package com.Lab1;

public class Matrix {
    double[]data;
    int rows;
    int cols;

    Matrix(int rows, int cols){
        this.rows = rows;
        this.cols = cols;
        data = new double[rows*cols];
        this.fill(0);
    }

    // 2.1
    Matrix(double[][] d) {
        int longest = 0;
        for(int i = 0; i < d.length; i++){
            if (d[i].length > longest){
                longest = d[i].length;
            }
        }
        this.rows = d.length;
        this.cols = longest;
        data = new double[rows*cols];

        for(int i =0; i < d.length ; i++){
            int j = 0;
            while(j < d[i].length){
                data[i * cols + j] = d[i][j];
                j++;
            }
            while(j < cols){
                data[i * cols + j] = 0;
                j++;
            }
        }
    }

    // fill method:
    private void fill(double value){
        for(int i=0;i<this.rows;i++){
            for(int j=0;j<this.cols;j++){
                this.set(i,j,value);
            }
        }
    }

    // 2.2
    public double[][] asArray(){
        double[][] result = new double[rows][cols];
        for(int i=0; i< rows;i++) {
            for (int j = 0; j < cols; j++) {
                result[i][j] = data[i*cols + j];
            }
        }
        return result;
    }

    // 2.3
    public double get(int r,int c){
        // + try/except clausure
        return data[r * cols + c];
    }

    public void set (int r,int c, double value){
        data[r * cols + c] = value;
    }

    // 2.4
    public String toString(){
        StringBuilder buf = new StringBuilder();
        buf.append("[\n");
        for(int i=0;i<rows;i++){
            buf.append("  [ ");
            for(int j=0;j<cols;j++){
                buf.append(data[i * cols + j]);
                buf.append(" ");
            }
            buf.append("]\n");
        }
        buf.append("]");
        return buf.toString();
    }

    // 2.5
    public void reshape(int newRows,int newCols){
        if(rows*cols != newRows*newCols)
            throw new RuntimeException(String.format("%d x %d matrix can't be reshaped to %d x %d",rows,cols,newRows,newCols));
        this.rows = newRows;
        this.cols = newCols;
    }

    // 2.6
    public int[] shape(){
        int[] result = new int[]{this.rows,this.cols};
        return result;
    }

    // 2.7 & 2.8
    // add:
    public Matrix add(Matrix other){
        if (this.rows != other.shape()[0] || this.cols != other.shape()[1]){
            throw new RuntimeException("ERROR");
        }

        Matrix result = new Matrix(this.rows,this.cols);
        for(int i=0;i<this.rows;i++){
            for(int j=0;j<this.cols;j++){
                result.set(i,j,this.get(i,j) + other.get(i,j));
            }
        }
        return result;
    }

    public Matrix add(double w) {
        Matrix result = new Matrix(this.rows,this.cols);
        for(int i=0;i<this.rows;i++){
            for(int j=0;j<this.cols;j++){
                result.set(i,j,this.get(i,j) + w);
            }
        }
        return result;
    }

    // substitution:
    public Matrix sub(Matrix other){
        if (this.rows != other.shape()[0] || this.cols != other.shape()[1]){
            throw new RuntimeException("ERROR");
        }

        Matrix result = new Matrix(this.rows,this.cols);
        for(int i=0;i<this.rows;i++){
            for(int j=0;j<this.cols;j++){
                result.set(i,j,this.get(i,j) - other.get(i,j));
            }
        }
        return result;
    }

    public Matrix sub(double w) {
        Matrix result = new Matrix(this.rows,this.cols);
        for(int i=0;i<this.rows;i++){
            for(int j=0;j<this.cols;j++){
                result.set(i,j,this.get(i,j) - w);
            }
        }
        return result;
    }

    // multiplication:
    public Matrix mul(Matrix other){
        if (this.rows != other.shape()[0] || this.cols != other.shape()[1]){
            throw new RuntimeException("ERROR");
        }

        Matrix result = new Matrix(this.rows,this.cols);
        for(int i=0;i<this.rows;i++){
            for(int j=0;j<this.cols;j++){
                result.set(i,j,this.get(i,j) * other.get(i,j));
            }
        }
        return result;
    }

    public Matrix mul(double w){
        Matrix result = new Matrix(this.rows,this.cols);
        for(int i=0;i<this.rows;i++){
            for(int j=0;j<this.cols;j++){
                result.set(i,j,this.get(i,j) * w);
            }
        }
        return result;
    }

    // division:
    public Matrix div(Matrix other){
        if (this.rows != other.shape()[0] || this.cols != other.shape()[1]){
            throw new RuntimeException("ERROR");
        }

        Matrix result = new Matrix(this.rows,this.cols);
        for(int i=0;i<this.rows;i++){
            for(int j=0;j<this.cols;j++){
                result.set(i,j,this.get(i,j) / other.get(i,j));
            }
        }
        return result;
    }

    public Matrix div(double w){
        Matrix result = new Matrix(this.rows,this.cols);
        for(int i=0;i<this.rows;i++){
            for(int j=0;j<this.cols;j++){
                result.set(i,j,this.get(i,j) / w);
            }
        }
        return result;
    }

    // matrix multiplication
//    public Matrix dot(Matrix other){
//        if (this.cols != other.shape()[0]){
//            throw new RuntimeException("ERROR");
//        }
//
//        Matrix result = new Matrix(this.rows, other.shape()[1]);
//        result.fill(0);
//
//        for(int i=0;i<this.cols;i++){
//            for(int j=0;j<this.cols()[0]){
//
//            }
//        }
//
//    }



}