Elevator Saga – An elevator programming game(play.elevatorsaga.com)

    for(var i = 0; i < elevators.length; ++i) {
        elevator[i].on("floor_button_pressed",
             function(floorNum){ elevator[i].goToFloor(floornum)});
    }

    for(var i = 0; i < elevators.length; ++i) {
        (function(i){
            elevator[i].on("floor_button_pressed",
                function(floorNum){ elevator[i].goToFloor(floornum)});
        })(i);
    }

    {   
        init: function(elevators, floors)  // hook up events
        {
            // these are the global wish lists that idle elevators choose from (key are floor numbers, values are number of people): 
            var wishListUp = {}, wishListDown = {}; 

            for (var i = 0, l = elevators.length; i < l; i++)
            {
                var elevator = elevators[i];
                // API: goToFloor(n) [enqueues], stop() [clears queue], currentFloor(), 
                //      goingUpIndicator([set]), goingDownIndicator([set]), loadFactor() [0..1], 
                //      destinationQueue[], checkDestinationQueue() [after manual update]

                elevator.on("idle", function()  // elevator destination queue finished
                {
                    processWishList();
                }); 

                elevator.on("floor_button_pressed", function(floorNum)  // passenger indicates where to go
                {
                    if (this.destinationQueue.filter(function (d) { return d == floorNum; }).length == 0)  // if not already enqueued
                        this.goToFloor(floorNum);  // enqueue
                    // note: passengers coming first need to be delivered first (or at least at all)
                    //       however, the elevator will check by passing, whether one destination
                    //       can be approached before the others since it comes on the way. 
                }); 

                elevator.on("passing_floor", function(floorNum, direction/*"up"/"down"*/)  // if not in destination queue
                {
                    updateIndicators(this);  // indicate next destination from here
                    // we stop here if the queue contains this destination, 
                    // or if a passenger on the global wish list want to go in our direction. 
                    // we can only hope that people check where the elevator is going. 
                    if (this.destinationQueue.filter(function(d) { return d == floorNum; }).length > 0)
                    {
                        this.destinationQueue = this.destinationQueue.filter(function(d) { return d != floorNum; });  // remove from later
                        this.destinationQueue.unshift(floorNum);  // add as immediate next destination
                        this.checkDestinationQueue();  // announce modification
                    }
                    else if (this.loadFactor() < 1.0)  // if there is some space left
                    {
                        switch (getDirection(this))
                        {
                            case 1:  // going up
                                if (wishListUp[floorNum])  // are people waiting to go up from here?
                                {
                                    //if ((1.0 - this.loadFactor()) * 10.0 - wishListUp[floorNum] > 0)  // assume capacity for 10 people with regular weight
                                    //    delete wishListUp[floorNum];  // mark as visited
                                    this.destinationQueue.unshift(floorNum);  // add as immediate next destination
                                    this.checkDestinationQueue();  // announce modification
                                }
                                break;
                            case -1: // going down
                                if (wishListDown[floorNum])  // are people waiting to go down from here?
                                {
                                    //if ((1.0 - this.loadFactor()) * 10.0 - wishListDown[floorNum] > 0)  // assume capacity for 10 people with regular weight
                                    //    delete wishListDown[floorNum];  // mark as visited
                                    this.destinationQueue.unshift(floorNum);  // add as immediate next destination
                                    this.checkDestinationQueue();  // announce modification
                                }
                                break;
                            case 0:  // final destination
                            default: 
                                break; 
                        }
                    }
                }); 

                elevator.on("stopped_at_floor", function(floorNum)  // one destination reached
                {
                    processWishList(); 
                    updateIndicators(this);  // next direction
                });
            }

            for (var i = 0, l = floors.length; i < l; i++)
            {
                var floor = floors[i];
                // API: floorNum()

                floor.on("up_button_pressed", function()  // somebody wants to go up from a certain floor
                {
                    // elevators are choosing their next best destination, 
                    // we just enqueue this into the global wish list queue: 
                    var f = this.floorNum(); 
                    if (wishListUp[f])
                        wishListUp[f]++; 
                    else
                        wishListUp[f] = 1;
                    processWishList(); 
                }); 

                floor.on("down_button_pressed", function()  // somebody wants to go down from a certain floor
                {
                    // elevators are choosing their next best destination, 
                    // we just enqueue this into the global wish list queue: 
                    var f = this.floorNum();
                    if (wishListDown[f])
                        wishListDown[f]++;
                    else
                        wishListDown[f] = 1;
                    processWishList();
                });
            }


            function processWishList()  // give idle elevators a new destination
            {
                for (var i = 0, l = elevators.length; i < l; i++)  // idle
                {
                    var elevator = elevators[i]; 
                    if (elevator.destinationQueue.length == 0)
                    {
                        var next = chooseFloor(elevator.currentFloor(), true);  // find closest wish
                        if (elevator.currentFloor() != next)
                            elevator.goToFloor(next); 
                    }
                }
            }

            function getDirection(elevator)
            {
                if (elevator.destinationQueue.length == 0)
                    return 0;  // nowhere
                else if (elevator.currentFloor() < elevator.destinationQueue[0])
                    return 1;  // up
                else
                    return -1;  // down
            }

            function chooseFloor(currentFloor, dequeue)
            {
                // choose next destination from the global wish lists for up and down, 
                // depending on a) closest distance and b) number of waiting passengers: 
                var wishList = {};  // joined up and down lists with passenger counts
                var floors = [];  // array of distinct floor numbers
                for (var i in wishListUp)
                {
                    wishList[i] = wishListUp[i]; 
                    floors.push(i); 
                }
                for (var i in wishListDown)
                    if (wishList[i])
                        wishList[i] += wishListDown[i];
                    else
                    {
                        wishList[i] = wishListDown[i];
                        floors.push(i); 
                    }
                floors.sort(function(a, b)
                    { 
                        var res = Math.abs(currentFloor - a) - Math.abs(currentFloor - b);  // by closeness asc
                        if (res == 0)
                            res = wishList[b] - wishList[a];  // by passengers waiting desc
                        return res; 
                    }); 
                if (floors.length == 0)
                    return 0;  // nothing to do, go back to base
                var next = floors[0];
                if (dequeue)
                {
                    if (wishListUp[next])
                        delete wishListUp[next]; 
                    if (wishListDown[next])
                        delete wishListDown[next];
                }
                return next; 
            }

            function updateIndicators(elevator)
            {
    return;  // there seems to be a bug if announcing, people do not react ..
                switch (getDirection(elevator))
                {
                    case 1:  // up
                        if (!elevator.goingUpIndicator())
                            elevator.goingUpIndicator(true);
                        if (elevator.goingDownIndicator())
                            elevator.goingDownIndicator(false);
                        break; 

                    case -1:  // down
                        if (elevator.goingUpIndicator())
                            elevator.goingUpIndicator(false);
                        if (!elevator.goingDownIndicator())
                            elevator.goingDownIndicator(true);
                        break; 

                    case 0:  // nowhere
                    default: 
                        if (elevator.goingUpIndicator())
                            elevator.goingUpIndicator(false);
                        if (elevator.goingDownIndicator())
                            elevator.goingDownIndicator(false);
                        break; 
                }
            }
        },

        update: function(time, elevators, floors)  // loop during operation, called each frame
        {
        }, 

        vendor: 'frevd'
    }