elevator-saga/elevator.js

{
	init: function(elevators, floors) {
		console.clear();

		// Get elevator/building info
		let elevatorCount = elevators.length;
		let floorCount    = floors.length;
		let topFloor      = floorCount - 1;
		let bottomFloor   = 0;

		console.log("Starting (" + floorCount + " floors; " + elevatorCount + " elevator" + ((floorCount == 1) ? "s" : "") +")...");

		// Direction constants
		const UP   = 0;
		const DOWN = 1;
		const IDLE = 2;

		// Create a data structure for floor requests
		let requests = [new Set(), new Set()];

		// ----
		// Functions
		// ----

		function getClosestFloor(currentFloor, floorList, direction = IDLE, ignoredFloors = new Set()){
			let closestFloor = currentFloor;
			let distance     = floorCount;
			let newDistance  = distance;

			floorList.forEach(function(floorNum) {
				switch (direction) {
					case UP:
						newDistance = floorNum - currentFloor;
					case DOWN:
						newDistance = currentFloor - floorNum;
					case IDLE:
						newDistance = Math.abs(floorNum - currentFloor);
				}
				if (newDistance < distance && newDistance > 0 && !(ignoredFloors.has(floorNum))) {
					closestFloor = floorNum;
					distance = newDistance;
				}
			})

			if (closestFloor != currentFloor) {
				return closestFloor;
			} else {
				throw new Error("No floor in selected direction");
			}
		}

		function sendToNext(elevator, destinations, requests, restFloors) {
			if (elevator.loadFactor() < 1) {
				if (requests[UP].size > 0 || requests[DOWN].size > 0 || destinations.size > 0) {
					let allStops = new Set([...destinations, ...requests[UP], ...requests[DOWN]]);
					try {
						elevator.goToFloor(getClosestFloor(elevator.currentFloor(), allStops));
					} catch (e) {
						elevator.goToFloor(restFloors[1]);
					}
				}
			} else {
				elevator.goToFloor(getClosestFloor(elevator.currentFloor(), destinations));
			}
		}

		function bringClosestElevator(floorNum) {
			let closestElevator = 0;
			let distance        = floorCount;
			let newDistance     = distance;

			elevators.forEach(function (elevator) {
				newDistance = Math.abs(elevator.currentFloor() - floorNum);
				if (newDistance < distance) {
					distance = newDistance;
					closestElevator = elevators.indexOf(elevator);
				}
			});

			elevators[closestElevator].goToFloor(floorNum);
		}

		function setDirection(elevator, direction){
			switch (direction) {
				case UP:
					elevator.goingUpIndicator(true);
					elevator.goingDownIndicator(false);
					break
				case DOWN:
					elevator.goingUpIndicator(false);
					elevator.goingDownIndicator(true);
					break
				default:
					elevator.goingUpIndicator(true);
					elevator.goingDownIndicator(true);
			}
		}

		// ----
		// Floors
		// ----

		floors.forEach(function (floor) {
			floor.on("up_button_pressed", function() {
				console.log("> Up request on floor[" + floor.level + "]");
				requests[UP].add(floor.floorNum);
				bringClosestElevator(floor.floorNum);
			});
			floor.on("down_button_pressed", function() {
				console.log("> Down request on floor[" + floor.level + "]");
				requests[DOWN].add(floor.floorNum);
				bringClosestElevator(floor.floorNum);
			});
		});

		// ----
		// Elevators
		// ----

		elevators.forEach(function (elevator) {

			// Basic elevator info
			const elevatorIndex = elevators.indexOf(elevator);
			const restFloors = [
				(elevatorIndex + 0) * Math.floor(floorCount / (elevatorCount + 1)),
				(elevatorIndex + 1) * Math.floor(floorCount / (elevatorCount + 1)),
				(elevatorIndex + 2) * Math.floor(floorCount / (elevatorCount + 1))
			]

			elevator.on("floor_button_pressed", function(floorNum) {
				console.log("> Pressed floor[" + floorNum + "] on elevator[" + elevatorIndex + "]");
				destinations.add(floorNum);
				sendToNext(elevator, destinations, requests, restFloors);
			});

			// Elevator variables
			let destinations = new Set();

			// Start
			setDirection(elevator, UP); // Starts on the ground floor
			console.log("> Sending elevator[" + elevatorIndex + "] to floor[" + restFloors[0] + "]");
			elevator.goToFloor(restFloors[0]); // Closest rest floor

			// Idle
			elevator.on("idle", function() {
				console.log("> Elevator[" + elevatorIndex + "] is idle")
				setDirection(elevator, IDLE);
				if (requests[UP].size == 0 && requests[DOWN].size == 0 && destinations.size == 0) {
					elevator.goToFloor(restFloors[1]);
				} else {
					sendToNext(elevator, destinations, requests, restFloors);
				}
			});

			// Passing
			elevator.on("passing_floor", function(floorNum, direction) {
				if (elevator.loadFactor() < 1) {
					if (requests[UP].has(floorNum) || requests[DOWN].has(floorNum) || destinations.has(floorNum)) {
						elevator.goToFloor(floorNum, true);
					}
				} else if (destinations.has(floorNum)) {
					elevator.goToFloor(floorNum, true);
				}
			});

			// Stopped
			elevator.on("stopped_at_floor", function(floorNum) {
				console.log("> elevator[" + elevatorIndex + "] stopped at floor[" + floorNum + "]");
				destinations.delete(floorNum);
				requests[UP].delete(floorNum);
				requests[DOWN].delete(floorNum);

				sendToNext(elevator, destinations, requests, restFloors);
			});
		});
	},

	update: function(dt, elevators, floors) {}
}