/*----------------------------------------------------------
 *				HTBLA-Leonding / Class: 2IHIF
 * ---------------------------------------------------------
 * Exercise Number: B1
 * Title:			Mine Sweeper Board implementation
 * Author:			Marc Tismonar
 * ----------------------------------------------------------
 * Description:
 * Implementation of ms_board.h.
 * ----------------------------------------------------------
 */

#include "ms_board.h"

#include "config.h"
#include <stdlib.h>

struct MsBoardData {
    Count column_count;
    Count row_count;
    MsCell cells[MAX_BOARD_SIZE][MAX_BOARD_SIZE];
};

static MsBoard the_board = 0;

/**
 * Provides the instance of the 'Mine Sweeper' board.
 * Exactly one instance is supported. The board state
 * is not affected by this function.
 * 
 * @return The board instance.
 */
MsBoard msb_get_board() {
    if (the_board == 0) {
        the_board = (MsBoard)calloc(1, sizeof(struct MsBoardData));
    }
    return the_board;
}

/**
 * Initializes the only Mine Sweeper board:
 * + Defines the actual size of the board (columns and rows) up to the configured values.
 * + Initializes all cells as 'empty' and 'covered'.
 * The number of columns and rows shall be clipped to MAX_BOARD_SIZE.
 * 
 * @param board The board instance in focus.
 * @param column_count The number of cell columns of the board.
 * @param row_count  The number of cell row of the board.
 */
void msb_init_board(MsBoard board, Count column_count, Count row_count) {
    if (board == 0) {
        return;
    }

    board->column_count = column_count > MAX_BOARD_SIZE ? MAX_BOARD_SIZE : column_count;
    board->row_count = row_count > MAX_BOARD_SIZE ? MAX_BOARD_SIZE : row_count;

    msc_reset_cell_factory();

    for (int row = 0; row < board->row_count; row++) {
        for (int col = 0; col < board->column_count; col++) {
            board->cells[col][row] = msc_produce_cell();
        }
    }
}

/**
 * Determines whether or not the given board is valid.
 * A board is NOT valid
 *      + if it is 0,
 *      + or if it has a size of 0 (0 columns or 0 rows).
 * 
 * @param board The board instance in focus.
 * @return True if the given board is valid, false otherwise.
 */
bool msb_is_valid(MsBoard board) {
    return board != 0 && board->column_count > 0 && board->row_count > 0;
}

/**
 * Provides the cell at the given coordinates.
 * 
 * @param board The board instance in focus.
 * @param col_idx The index of the column of the addressed cell.
 * @param row_idx The index of the row of the addressed cell.
 * @return The addressed cell or 0, if the coordinates are not in range.
 */
MsCell msb_get_cell(MsBoard board, CellIdx col_idx, CellIdx row_idx) {
    if (!msb_is_valid(board) || col_idx >= board->column_count || row_idx >= board->row_count) {
        return 0;
    }

    return board->cells[col_idx][row_idx];
}

/**
 * Provides the number of columns used by the current game (of the 'active' area).
 * 
 * @param board The board instance in focus.
 * @return The number of columns used for the current board configuration or 0,
 * if the board is not configured or invalid.
 */
Count msb_get_column_count(MsBoard board) {
    return msb_is_valid(board) ? board->column_count : 0;
}

/**
 * Provides the number of rows used by the current game (of the 'active' area).
 * 
 * @param board The board instance in focus.
 * @return The number of columns used for the current board configuration or 0,
 * if the board is not configured or invalid.
 */
Count msb_get_row_count(MsBoard board) {
    return msb_is_valid(board) ? board->row_count : 0;
}