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, ignoredFloors = new Set(), direction = IDLE){
			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(elevators, elevatorIndex, destinations, requests, restFloors) {
			elevator = elevators[elevatorIndex]
			if (elevator.loadFactor() < 0.8) {
				if (requests[UP].size > 0 || requests[DOWN].size > 0 || destinations.size > 0) {
					let allStops = new Set([...destinations, ...requests[UP], ...requests[DOWN]]);
					try {
						floorNum = getClosestFloor(elevator.currentFloor(), allStops)
						//console.log("> Sending elevator[" + elevatorIndex + "] to floor[" + floorNum + "]");
						elevator.goToFloor(floorNum);
					} catch (e) {
						//console.log("> No closest floor. Sending elevator[" + elevatorIndex + "] to rest floor[" + restFloors[1] + "]");
						elevator.goToFloor(restFloors[1]);
					}
				} else {
					//console.log("> Sending elevator[" + elevatorIndex + "] to rest floor[" + restFloors[1] + "]");
					elevator.goToFloor(restFloors[1]);
				}
			} else {
				try {
					floorNum = getClosestFloor(elevator.currentFloor(), destinations)
					console.log("> Sending elevator[" + elevatorIndex + "] to destination floor[" + floorNum + "]");
					elevator.goToFloor(floorNum);
				} catch (e) {
					//console.log("> No closest floor. Sending elevator[" + elevatorIndex + "] to rest floor[" + restFloors[1] + "]");
					elevator.goToFloor(restFloors[1]);
				}
			}
		}

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

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

			//console.log("Closest is elevator[" + closestElevator + "]")
			return closestElevator;
		}

		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.level);
			});
			floor.on("down_button_pressed", function() {
				//console.log("> Down request on floor[" + floor.level + "]");
				requests[DOWN].add(floor.level);
			});
		});

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

		elevators.forEach(function (elevator, elevatorIndex) {

			// Elevator info and variables
			let destinations = new Set();
			const restFloors = [
				elevatorIndex * Math.floor(floorCount / (elevatorCount + 1)),
				(elevatorIndex + 1) * Math.floor(floorCount / (elevatorCount + 1)),
				(elevatorIndex + 2) * Math.floor(floorCount / (elevatorCount + 1))
			]

			// Start
			setDirection(elevator, UP); // Starts on the ground floor
			console.log("> Elevator[" + elevatorIndex + "] rest floors are " + restFloors[0] + ", " + restFloors[1] + ", and " + restFloors[2] + ". Starting at " + restFloors[0] + ".")
			elevator.goToFloor(restFloors[0]); // Nearest 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(elevators, elevatorIndex, destinations, requests, restFloors);
				}
			});

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

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

			// 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);
			});
		});
	},

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