package learningjava;

import java.util.ArrayList;

public class SMatrix {

    private int order;
    private double[][] values;
    private static double[][] def = { { 0 } };

    public SMatrix(int order, double[][] values) {
        this.order = order;
        this.values = values;
    }

    public SMatrix() {
        this(1, def);
    }

    public SMatrix(SMatrix m) {
        this(m.order, m.values);
    }

    public int getOrder() {
        return this.order;
    }

    public void setOrder(int order) {
        this.order = order;
    }

    public void multiplyRow(int row, int c) {
        for (int i = 0; i < order; i++) {
            this.values[row - 1][i] *= c;
        }
    }

    public void addRows(int row1, int row2) {
        for (int i = 0; i < order; i++) {
            this.values[row2 - 1][i] += this.values[row1 - 1][i];
        }
    }

    public void switchRow(int row1, int row2) {
        double[] temp = new double[order];
        for (int i = 0; i < order; i++) {
            temp[i] = this.values[row1 - 1][i];
            this.values[row1 - 1][i] = this.values[row2 - 1][i];
            this.values[row2 - 1][i] = temp[i];
        }
    }

    public static SMatrix addMatrix(SMatrix m1, SMatrix m2) {
        double[][] temp = new double[m1.order][m1.order];
        SMatrix m;
        if (m1.order != m2.order) {
            System.out.println("the 2 matrices have to be of the same order");
            return new SMatrix();
        } else {
            for (int i = 0; i < m1.order; i++) {
                for (int j = 0; j < m1.order; j++) {
                    temp[i][j] = m1.values[i][j] + m2.values[i][j];
                }
            }
            m = new SMatrix(m1.order, temp);
            return m;
        }

    }

    public static SMatrix multiplyMatrix(SMatrix m1, SMatrix m2) {
        double[][] temp = new double[m1.order][m1.order];
        double sum = 0;
        int c = 0, d = 0;

        ArrayList<Double> row = new ArrayList<Double>();
        for (int k = 0; k < m1.order; k++) {
            for (int i = 0; i < m1.order; i++) {
                for (int j = 0; j < m1.order; j++) {

                    sum += m1.values[d][j] * m2.values[j][i];

                }

                row.add(sum);
                sum = 0;
            }
            d++;
        }

        for (int i = 0; i < temp.length; i++) {

            for (int j = 0; j < temp.length; j++) {

                temp[i][j] = row.get(c++);
            }

        }
        return new SMatrix(m1.order, temp);

    }

    public static SMatrix getIdentity(SMatrix m) {
        double[][] identity = new double[m.order][m.order];
        for (int i = 0; i < m.order; i++) {
            for (int j = 0; j < m.order; j++) {
                if (i == j)
                    identity[i][i] = 1;
                else
                    identity[i][j] = 0;
            }
        }
        return new SMatrix(m.order, identity);
    }

    public String toString() {
        String s = "";
        for (int i = 0; i < order; i++) {
            for (int j = 0; j < order; j++) {

                s += values[i][j] + "\t";
                if (j == order - 1) {
                    s += "\n\n";

                }
            }

        }
        return s;
    }

    public static void main(String[] args) {

        double[][] test = { { 1, 2, 3 }, { 3, 4, 5 }, { 5, 6, 7 } };
        double[][] test2 = { { 2, 2, 5 }, { 1, 7, 5 }, { 5, 6, 7 } };

        SMatrix m = new SMatrix(3, test);
        SMatrix m2 = new SMatrix(3, test2);
        System.out.println(m.toString());
        System.out.println(m2.toString());

        m.multiplyRow(2, 2);
        System.out.println(m.toString());

        m.addRows(1, 2);
        System.out.println(m.toString());

        m.switchRow(1, 2);
        System.out.println(m.toString());

        System.out.println(m2.toString());
        System.out.println(addMatrix(m, m2).toString());
        System.out.println(getIdentity(m).toString());
        System.out.println(multiplyMatrix(m, m2));

    }

}