/**
 * Class for playing with Lights Out puzzles.
 */
public class LightsOutGame {

    /** Default number of rows in a puzzle. */
    public static final int DEFAULT_ROWS = 5;

    /** Default number of columns in a puzzle. */
    public static final int DEFAULT_COLS = 5;

    /** Character for light on in string representation. */
    public static final char LIGHT_ON = '*';

    /** Character for light off in string representation. */
    public static final char LIGHT_OFF = '-';

    /**
     * Create a lights out puzzle grid of given dimensions with all lights off.
     * @param rows Number of rows
     * @param cols Number of columns
     * @return 2D array of booleans with all values set to false.
     */
    public static boolean[][] createEmptyPuzzle(int rows, int cols) {
        // TODO: implement this
        return null;
    }

    /**
     * Given a 2D array of booleans, how many rows does it have?
     * @param arr The array in question
     * @return The number of rows in the array.
     */
    public static int numRows(boolean[][] arr) {
        // TODO: implement this
        return -1;
    }

    /**
     * Given a 2D array of booleans, how many columns does it have?
     * @param arr The array in question
     * @return The number of columns in the array.
     */
    public static int numCols(boolean[][] arr) {
        // TODO: implement this
        return -1;
    }

    /**
     * Creates a string representation of the game board.
     * Rows end with a newline character.
     * @param grid The grid of lights
     * @return String representation of the board
     */
    public static String gridToString(boolean[][] grid) {
        // TODO: implement this
        return null;
    }

    /**
     * Is this puzzle solved?
     * In other words, are all the lights off?
     * @param puzzle The puzzle grid
     * @return True if all lights are off, false if any are on.
     */
    public static boolean isPuzzleSolved(boolean[][] puzzle) {
        // TODO: implement this
        return false;
    }

    /**
     * Toggle the status of a single light, if possible.
     *
     * @param row  The row of the light location
     * @param col  The column of the light location
     * @param grid The game board
     * @return Turns light at location on if it was off and off it was on and
     *         returns true. Returns false without changing the board if the
     *         location was invalid.
     */
    public static boolean toggleSingleLight(int row, int col, boolean[][] grid) {
        // TODO: implement this
        return false;
    }

    /**
     * Toggle the status of a light and its neighbors, if possible, and
     * return how many lights were toggled.
     *
     * @param row  The row of the light location
     * @param col  The column of the light location
     * @param puzzle The game board
     * @return Toggles on/off status of light and its vertical and horizontal
     *         neighbors and returns number of lights toggled. Returns 0 without
     *         changing the board if the location was invalid.
     */
    public static int toggleLightWithNeighbors(int row, int col, boolean[][] puzzle) {
        // TODO: implement this using toggleSingleLight
        return -1;
    }

    /**
     * Selects a random location on the board and toggles it with its neighbors.
     * @param board The game board.
     * @return Number of lights toggled
     */
    public static int toggleRandomLocationWithNeighbors(boolean[][] board) {
        // TODO: implement this using toggleLightWithNeighbors
        return -42;
    }

    /**
     * Create a random solvable puzzle of desired size.
     *
     * To make a solvable puzzle, turn on lights by toggling a random location
     * with its neighbors. (The solution will be to toggle those same positions.)
     * Toggle roughly half the locations. (It's okay if you toggle the same place
     * more than once, undoing your earlier random toggle.)
     *
     * @param rows Number of rows
     * @param cols Number of columns
     * @return Game board with some lights turned on.
     */
    public static boolean[][] createRandomPuzzle(int rows, int cols) {
        // TODO: implement this using toggleRandomLocationWithNeighbors
        return null;
    }

    /** Creates puzzle array and starts game GUI. */
    public static void main(String[] args) {
        boolean[][] b = createRandomPuzzle(DEFAULT_ROWS, DEFAULT_COLS);
        LightsOutGUI.showGUI(b);
    }
}