Pass challenges 1-8

elevator.js

 {
 	init: function(elevators, floors) {
 		console.clear();
-		console.log("----" + "\n");
 		console.log("Starting...");
-		console.log("----" + "\n");
 
-		let floorCount = floors.length;
-		let bottomFloor = 0;
-		let topFloor = floorCount - 1;
+		// Get elevator/building info
+		let floorCount    = floors.length;
+		let bottomFloor   = 0;
+		let topFloor      = floorCount - 1;
 		let elevatorCount = elevators.length;
 
-		let upRequestFloorSet = new Set();
-		let downRequestFloorSet = new Set();
+		// 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() {
-				console.log("Up request: " + floor.level);
-				upRequestFloorSet.add(floor.floorNum);
-			});
-
-			floor.on("down_button_pressed", function() {
-				console.log("Down request: " + floor.level);
-				downRequestFloorSet.add(floor.floorNum);
-			});
+			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
-		let elevator = elevators[0];
-		let elevatorIndex = elevators.indexOf(elevator);
+		// ----
 
-		let destinationSet = new Set();
+		elevators.forEach(function (elevator) {
+		elevator.on("floor_button_pressed", function(floorNum) { destinations.add(floorNum); });
 
-		let defaultRange = [
-			(elevatorIndex + 0) * Math.floor(floorCount / (elevatorCount + 1)),
-			(elevatorIndex + 1) * Math.floor(floorCount / (elevatorCount + 1)),
-			(elevatorIndex + 2) * Math.floor(floorCount / (elevatorCount + 1))
-		]
+		// 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 starts on floor 0; must be going up
-		elevator.goingUpIndicator(true);
-		elevator.goingDownIndicator(false);
+			// Elevator variables
+			let status = UP;
+			let destinations = new Set();
 
-		// Go to designated starting floor
-		console.log("Sending elevator[" + elevatorIndex + "] to floor[" + defaultRange[0] + "]")
-		elevator.goToFloor((elevatorIndex + 0) * Math.floor(floorCount / (elevatorCount + 1)));
+			// Go to designated starting floor
+			console.log("Sending elevator[" + elevatorIndex + "] to floor[" + restFloors[0] + "]")
+			elevator.goToFloor(restFloors[0]);
 
-		elevator.on("idle", function() {
-			console.log("Idle...");
-			elevator.goingUpIndicator(false);
-			elevator.goingDownIndicator(false);
-		});
+			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("floor_button_pressed", function(floorNum) {
-			console.log("Floor pressed: " + floorNum);
-			destinationSet.add(floorNum);
-			elevator.goToFloor(floorNum);
-		});
+			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("passing_floor", function(floorNum, direction) {
-			if(upRequestFloorSet.has(floorNum) || downRequestFloorSet.has(floorNum) || destinationSet.has(floorNum)) {
-				elevator.goToFloor(floorNum);
-			}
-		});
+			elevator.on("stopped_at_floor", function(floorNum) {
+				requests[UP].delete(floorNum);
+				requests[DOWN].delete(floorNum);
+				destinations.delete(floorNum);
 
-		elevator.on("stopped_at_floor", function(floorNum) {
-			console.log("Stopped at: " + floorNum);
-			upRequestFloorSet.delete(floorNum);
-			downRequestFloorSet.delete(floorNum);
-			destinationSet.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) {}
-}
+}