package dk.thoerup.traininfoservice;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Date;
import java.util.concurrent.atomic.AtomicInteger;

import org.apache.commons.lang.time.DurationFormatUtils;

import dk.thoerup.traininfoservice.db.DBConnection;

public class Statistics {
	
	private AtomicInteger stationLookupsLocation = new AtomicInteger(0);
	private AtomicInteger stationLookupsName = new AtomicInteger(0);
	private AtomicInteger stationLookupsFavorites = new AtomicInteger(0);
	private AtomicInteger departureLookups = new AtomicInteger(0);
	private AtomicInteger timetableLookups = new AtomicInteger(0);	
	private AtomicInteger departureCacheHits = new AtomicInteger(0);
	private AtomicInteger timetableCacheHits = new AtomicInteger(0);
	private AtomicInteger departureErrors = new AtomicInteger(0);
	private AtomicInteger timetableErrors = new AtomicInteger(0);
	
	private int old_stationLookupsLocation = 0;
	private int old_stationLookupsName = 0;
	private int old_stationLookupsFavorites = 0;
	private int old_departureLookups = 0;
	private int old_timetableLookups = 0;	
	private int old_departureCacheHits = 0;
	private int old_timetableCacheHits = 0;
	private int old_departureErrors = 0;
	private int old_timetableErrors = 0;
	
	private Date lastReset = new Date();
	
	public void incrementStationLookupsLocation() {
		stationLookupsLocation.incrementAndGet();
	}
	
	public void incrementStationLookupsName() {
		stationLookupsName.incrementAndGet();
	}
	
	public void incrementStationLookupsFavorites() {
		stationLookupsFavorites.incrementAndGet();
	}
	
	public void incrementDepartureLookups() {
		departureLookups.incrementAndGet();
	}
	
	public void incrementTimetableLookups() {
		timetableLookups.incrementAndGet();
	}
	
	public void incrementDepartureCacheHits() {
		departureCacheHits.incrementAndGet();
	}
	
	public void incrementTimetableCacheHits() {
		timetableCacheHits.incrementAndGet();
	}
	
	public void incrementDepartureErrors() {
		departureErrors.incrementAndGet();
	}
	
	public void incrementTimetableErrors() {
		timetableErrors.incrementAndGet();
	}
	
	/////////
	
	public int getStationTotals() {
		return stationLookupsLocation.get() + stationLookupsName.get() + stationLookupsFavorites.get();
	}
	
	public int getStationLookupsLocation() {
		return stationLookupsLocation.get();
	}
	
	public int getStationLookupsName() {
		return stationLookupsName.get();
	}
	
	public int getStationLookupsFavorites() {
		return stationLookupsFavorites.get();
	}
	
	public int getDepartureLookups() {
		return departureLookups.get();
	}
	
	public int getTimetableLookups() {
		return timetableLookups.get();
	}
	
	public int getDepartureCacheHits() {
		return departureCacheHits.get();
	}
	
	public int getTimetableCacheHits() {
		return timetableCacheHits.get();
	}
	
	public int getDepartureErrors() {
		return departureErrors.get();
	}
	
	public int getTimetableErrors() {
		return timetableErrors.get();
	}
	
	public Date getLastReset() {
		return lastReset;
	}
	
	
	/* helper functions */
	
	public String getElapsedAsString() {
		Date now = new Date();		
		long duration = (now.getTime() - lastReset.getTime() );
		
		return DurationFormatUtils.formatDuration(duration, "d, HH:mm:ss"); 
	}
	
	public double getElapsedDays() {
		Date now = new Date();		
		long elapsedMs = now.getTime() - lastReset.getTime();
		long elapsedHour = elapsedMs / (60*60*1000);
		
		double elapsedDay = ((double)elapsedHour) / 24.0;
		
		if (elapsedDay < 1.0)
			elapsedDay  = 1.0;
		
		return elapsedDay;
	}
	
	
	/*******
	 * Save stats to DB
	 */
	
	public void saveStats() {
		synchronized(this) {
			int loc = stationLookupsLocation.get();
			int name = stationLookupsName.get();
			int fav = stationLookupsFavorites.get();
			int departure = departureLookups.get();
			int depcache = departureCacheHits.get();
			int deperror = departureErrors.get();
			int timetable = timetableLookups.get();
			int timecache = timetableCacheHits.get();
			int timeerror = timetableErrors.get();
			
			int diff_loc = loc - old_stationLookupsLocation;
			int diff_name = name - old_stationLookupsName;
			int diff_fav = fav - old_stationLookupsFavorites;
			
			int diff_departure = departure - old_departureLookups;
			int diff_depcache = depcache - old_departureCacheHits;
			int diff_deperror = deperror - old_departureErrors;			
			
			int diff_timetable = timetable - old_timetableLookups;			
			int diff_timecache = timecache - old_timetableCacheHits;			
			int diff_timeerror = timeerror - old_timetableErrors;
			
			if ( diff_loc != 0 || diff_name != 0 || diff_fav != 0 ||
					diff_departure != 0 || diff_timetable != 0 || diff_depcache != 0 || diff_timecache != 0 ||
					diff_deperror != 0 || diff_timeerror != 0) {
				try {

					//System.out.println("Updating ...");
					Connection conn = DBConnection.getConnection();
					PreparedStatement stmt = conn.prepareStatement("UPDATE trainstatistics SET location=location+?, name=name+?, favorites=favorites+?, departure=departure+?, " + 
							"depcache=depcache+?, deperror=deperror+?, timetable=timetable+?, timecache=timecache+?, timeerror=timeerror+? " + 
							"WHERE statisticsdate=now()::date");
					
					stmt.setInt(1, diff_loc);
					stmt.setInt(2, diff_name);
					stmt.setInt(3, diff_fav);
					stmt.setInt(4, diff_departure);
					stmt.setInt(5, diff_depcache);
					stmt.setInt(6, diff_deperror);
					stmt.setInt(7, diff_timetable);
					stmt.setInt(8, diff_timecache);
					stmt.setInt(9, diff_timeerror);
					
					int rowcount = stmt.executeUpdate();
					
					stmt.close();
					
					if (rowcount == 0) {
						
						//System.out.println("inserting new row ...");
						stmt = conn.prepareStatement("INSERT INTO trainstatistics(statisticsdate,location,name,favorites,departure,depcache,deperror,timetable,timecache,timeerror) " +
								"values (now()::date, ?,?,?,?,?,?,?,?,?)" );
						
						stmt.setInt(1, diff_loc);
						stmt.setInt(2, diff_name);
						stmt.setInt(3, diff_fav);
						stmt.setInt(4, diff_departure);
						stmt.setInt(5, diff_depcache);
						stmt.setInt(6, diff_deperror);
						stmt.setInt(7, diff_timetable);
						stmt.setInt(8, diff_timecache);
						stmt.setInt(9, diff_timeerror);					
						
						stmt.executeUpdate();
					}
					
					
					old_stationLookupsLocation = loc;
					old_stationLookupsName = name;
					old_stationLookupsFavorites = fav;
					old_departureLookups = departure;
					old_departureCacheHits = depcache;	
					old_departureErrors = deperror;
					old_timetableLookups = timetable;	
					old_timetableCacheHits = timecache;
					old_timetableErrors = timeerror;
					
					conn.close();
					

				} catch (SQLException sqle) {
					
				}
			}
						
		}
	}
	
	/*******
	 * Singleton stuff
	 */
	
	private static Statistics instance = null;
	private Statistics() {
		// Exists only to defeat instantiation.
	}
	public static Statistics getInstance() {
		if(instance == null) {
			instance = new Statistics();
		}
		return instance;
	}
}