elevator-saga/elevator.js

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

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

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

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

		// Register floor button presses
		floors.forEach(function (floor) {
			floor.on("up_button_pressed", function() { requests[UP].add(floor.floorNum); });
			floor.on("down_button_pressed", function() { requests[DOWN].add(floor.floorNum); });
		});


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

		function getClosestFloor(currentFloor, floorList){
			let distance = floorCount;
			let closestFloor = currentFloor;
			floorList.forEach(function(floorNum) {
				let newDistance = Math.abs(currentFloor - floorNum);
				if (newDistance < distance) {
					closestFloor = floorNum;
					distance = newDistance;
				}
			})
			return closestFloor;
		}

		// ----
		// Individual elevators
		// ----

		elevators.forEach(function (elevator) {
		elevator.on("floor_button_pressed", function(floorNum) { destinations.add(floorNum); });

		// 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 variables
			let status = UP;
			let destinations = new Set();

			// Go to designated starting floor
			console.log("Sending elevator[" + elevatorIndex + "] to floor[" + restFloors[0] + "]")
			elevator.goToFloor(restFloors[0]);

			elevator.on("idle", function() {
				status = IDLE;
				if (requests[UP].size == 0 && requests[DOWN].size == 0 && destinations.size == 0) {
					elevator.goToFloor(restFloors[1]);
				} else {
					let allStops = new Set([...destinations, ...requests[UP], ...requests[DOWN]]);
					elevator.goToFloor(getClosestFloor(elevator.currentFloor(), allStops));
				}
			});

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

			elevator.on("stopped_at_floor", function(floorNum) {
				requests[UP].delete(floorNum);
				requests[DOWN].delete(floorNum);
				destinations.delete(floorNum);

				if (destinations.size > 0 || requests[UP] > 0 || requests[DOWN] > 0) {
					let allStops = new Set([...destinations, ...requests[UP], ...requests[DOWN]]);
					elevator.goToFloor(getClosestFloor(elevator.currentFloor(), allStops));
				}
			});
		});
	},

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