
            await this.prepMessage(commandObj);

            //Send the chat
            return commandObj;
        }

        return false;
    }

    /**
     * Sanatizes and Validates a single user chat message/command
     * @param {Object} commandObj - Object representing a single given command/chat request
     * @returns {Boolean} false if Command/Message is too long to send
     */
    sanatizeCommand(commandObj){
        //Trim and Sanatize for XSS
        commandObj.command = validator.trim(validator.escape(commandObj.rawData.msg));

        //Return whether or not the shit was long enough
        return (validator.isLength(commandObj.rawData.msg, {min: 1, max: 255}));
    }

    /**
     * Splits raw chat/command data into seperate arrays, one by word-borders and words surrounded by word-borders
     * These arrays are used to handle further command/chat processing
     * @param {Object} commandObj - Object representing a single given command/chat request
     */
    splitCommand(commandObj){
        //Split string by words
        commandObj.commandArray = commandObj.command.split(/\b/g);//Split by word-borders
        commandObj.argumentArray = commandObj.command.match(/\b\w+\b/g);//Match by words surrounded by borders
    }

    /**
     * Uses the server's Command Processor object to process the chat/command request.
     * @param {Object} commandObj - Object representing a single given command/chat request
     */
    async processServerCommand(commandObj){
        //If the raw message starts with '!' (skip commands that start with whitespace so people can send example commands in chat)
        if(commandObj.rawData.msg[0] == '!'){
            //if it isn't just an exclimation point, and we have a real command
            if(commandObj.argumentArray != null){
                //If the command processor knows what to do with whatever the fuck the user sent us
                if(this.commandProcessor != null && this.commandProcessor[commandObj.argumentArray[0].toLowerCase()] != null){
                    //Process the command and use the return value to set the sendflag (true if command valid)
                    commandObj.sendFlag = await this.commandProcessor[commandObj.argumentArray[0].toLowerCase()](commandObj, this);
                }else if(this.tokebot != null){
                    //Process as toke command if we didnt get a match from the standard server-side command processor
                    commandObj.sendFlag = await this.tokebot.tokeProcessor(commandObj);
                }
            }
        }
    }

    /**
     * Iterates through links in message and marks them by link type for later use by client-side post-processing
     * @param {Object} commandObj - Object representing a single given command/chat request
     */
    async markLinks(commandObj){
        //Setup the links array
        commandObj.links = [];

        //For each link sent from the client
        for (const link of commandObj.rawData.links){
            //Add a marked link object to our links array
            commandObj.links.push(await linkUtils.markLink(link));
        }
    }

    /**
     * Re-creates message string from processed Command Array
     * @param {Object} commandObj - Object representing a single given command/chat request
     */
    async prepMessage(commandObj){
        //Create message from commandArray
        commandObj.message = commandObj.commandArray.join('').trimStart();
        //Validate links and mark them by embed type
        await this.markLinks(commandObj);
    }
}

module.exports = chatPreprocessor;