canopy/src/app/channel/chatBuffer.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/>.*/
const config = require('../../../config.json');
const channelModel = require('../../schemas/channel/channelSchema');

/**
 * Class representing a stored chat buffer
 */
class chatBuffer{
    /**
     * Instantiates a new chat buffer for a given channel
     * @param {channelManager} server - Parent Server Object
     * @param {Mongoose.Document} chanDB  - chanDB to rehydrate buffer from
     * @param {activeChannel} channel  - Parent Channel Object
     */
    constructor(server, chanDB, channel){
        /**
         * Parent Server Object
         */
        this.server = server;

        /**
         * Parent CHannel Object
         */
        this.channel = channel;

        //If we have no chanDB.chatBuffer
        if(chanDB == null || chanDB.chatBuffer == null){
            /**
             * RAM-Based buffer containing array of previous chats
             */
            this.buffer = [];
        //Otherwise
        }else{
            /**
             * RAM-Based buffer containing array of previous chats
             */
            this.buffer = chanDB.chatBuffer;
        }

        /**
         * Inactivity Timer, goes off after x seconds of chat inactivity
         */
        this.inactivityTimer = null;

        /**
         * Inactivity Timer Delay
         */
        this.inactivityDelay = 10;

        /**
         * Goes off after x minutes of solid chatroom activity (no inactivityTimer call in x minutes)
         */
        this.busyTimer = null;

        /**
         * Busy Timer Delay
         */
        this.busyDelay = 5;
    }

    /**
     * Adds a given chat to the chat buffer in RAM and sets any appropriate timers for DB transactions
     * @param {chat} chat - Chat object to commit to buffer
     */
    push(chat){
        //push chat into RAM buffer
        this.buffer.push(chat);
        
        //clear existing inactivity timer
        clearTimeout(this.inactivityTimer);

        //reset inactivity timer
        this.inactivityTimer = setTimeout(this.handleInactivity.bind(this), 1000 * this.inactivityDelay);

        //If busy timer is unset
        if(this.busyTimer == null){
            this.busyTimer = setTimeout(this.handleBusyRoom.bind(this), 1000 * 60 * this.busyDelay);
        }
    }

    /**
     * Removes the oldest item from the chat buffer
     * 
     * Was originally created in-case we needed to trigger timing functions
     * 
     * Left here since it seems like good form anywho, since this would be a private, or at least protected member in another language
     */
    shift(){
        this.buffer.shift();
    }

    /**
     * Called after 10 seconds of chat room inactivity
     */
    handleInactivity(){
        this.saveDB(`${this.inactivityDelay} seconds of inactivity.`);
    }

    /**
     * Called after 5 minutes of solid activity
     */
    handleBusyRoom(){
        this.saveDB(`${this.busyDelay} minutes of activity.`);
    }

    /**
     * Clears out buffer timers to prevent saving
     */
    clearTimers(){
        //clear existing timers
        clearTimeout(this.inactivityTimer);
        clearTimeout(this.busyTimer);
        this.inactivityTimer = null;
        this.busyTimer = null;
    }

    /**
     * Clears RAM-Based chat buffer and saves the result to DB
     * @param {String} name - Name of user to clear chats from. Left as null or an empty string, it will clear the entire buffer.
     */
    async clearBuffer(name){
        //Clear out DB Timers
        this.clearTimers();

        let reason = "clearing chat";

        //If we have a null or empty string passed as name
        if(name == null || name == ""){
            //Nuke that fcker
            this.buffer = [];
        //Otherwise
        }else{
            reason = `clearing ${name}'s chats`

            //Iterate through chat buffer by index
            for(let chatIndex in this.buffer){
                //If the current chat we're looking at was submitted by the given user
                if(this.buffer[chatIndex].user.toLowerCase() == name.toLowerCase()){
                    //Splice that fcker out
                    this.buffer.splice(chatIndex, 1);
                }
            }
        }

        await this.saveDB(reason);
    }

    /**
     * Saves RAM-Based buffer to Channel Document in DB 
     * @param {String} reason - Reason for DB save, formatted as 'x minutes/seconds of in/activity', used for logging purposes
     * @param {Mongoose.Document} chanDB - Channel Doc to work with, can be left empty for method to auto-find through channel name.
     */
    async saveDB(reason, chanDB){
        //Clear out DB Timers
        this.clearTimers();

        //if the server is in screamy boi mode
        if(config.verbose){
            //This should eventually be replaced by a per-channel logging feature that provides access to chan admins via web front-end
            console.log(`Saving chat buffer to channel ${this.channel.name} after ${reason}.`);
        }


        //If we wheren't handed a channel
        if(chanDB == null){
            //Now that everything is clean, we can take our time with the DB :P
            chanDB = await channelModel.findOne({name:this.channel.name});
        }

        //If we couldn't find the channel
        if(chanDB == null){
            //FUCK
            throw loggerUtils.exceptionSmith(`Unable to find channel document ${this.channel.name} while saving chat buffer!`, "chat");
        }

        //Set chan doc buffer to RAM buffer
        chanDB.chatBuffer = this.buffer;

        //save chan doc to DB.
        await chanDB.save();
    }
}

module.exports = chatBuffer;