using System;

public class WaterLevelSensor {
	private int _setPoint;
	private int _currentLevel;
	private bool _rising;
	private Mode _mode = Mode.HighLevelIndicator;
	
	
	public enum Mode { HighLevelIndicator, LowLevelIndicator };
	public event WaterLevelEventHandler Full;
	public event WaterLevelEventHandler Empty;
	public event WaterLevelEventHandler Fill;
	public event WaterLevelEventHandler Drain;
	
	public int SetPoint {
		get { return _setPoint; }
		set { _setPoint = value; }
	}
	
	public int CurrentLevel {
		get { return _currentLevel; }
		set { _currentLevel = value; }
	}
	
	public Mode SensorMode {
		get { return _mode; }
		set { _mode = value; }
	}
	
	
	public WaterLevelSensor(int setPoint, int currentLevel){
		SetPoint = setPoint;
		CurrentLevel = currentLevel;
	}
	
	private WaterLevelSensor(){ }
	
	
	public void WaterLevelChange(int amount){
		int lastLevel = CurrentLevel;
		CurrentLevel += amount;
		_rising = (CurrentLevel >= lastLevel);
		
		switch(_mode){
			case Mode.HighLevelIndicator : if(_rising){
				                               if(CurrentLevel >= SetPoint){
																				 WaterLevelEventArgs args = new WaterLevelEventArgs(CurrentLevel);
																				 OnFull(args);
																			 }else{
																				 WaterLevelEventArgs args = new WaterLevelEventArgs(CurrentLevel);
																				 OnFill(args);
																			 }
																	  }
																	  break;
			
			case Mode.LowLevelIndicator : if(!_rising){
				                               if(CurrentLevel <= SetPoint){
																				 WaterLevelEventArgs args = new WaterLevelEventArgs(CurrentLevel);
																				 OnEmpty(args);
																			 }else{
																				 WaterLevelEventArgs args = new WaterLevelEventArgs(CurrentLevel);
																				 OnDrain(args);
																			 } 
																	  }
																	  break;
		} // end switch
 }
	
	public void OnFull(WaterLevelEventArgs e){
		  if(Full != null){
				Full(e);
			}
		}
	
	public void OnEmpty(WaterLevelEventArgs e){ 
		if(Empty != null){
			 Empty(e);
		}
	}
	
	public void OnFill(WaterLevelEventArgs e){
		 if(Fill != null){
						Fill(e);
			}
	}
	
	public void OnDrain(WaterLevelEventArgs e){
		 if(Drain != null){
				Drain(e);
			}
	}
	  

	
}