bot-u-sc.js

require('dotenv').config();
console.log("Mastodon bot starting...");
const Tusk = require('tusk-mastodon');
const fs = require('fs'),
      es = require('event-stream'),
      path1 = 'songNumberTEMP.txt',
      path2 = 'scpLikesAndRepostsTEMP.txt',
      path3 = 'totalSongsNumberTEMP.txt';
var songToPost = "",

    songNumber = 0,
    songNumData = [],
    currentSongNumStr = "",
    //in case we fail to post, store the old num
    oldSongNumStr = ""

    i_as_string = "",
    
    totalSongNum = 0,
    totalSongNumData = [],
    totalSongStr = "";    

try {
    songNumData = fs.readFileSync(path1);
    totalSongNumData = fs.readFileSync(path3);
} catch (error) {
    console.log("a READ error occurred, errno=" + error.errno + "\n")
    console.log(error)
    process.exit(error.errno);    
}

if (songNumData.length != 0) {
    songNumData.forEach(i => {
        currentSongNumStr += String.fromCharCode(i);
        oldSongNumStr = currentSongNumStr
    });
} else {
    console.log('songNumData was empty');
    console.log('make sure bot-daemon.js has read access')
    process.exit(1);
}
console.log("song number is: " + songNumData);
// the actual song read will be songNumber + 1
songNumber = parseInt(currentSongNumStr);


if (totalSongNumData.length != 0) {
    totalSongNumData.forEach(i => {
        totalSongStr += String.fromCharCode(i);
    });  
} else {
    console.log('totalSongNumData was empty');
    console.log('make sure bot-daemon.js has read access');
    process.exit(1);
}

console.log("total songs number is: " + totalSongNumData);
totalSongNum = parseInt(totalSongStr);

if (songNumber == totalSongNum) {
    songNumber = 0;
    console.log('songNumber reset to zero since reached EOF')
}

const TUSK = new Tusk({
    client_key: process.env.M_CLIENT_KEY,
    client_secret: process.env.M_CLIENT_SECRET,
    access_token: process.env.M_AUTH_TOKEN,
    timeout_ms: 60*1000,  // optional HTTP request timeout to apply to all requests.
    api_url: process.env.M_INSTANCE_URL + '/api/v1/', // defaults to https://mastodon.social/api/v1/
})

var i = 0;
var s = fs.createReadStream(path2)
    .pipe(es.split())
    .pipe(es.mapSync(function(song) {
                // pause the readstream
                s.pause();
                
                // the stream reads past the end of the file, causing a blank song to be read
                // so to keep the total to not be counted one above the actual total,
                // only increment if not blank
                if (song != '') {
                    i++;
                }

                if (i > songNumber && i_as_string == "") {
                    console.log('songToPost = ' + song);
                    songToPost = song;                   
                    i_as_string = i.toString();
                    // "MEME_FOUND" custom error to catch, but unnecessary b/c destroy() calls .on(close)
                    s.destroy("MEME_FOUND")
                    return
                } 

                s.resume();                
        })
        .on('error', function(err) {
            // error "MEME_FOUND" never called
            if (err === "MEME_FOUND") {
                console.log('Finished Reading .on(error === "MEME_FOUND")');
                console.log(err)
                totalSongStr = i.toString();
                currentSongNumStr = i_as_string;
                // finally, toot the new song
                // toot(songToPost);
                //DEBUG to circumvent toot(), remove updateSongNum() in production
                updateSongNum(currentSongNumStr)
            } else {
                console.log("error 4324324312")
                reject('Error occurred, errno=:' + err.errno + '\n', err);
                process.exit(1)
            }
        })
        // on(end) doesn't get called
        .on('end', function(){
            console.log('Finished Reading .on(end)');
            totalSongStr = i.toString();
            currentSongNumStr = i_as_string;
            // finally, toot the new song
            // toot(songToPost);
            //DEBUG to circumvent toot(), remove updateSongNum() in production
            updateSongNum(currentSongNumStr)
        })
        // on(close) gets called by mapstream.destroy() when song is found
        .on('close', function(){
            console.log('Finished Reading .on(close)');
            totalSongStr = i.toString();
            currentSongNumStr = i_as_string;
            // finally, toot the new song
            // toot(songToPost);
            //DEBUG to circumvent toot(), remove updateSongNum() in production
            updateSongNum(currentSongNumStr)
        })
    );

function toot(newSong) {
    post_frequency = process.env.POST_VISIBILITY_FREQUENCY
    _visibility = songNumber % post_frequency == 0 ? 'public' : 'unlisted'

    const params = {
        status: "this song came from  my feed on SoundCloud: ⬇️\n\n"
        + newSong + "\n\n" +
        "for more cool electronic music go here: ⬇️ \n\n"
        + "https://soundcloud.com/sour_cream_pringles" +
        "\n\n" + "#EDM #acid #electro #IDM" + "\n\n\n\n" +
        "♬♫♪ ヽ(⌐■_■)ﾉ ♪♫♬",
        visibility: "direct",
        file: "true" // forces tusk to send a multipart form request instead of a url query see tusk-mastodon/lib/mastodon.js:_buildReqOpts()
    }

    TUSK.post('statuses', params)
        .then( function (promiseObject) {
            data = promiseObject.data
            resp = promiseObject.resp
            rspCode = resp.status
            instanceURL = TUSK.apiUrl
            switch (true) {
                case (rspCode > 199 && rspCode < 300):
                    //SUCCESS
                    console.log('success! :)')
                    console.log(`here is the toot on ${instanceURL}:`)
                    console.log(`ID: ${data.id} and timestamp: ${data.created_at}`)
                    // update songNum after posting to Mastodon
                    console.log("incrementing songNumber")
                    updateSongNum(currentSongNumStr)
                    break
                default:
                    console.log(`request failed, response.statusCode= ${rspCode} statusText ${resp.statusText}`)
                    console.log("songNumber not changed:" + oldSongNumStr)
                    process.exit(1)
            }
        })
        .catch( function (err) {
            console.log("TUSK.post('statuses') failed, error = " )
            if (err.statusCode || err.code) {
                console.log(`statusCode= ${err.statusCode} err.code ${err.code}`)
            }
            console.log(err.message + "\n=======================")
            console.log(err.stack)
            console.log("songNumber not changed:" + oldSongNumStr)
            process.exit(1)
        })
}

function mastodonCallback(post_err, data, response, instanceURL) {
    if (post_err) {
        console.log("an error when tooting, errno=" + post_err.errno)
        console.log("post_err is\n" + post_err)
        console.log("data.error is\n" + data.error)
        console.log("songNumber not changed:" + oldSongNumStr)
        process.exit(1)
    } else if (data.length < 1) {
        console.log("no data")
        console.log("songNumber not changed:" + oldSongNumStr)
        process.exit(1)
    } else {
        rspCode = response.statusCode
        switch (true) {
            case (rspCode >= 200 && rspCode < 300):
                //SUCCESS
                console.log(`here is the toot on ${instanceURL}:`) 
                console.log(`ID: ${data.id} and timestamp: ${data.created_at}`)
                // update songNum after successful post
                console.log("incrementing songNumber")
                updateSongNum(currentSongNumStr)
                break
            default:
                console.log("request failed, response.statusCode= " + rspCode)
                console.log("post_err is\n " + post_err)
                console.log("data.error is\n" + data.error)
                console.log("songNumber not changed:" + oldSongNumStr)
                process.exit(1)
        }
    }
}

function updateSongNum(currentSongNumStr) {
    try {
        fs.writeFileSync(path1, currentSongNumStr);
        console.log('songNumber changed to ' + currentSongNumStr); 
        fs.writeFileSync(path3, totalSongStr);
        console.log('total songs = ' + totalSongStr);
    } catch(error) {
        console.log("a WRITE error occurred, errno=" + error.errno + "\n")
        console.log(error)
        process.exit(1)
    }
}