package simulation;

import commandSystem.BasicInstructionQueue;
import Events.CallFromElevatorEvent;
import Events.CallFromFloorEvent;
import commandSystem.Direction;
import commandSystem.ElevatorListener;
import simulation.Elevator;
import Events.*;


public class Simulation implements ElevatorListener {
	private boolean running = false;
	private int currentFloor = 0;
	private int secondToWait = 1;
	private BasicInstructionQueue queue = new BasicInstructionQueue();
	private Elevator elevator;

	public Simulation(Elevator elevator) {
		this.elevator = elevator;
	}

	public void elevatorCall(int floor) {
		System.out.println("Call from elevator: " + floor);
		queue.computeEvent(new CallFromElevatorEvent(floor));
		update();
	}

	public void floorCall(int floor, Direction direction) {
		System.out.println("Call from floor: " + floor + " going " + direction);
		queue.computeEvent(new CallFromFloorEvent(floor, direction));
		update();
	}

	public void floorChange(Direction direction) {
		System.out.println("Floor reached: " + direction);
		boolean haveToWait;
		switch (direction) {
		case UP:
			currentFloor++;
			break;
		case DOWN:
			currentFloor--;
			break;
		}
		haveToWait = queue.computeEvent(new ReachedFloorEvent(currentFloor, direction));
		if (haveToWait) {
			long t1 = System.nanoTime();
			elevator.stop();
			running = false;
			while ((System.nanoTime() - t1) / 1_000_000_000 < secondToWait);
		}
		update();
	}

	public void emergency() {
		elevator.emergencyStop();
	}

	public void cancelEmergency() {
		queue = new BasicInstructionQueue();
		elevator.cancelEmergency();
	}

	private void update() {
		final int next = queue.getNextInstruction();
		System.out.println("Current floor: " + currentFloor);
		System.out.println("Next instruction: " + next);

		if (next == -1 || next == currentFloor) {
			System.out.println("Stopping.");
			elevator.stop();
			running = false;
			return;
		}

		else if (next > currentFloor) {
			System.out.print("Going up.");
			running = true;
			elevator.goUp();
		}
		else if (next < currentFloor) {
			System.out.print("Going down.");
			running = true;
			elevator.goDown();
		}

		if (next == currentFloor + 1 || next == currentFloor - 1) {
			System.out.print("\b (slowly).");
			running = true;
			elevator.stopNextFloor();
		}
		System.out.println("\n");
	}
}