package org.wamblee.gpx;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
import org.wamblee.general.Pair;
import org.wamblee.gps.geometry.Point;
import org.wamblee.gps.geometry.ReferenceCoordinateSystem;
import org.wamblee.gps.track.Track;

public class TrackStatistics {
    
    private Track _track; 
    
    public TrackStatistics(Track aTrack) {
        _track = aTrack; 
    }
    
    public void writeHeightProfileJpg(OutputStream aStream, int aWidth, int aHeight) throws IOException {
        List<Pair<Double,Double>> data = computeElevationProfile();
        XYSeriesCollection dataset = createDataset(data, "height");
        JFreeChart chart = ChartFactory.createXYLineChart(
                "Height Profile", 
                "Distance(km)",
                "Height(m)",
                dataset,
                PlotOrientation.VERTICAL,
                true,
                true,
                false);
        ChartUtilities.writeChartAsJPEG(aStream, chart, aWidth, aHeight);
    }
    
    private static XYSeriesCollection createDataset(List<Pair<Double, Double>> aHeightProfile, String aName) {
        XYSeries series = new XYSeries(aName, false);
        for (Pair<Double,Double> point: aHeightProfile) { 
            series.add(point.getFirst()/1000.0, point.getSecond());
        }
        XYSeriesCollection dataset = new XYSeriesCollection(series);
        return dataset;
    }
    
    public List<Pair<Double, Double>> computeElevationProfile() {
        List<Pair<Double,Double>> results = new ArrayList<Pair<Double,Double>>();
        double distance = 0.0; 
        for (int i = 0; i < _track.size(); i++) { 
            Point point = _track.getPoint(i);
            results.add(new Pair<Double,Double>(distance, point.getCoordinates().getX3()));
            if ( i+1 < _track.size()) { 
                Point nextPoint = _track.getPoint(i+1); 
                distance += ReferenceCoordinateSystem.distance(point, nextPoint);
            }
        }
        return results; 
    }
    
    public double getTotalClimb() {
        
        List<Pair<Double,Double>> data = computeElevationProfile(); 
        double result = 0.0;
        
        double lastHeight = data.get(0).getSecond();
        for ( int i = 1; i < data.size(); i++) { 
            double height = data.get(i).getSecond();
            if ( height > lastHeight) { 
                result += (height-lastHeight); 
            }
            lastHeight = height; 
        }
        return result; 
    }
    
    public double getDistance() { 
        List<Pair<Double,Double>> data = computeElevationProfile(); 
        return data.get(data.size()-1).getFirst();
    }
}