elevator.js

// https://play.elevatorsaga.com
{
    init: function(elevators, floors) {
        function anyoneWaiting(e) {
            var c = e.currentFloor();
            var dest = _.head(e.destinationQueue);
            var bs = floors[c].buttonStates;

            if (dest === undefined || dest == c)
                return !!bs.up || !!bs.down;
            /*else if (dest > c)
                return !!bs.up;
            else
                return !!bs.down;*/
            else
                return false;
        }

        function nextPressedFloor(e) {
            var c = e.currentFloor();
            var dest = _.head(e.destinationQueue);
            var fs = e.getPressedFloors();

            if (dest === undefined || dest == c) {
                return _.min(fs, f => Math.abs(f - c));
            } else if (dest > c) {
                fs = _.filter(fs, f => f > c);
                return fs.length == 0 ? _.max(e.getPressedFloors()) : _.min(fs);
            } else {
                fs = _.filter(fs, f => f < c);
                return fs.length == 0 ? _.min(e.getPressedFloors()) : _.max(fs);
            }
        }
        
        function nextCalledFloor(e, dest, u, d) {
            var c = e.currentFloor();
            if (dest === undefined || !_.isFinite(dest))
                dest = c;

            if (e.maxPassengerCount() > 5) {
                u = _.filter(u, n => n == 0);
                d = _.filter(d, n => n == 0);
            }

            var called;
            if (dest == c) {
                if (!_.includes(e.getPressedFloors(), c)) {
                    called = _.min(_.flatten([u, d]), f => Math.abs(f - c));
                }
            } else if (dest > c) {
                called = _.min(_.filter(u, n => n > c));
            } else {
                called = _.max(_.filter(d, n => n < c));
            }

            return called === undefined || !_.isFinite(called)
                ? { dest: dest, called: false }
                : { dest: called, called: true };
        }
        
        function goAll() {
            var u = {};
            var d = {};
            _.each(floors, f => {
                if (f.buttonStates.up == "activated")
                    u[f.level.toString()] = f.level;
                if (f.buttonStates.down == "activated")
                    d[f.level.toString()] = f.level;
            });

            _.each(elevators, (e, index) => {
                var c = e.currentFloor();
                var pressedDest, dest;
                if (e.loadFactor() < 0.5 && anyoneWaiting(e)) {
                    pressedDest = c;
                    dest = { dest: c, called: true };
                } else {
                    pressedDest = nextPressedFloor(e);
                    dest = nextCalledFloor(e, pressedDest, _.values(u), _.values(d));
                }

                var { dest, called } = dest;
                if (called) {
                    delete u[dest.toString()];
                    delete d[dest.toString()];
                    e.goingUpIndicator(dest >= c);
                    e.goingDownIndicator(dest <= c);
                } else {
                    e.goingUpIndicator(false);
                    e.goingDownIndicator(false);
                }

                e.destinationQueue = [dest];
                e.checkDestinationQueue();
            });
        }
        
        _.forEach(floors, floor => {
            floor.on("up_button_pressed", goAll);
            floor.on("down_button_pressed", goAll);
        });

        _.each(elevators, elevator => {
            elevator.on("idle", goAll);
            elevator.on("floor_button_pressed", goAll);
            elevator.on("stopped_at_floor", goAll);
        });
    },
    update: function(dt, elevators, floors) {
        // We normally don't need to do anything here
    }
}