{
    init: function(elevators, floors) {
        function is_in_array(arr,obj) {
          return (arr.indexOf(obj) != -1);
        }
        function elevatorMagic(elevator) {


          if (elevator.destinationQueue.length > 1 && elevator.destinationQueue[0] > elevator.currentFloor()) {
              // going up.
              elevator.goingUpIndicator(true);
              elevator.goingDownIndicator(false);
              elevator.destinationQueue.sort();
          }
          else if (elevator.destinationQueue.length > 1 && elevator.destinationQueue[0] < elevator.currentFloor()) {
              // going down.
              elevator.goingDownIndicator(true);
              elevator.goingUpIndicator(false);
              elevator.destinationQueue.sort().reverse();
          }


          // When somebody gets on an elevator and clicks a floor, add that to the queue.
          // only if it's not already in the queue, (todo) and we're going in the right direction.
          elevator.on("floor_button_pressed", function(floorNum) {
            if (!is_in_array(elevator.destinationQueue, floorNum)) {
              console.log('Queued ' + floorNum );
              elevator.goToFloor(floorNum);
            }
            else {
              console.log('Elevator already going to floor ' + floorNum);
            }

          });

          function callelevator(floorNum, direction) {
              // is an elevator already coming?
              var elevatorcoming = elevators.some(function (elevator, index) {
                  if (is_in_array(elevator.destinationQueue, floorNum)) {
                      console.log('Elevator ' + index + ' already on its way!');
                      return true;
                  }
                  else {
                      return false;
                  }
              });
              if (!elevatorcoming) {
                console.log('No elevator already coming, finding a candidate elevator.');
                // Find a candidate elevator and send it this way.
                var elevatorqueued = elevators.some(function (elevator, index) {
                  console.log('Trying elevator ' + index);
                  // if going up and elevator is below us.
                  if (direction == 'up' && elevator.currentFloor() <= floorNum && elevator.loadFactor < .8) {
                    console.log('Elevator ' + index + ' is below us. Sending it to floor ' + floorNum);
                    //console.log(elevator.destinationQueue);
                    elevator.goingDownIndicator(false);
                    elevator.goingUpIndicator(true);
                    elevator.goToFloor(floorNum);
                    //console.log(elevator.destinationQueue);
                    return true;
                  }
                  else if (direction == 'down' && elevator.currentFloor() >= floorNum && elevator.loadFactor < .8) {
                    console.log('Elevator ' + index + ' is above us. Sending it to floor ' + floorNum);
                    //console.log(elevator.destinationQueue());
                    elevator.goingDownIndicator(true);
                    elevator.goingUpIndicator(false);
                    elevator.goToFloor(floorNum);
                    //console.log(elevator.destinationQueue());
                    return true;
                  }
                  else if (elevator.destinationQueue.length == 0) {
                    console.log('Elevator ' + index + ' is idle. Sending it to floor ' + floorNum + '!');

                    if (elevator.currentFloor() < floorNum) {
                      elevator.goingDownIndicator(false);
                      elevator.goingUpIndicator(true);
                    }
                    else {
                      elevator.goingDownIndicator(true);
                      elevator.goingUpIndicator(false);
                    }

                    elevator.goToFloor(floorNum);
                    return true;
                  }
                  console.log('no');
                  return false;
               });
             }
          }

          // Check a floor for a button press, and if pressed, call an elevator.
          function checkforbutton(floor) {
            floor.on("up_button_pressed", function() {
                //elevator.goToFloor(floor.floorNum());
                console.log('Somebody wants to go *up* from floor *' + floor.floorNum() + '*');
                callelevator(floor.floorNum(), 'up');
            });
            floor.on("down_button_pressed", function() {
                //elevator.goToFloor(floor.floorNum());
                console.log('Somebody wants to go *down* from floor *' + floor.floorNum() + '*');
                callelevator(floor.floorNum(), 'down');
            });
          }

          // When an elevator is idle, wait until somebody clicks a button on a floor.
          elevator.on("idle", function() {
            console.log('Elevator is idle.');
            elevator.goToFloor(elevator.currentFloor());
            elevator.goingDownIndicator(true);
            elevator.goingUpIndicator(true);
            floors.forEach(checkforbutton);
          });
        }
        // Make magic with each elevator.
        elevators.forEach(elevatorMagic);
    },
    update: function(dt, elevators, floors) {
        // We normally don't need to do anything here
    }
}