import java.util.ArrayList;

public class KMeans extends VarMin{
    public KMeans(int k){
        super(k);
    }

    @Override
    public void clustering(){
        initCluster();
        System.out.println(getCompactness());
        boolean change = true;
        while(change){
            change = false;
            for(int i = 0; i < data.size();i++) {
                int newCluster = getClosestCluster(data.get(i));
                int oldCluster = clusterMap.get(i);
                if(oldCluster != newCluster){
                    clusterMap.set(i, newCluster);

                    //update centroids
                    ArrayList<Double> p = new ArrayList<>(data.get(i));
                    ArrayList<Double> u1 = new ArrayList<>(centroids.get(oldCluster));
                    ArrayList<Double> u2 = new ArrayList<>(centroids.get(newCluster));
                    mulPoint(u1, (double)count[oldCluster]);
                    mulPoint(u2, (double)count[newCluster]);

                    addPoint(u2, p);
                    mulPoint(p, -1.0);
                    addPoint(u1, p);

                    mulPoint(u1,(1.0 / (count[oldCluster] - 1)));
                    mulPoint(u2,(1.0 / (count[newCluster] + 1)));
                    centroids.set(oldCluster, u1);
                    centroids.set(newCluster, u2);

                    count[oldCluster]--;
                    count[newCluster]++;

                    //centroids.get(oldCluster) = (1.0 / (count[oldCluster] - 1)) * (count[oldCluster] * centroids.get(oldCluster) - data.get(i));
                    //centroids.get(newCluster) = (1.0 / (count[newCluster] + 1)) * (count[newCluster] * centroids.get(newCluster) + data.get(i));

                    //calcCluster();
                    change = true;
                }
            }
            System.out.println(getCompactness());
        }
    }

    public static void main(String[] args) {
        int k = 3;
        if(args.length >= 1){
            k = Integer.parseInt(args[0]);
        }
        KMeans kmeans = new KMeans(k);
        ArrayList<ArrayList<Double>> data = DataFileReader.readFile("input.txt");
        kmeans.setData(data);

        kmeans.clustering();
        ArrayList<ArrayList<ArrayList<Double>>> cluster1 = kmeans.getCluster();
        System.out.println("Result:");
        printCluster(cluster1);

        writeToFile(cluster1, "cluster.txt");
    }
}