Map.java

package com.bootcamp.battleship;

import java.util.Arrays;

public class Map {
    private String[][] map;
    private int grid;

    public Map(int grid) {
        int minArray = 1;

        if (grid < minArray) {
            throw new IllegalArgumentException("Grid must larger than 0");
        }

        this.grid = grid;
        fill();
    }

    public String get(Coordinate coordinate) {
        checkCoordinate(coordinate);

        int xAxis = coordinate.getXAxis();
        int yAxis = coordinate.getYAxis();

        return this.map[xAxis][yAxis];
    }

    public void change(Coordinate coordinate, String withValue) {
        checkCoordinate(coordinate);

        int xAxis = coordinate.getXAxis();
        int yAxis = coordinate.getYAxis();

        this.map[xAxis][yAxis] = withValue;
    }

    public int count(String countValue) {
        int count = 0;

        for(String[] line: this.map) {
            for(String value: line) {
                if (value.equals(countValue)) {
                    count += 1;
                }
            }
        }

        return count;
    }

    private void fill() {
        this.map = new String[this.grid][this.grid];

        for (String[] line: this.map) {
            Arrays.fill(line, "_");
        }
    }
    private void checkCoordinate(Coordinate coordinate) {
        int xAxis = coordinate.getXAxis();
        int yAxis = coordinate.getYAxis();

        if (xAxis < 0 || yAxis < 0) {
            throw new IllegalArgumentException("Coordinate should not negative");
        }
    }
}