elevatorSaga.js

{
    init: function(elevators, floors) {
        function randomElevator(elevators) {
            return elevators[Math.floor(Math.random() * elevators.length)];
        };
        
        function bestElevator(floorNum) {
            var bestElevator = elevators[0];
            
            var emptyElevators = [];
            
            for (var e = 0; e < elevators.length; e++) {
                var elevator = elevators[e];
                
                if (elevator.loadFactor() === 0) {
                    emptyElevators.push(elevator);
                }
            }
            
            if (emptyElevators.length !== 0) {
                return randomElevator(emptyElevators);
            }
            
            var nonEmptyElevators = [];
            
            for (var e = 0; e < elevators.length; e++) {
                var elevator = elevators[e];
                
                if (elevator.loadFactor() !== 1) {
                    nonEmptyElevators.push(elevator);
                }
            }
            
            if (nonEmptyElevators.length === 0) {
                return randomElevator(elevators);
            }
            
            bestElevator = nonEmptyElevators[0];
            
            var onRouteElevators = [];
            
            for (var e = 0; e < nonEmptyElevators.length; e++) {
                var elevator = nonEmptyElevators[e];
                
                if (elevator.goingUp) {
                    if (elevator.currentFloor() < floorNum) {
                        onRouteElevators.push(elevator);
                    }
                } else {
                    if (elevator.currentFloor() > floorNum) {
                        onRouteElevators.push(elevator);
                    }
                }
            }
            
            if (onRouteElevators.length === 0) {
                onRouteElevators = nonEmptyElevators;
            }
            
            bestElevator = onRouteElevators[0];
            
            for (var e = 0; e < onRouteElevators.length; e++) {
                var elevator = onRouteElevators[e];
                
                if (bestElevator.loadFactor() > elevator.loadFactor()) {
                    bestElevator = elevator;
                }
            }
            
            return bestElevator;
        }
        
        function elevatorToFloor(elevator, floorNum) {
            if (elevator.goingUp) {
                if (elevator.currentFloor() > floorNum) {
                    elevatorDown(elevator, floorNum);
                } else {
                    elevatorUp(elevator, floorNum);
                }
            } else {
                if (elevator.currentFloor() < floorNum) {
                    elevatorUp(elevator, floorNum);
                } else {
                    elevatorDown(elevator, floorNum);
                }
            }
            
            refreshElevatorQueue(elevator);
        }
        
        function elevatorDown(elevator, floorNum) {
            if (elevator.downQueue.indexOf(floorNum) !== -1) {
                return;
            }
            
            elevator.downQueue.push(floorNum);
            elevator.downQueue.sort().reverse();
        }
        
        function elevatorUp(elevator, floorNum) {
            if (elevator.upQueue.indexOf(floorNum) !== -1) {
                return;
            }
            
            elevator.upQueue.push(floorNum);
            elevator.upQueue.sort();
        }
        
        function elevatorRemoveFloor(elevator, floorNum) {
            if (elevator.upQueue.indexOf(floorNum) !== -1) {
                elevator.upQueue.splice(elevator.upQueue.indexOf(floorNum), 1);
            }
            
            if (elevator.downQueue.indexOf(floorNum) !== -1) {
                elevator.downQueue.splice(elevator.downQueue.indexOf(floorNum), 1);
            }
        }
        
        function refreshElevatorQueue (elevator) {
            if (elevator.goingUp) {
                elevator.destinationQueue = elevator.upQueue;
            } else {
                elevator.destinationQueue = elevator.downQueue;
            }
            
            elevator.checkDestinationQueue();
        }
        
        function elevatorButtonPressed(elevator) {
            return function (floorNum) {
                elevatorToFloor(elevator, floorNum);
            };
        }
        
        function elevatorStopped(elevator) {
            return function (floorNum) {
                elevatorRemoveFloor(elevator, floorNum);
            };
        }
        
        function elevatorIdle(elevator) {
            return function () {
                elevator.goingUp = !elevator.goingUp;
            
                var homeFloor = Math.floor(floors.length / 2);
                
                if (elevator.goingUp) {
                    if (elevator.currentFloor() < homeFloor) {
                        elevatorToFloor(elevator, homeFloor);
                    } else {
                        elevatorToFloor(elevator, floors.length - 1);
                    }
                } else {
                    if (elevator.currentFloor() > homeFloor) {
                        elevatorToFloor(elevator, homeFloor);
                    } else {
                        elevatorToFloor(elevator, 0);
                    }
                }
            };
        }

        for (var e = 0; e < elevators.length; e++) {
            var elevator = elevators[e];
            
            elevator.goingUp = true;
            elevator.upQueue = [];
            elevator.downQueue = [];
            
            elevator.on("floor_button_pressed", elevatorButtonPressed(elevator));
            elevator.on("stopped_at_floor", elevatorStopped(elevator));
            elevator.on("idle", elevatorIdle(elevator));
        }
                
        function handleFloorUp (floor) {
            return function () {
                var elevator = bestElevator(floor.floorNum());
                
                elevatorToFloor(elevator, floor.floorNum());
            }
        }
        
        function handleFloorDown (floor) {
            return function () {
                var elevator = bestElevator(floor.floorNum());
                
                elevatorToFloor(elevator, floor.floorNum());
            }
        }
        
        for (var f = 0; f < floors.length; f++) {
            var floor = floors[f];
            
            floor.on("up_button_pressed", handleFloorUp(floor));
            floor.on("down_button_pressed", handleFloorDown(floor));
        }
    },
    update: function(dt, elevators, floors) {
        // We normally don't need to do anything here
    }
}