package inf101.v18.connectfour.board;

/**
 * An implementation of IGrid
 *
 * @param <T>   Can be anything
 */
public class Grid<T> implements IGrid<T> {
    private final T[][] grid;
    private final int width;
    private final int height;
    private final T empty;

    /**
     * Creates a new grid.
     *
     * @param width     The width of the new grid
     * @param height    The height of the new grid
     * @param object    The default object for all cells
     */@SuppressWarnings("unchecked")
    public Grid(int width, int height, T object) {
        if (!(width > 0 && height > 0)) {
            throw new IllegalArgumentException("Negative or zero height and/or width.");
        }
        if (object == null) {
            throw new IllegalArgumentException("Grid can't be initialized with null");
        }
        T[][] list = (T[][])new Object[width][height];
        for (int i = 0; i < width; i++) {
            for (int j = 0; j < height; j++) {
                list[i][j] = object;
            }
        }
        grid = list;
        this.empty = object;
        this.width = width;
        this.height = height;
    }

    @Override
    public void flush() {
        for (int i = 0; i < width; i++) {
            for (int j = 0; j < height; j++) {
                grid[i][j] = empty;
            }
        }
    }

    @Override
    public boolean isFull() {
        for (T[] list : grid) {
            for (T item : list) {
                if (this.empty.getClass().isInstance(item)) {
                    return false;
                }
            }
        }
        return true;
    }

    @Override
    public int getHeight() {
        return height;
    }

    @Override
    public int getWidth() {
        return width;
    }

    @Override
    public void set(int x, int y, T element) {
        if (x >= width || y >= height || x < 0 || y < 0) {
            throw new IllegalArgumentException("Index out of bounds.");
        }
        if (element == null) {
            throw new IllegalArgumentException("This grid does not accept null.");
        }
        grid[x][y] = element;
    }

    @Override
    public T get(int x, int y) {
        if (y >= height || x >= width || x < 0 || y < 0) {
            throw new IllegalArgumentException("Index out of bound.");
        }
        return grid[x][y];
    }

    @Override
    public IGrid<T> copy() {
        Grid<T> newGrid = new Grid<>(width, height, empty);
        for (int i = 0; i < width; i++) {
            System.arraycopy(grid[i], 0, newGrid.grid[i], 0, height);
        }
        return newGrid;
    }
}