package dk.thoerup.circuitbreaker.statistics;

import java.util.Date;
import java.util.LinkedList;

import dk.thoerup.circuitbreaker.Event;

public class LoggingStatistics extends AccountingStatistics {
	
	private LinkedList<LogEntry> log = new LinkedList<LogEntry>();

	final int maxSize = 50;

	public static class LogEntry {
		public long time;
		public Event event;
		public int count = 1;
	
		public LogEntry(Event evnt) {
			this.event = evnt;
			this.time = System.currentTimeMillis();
		}
		
		public void newRetrip() {//
			count++;
			time = System.currentTimeMillis(); 
		}
		
		@Override
		public String toString() {
			
			String str = new Date(time).toString() + (" : ") + event;
			
			if (event == Event.BreakerRetripped) {
				str += ( ", " + count + " re-trips" );
			}
			
			return str ;
		}
	}
	
	
	@Override
	public void addStatistics(Event event) {
		
		super.addStatistics(event);
		
		switch(event) {

		case BreakerReset:
			addEntry(Event.BreakerReset);
			break;
		case BreakerRetripped:
			addEntry(Event.BreakerRetripped);			
			break;
		case BreakerTripped:
			addEntry(Event.BreakerTripped);
			break;
			
		/*case InvocationBlocked:
			break;
		case InvocationFailure:			
			break;
		case Invocation:
			break;
		case BreakerAttemptReset:
			break;			
			*/
			
		default:
			break;
		}
	}
	
	private void addEntry(Event event) {
		synchronized(this) {

			if (event != Event.BreakerRetripped ) {
				log.addFirst( new LogEntry(event) ); //trip and reset are added unconditionally
			} else {
				
				if (log.size() == 0 || log.getFirst().event != Event.BreakerRetripped) {
					log.addFirst( new LogEntry(event) );
				} else {
					log.getFirst().newRetrip(); 
				}				
			}

			if(log.size() > maxSize) {
				log.removeLast();
			}

		}
	}

	public void clearLog() {
		synchronized(this) {
			log.clear();
		}
	}

	public LinkedList<LogEntry> getLog() {
		synchronized(this) {
			return new LinkedList<LogEntry>(log); //return a copy so caller can to whatever he wants, when he wants
		}
	}
	
}