Fire Trap Script for Roll20. Time update help from Aaron

FireTrapScript

//A little trap


on("ready", function() {
    "use strict";

var i = 0;
const millisecondsPerSecond = 1000;  // handy conversion
let timeForFullSpin = 15 * millisecondsPerSecond; // rotate fully in 15 seconds

var ShortFire = findObjs({_type: "custfx", name: "ShortFire"})[0].id
    function FireSpin(msg, pageid)
    {
        i = 0;
        // !start
        let startOffset = (Date.now() % timeForFullSpin);
        var tokenObj = getObj(msg.selected[0]._type, msg.selected[0]._id);
        var oInterval = setInterval(function() {
            if (i == 0) 
            {
            let rotation = (( ( (Date.now()+startOffset) % timeForFullSpin ) / timeForFullSpin) * 360 );
            tokenObj.set("rotation", rotation);
            setRotate();
            }
            else clearInterval(oInterval)
        }, 150);
        
        function setRotate()
        {
            
            spawnFxBetweenPoints({x: tokenObj.get('left') + (tokenObj.get('height')/2)*Math.sin(-(Math.PI/180)*tokenObj.get('rotation')),
            y: tokenObj.get('top') + (tokenObj.get('height')/2)*Math.cos(-(Math.PI/180)*tokenObj.get('rotation'))},
            {x: tokenObj.get('left') + (tokenObj.get('height')*2)*Math.sin(-(Math.PI/180)*tokenObj.get('rotation')),
            y: tokenObj.get('top') + (tokenObj.get('height')*2)*Math.cos(-(Math.PI/180)*tokenObj.get('rotation'))},
            ShortFire,
            pageid);

            spawnFxBetweenPoints({x: tokenObj.get('left') + (tokenObj.get('height')/2)*Math.sin(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * .5),
            y: tokenObj.get('top') + (tokenObj.get('height')/2)*Math.cos(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * .5)},
            {x: tokenObj.get('left') + (tokenObj.get('height')*2)*Math.sin(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * .5),
            y: tokenObj.get('top') + (tokenObj.get('height')*2)*Math.cos(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * .5)},
            ShortFire,
            pageid);

            spawnFxBetweenPoints({x: tokenObj.get('left') + (tokenObj.get('height')/2)*Math.sin(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * 1),
            y: tokenObj.get('top') + (tokenObj.get('height')/2)*Math.cos(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * 1)},
            {x: tokenObj.get('left') + (tokenObj.get('height')*2)*Math.sin(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * 1),
            y: tokenObj.get('top') + (tokenObj.get('height')*2)*Math.cos(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * 1)},
            ShortFire,
            pageid);

            spawnFxBetweenPoints({x: tokenObj.get('left') + (tokenObj.get('height')/2)*Math.sin(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * 1.5),
            y: tokenObj.get('top') + (tokenObj.get('height')/2)*Math.cos(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * 1.5)},
            {x: tokenObj.get('left') + (tokenObj.get('height')*2)*Math.sin(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * 1.5),
            y: tokenObj.get('top') + (tokenObj.get('height')*2)*Math.cos(-(Math.PI/180)*tokenObj.get('rotation') + Math.PI * 1.5)},
            ShortFire,
            pageid);
        }
    }



    // receive message to make the thing happen.
    on("chat:message", function (msg) {
        if ('api'===msg.type && playerIsGM(msg.playerid)){
            let player = getObj('player',msg.playerid);

            if (msg.content === "!FireSpinTrap")
            {
                FireSpin(msg, player.get('lastpage'));
            }
            if (msg.content === "!FireSpinStop")
            {
                i = 1;
            }
        }
    });
});