* =====================================================================================
*/
+#include <stdlib.h>
+#include <stdbool.h>
+#include "othello.h"
+
+unsigned int current_player(unsigned int round_count) {
+
+ if (round_count % 2 != 0) {
+ return player_two;
+ } else {
+ return player_one;
+ }
+}
+
+/* for consitency with ncurses, the board coordinates are in the following order:
+ * O--x-->
+ * |
+ * y
+ * |
+ * v
+ * The origin O has (1, 1) coordinates */
+
+unsigned int get_box_value(int y, int x, unsigned int pawn_array[board_size][board_size]) {
+
+ return pawn_array[y-1][x-1];
+}
+
+bool is_box_type(int y, int x, unsigned int pawn_array[board_size][board_size], unsigned int type) {
+
+ if (type > 2) {
+ return NULL;
+ }
+ if (get_box_value(y, x, pawn_array) == type) {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+/* helper function to set a value != empty at the (y, x) coordinates in the pawns array */
+int** set_pawn(int y, int x, unsigned int type, unsigned int pawn_array[board_size][board_size]) {
+
+ if (is_box_type(y, x, pawn_array, empty)) {
+ pawn_array[y-1][x-1] = type;
+ return (int**)pawn_array;
+ } else {
+ return NULL;
+ }
+}
+
+static int** zero_pawns(unsigned int pawn_array[board_size][board_size]) {
+
+ for (unsigned int i = 1; i <= board_size; i++) {
+ for (unsigned int j = 1; j <= board_size; j++) {
+ pawn_array = set_pawn(i, j, empty, pawn_array);
+ }
+ }
+ return (int**)pawn_array;
+}
+
+/* set the pawns in the start position */
+int** init_pawns(unsigned int pawn_array[board_size][board_size]) {
+
+ pawn_array = zero_pawns(pawn_array);
+ pawn_array = set_pawn(5, 4, black, pawn_array);
+ pawn_array = set_pawn(4, 5, black, pawn_array);
+ pawn_array = set_pawn(4, 4, white, pawn_array);
+ pawn_array = set_pawn(5, 5, white, pawn_array);
+ return (int**)pawn_array;
+}
+
+unsigned int count_pawn_type(unsigned int pawn_array[board_size][board_size], unsigned int type) {
+ unsigned int count = 0;
+
+ if (type > 2) {
+ return -1;
+ }
+ for (unsigned int i = 1; i <= board_size; i++) {
+ for (unsigned int j = 1; j <= board_size; j++) {
+ if (is_box_type(i, j, pawn_array, type)) {
+ count++;
+ }
+ }
+ }
+ return count;
+}
+
+bool is_valid_input(int y, int x, unsigned int pawn_array[board_size][board_size]) {
+
+ /* FIXME: separate the tests to permit to print explicit error messages */
+ if ((y > 0 && y < board_size + 1) && \
+ (x > 0 && x < board_size + 1) && \
+ is_box_type(y, x, pawn_array, empty)) {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+bool is_board_full(unsigned int pawn_array[board_size][board_size]) {
+
+ /* an alternate method is to test the round count vs. 60 */
+ for (unsigned int i = 1; i <= board_size; i++) {
+ for (unsigned int j = 1; j <= board_size; j++) {
+ if (is_box_type(i, j, pawn_array , empty)) {
+ return false;
+ }
+ }
+ }
+ return true;
+}
+
+unsigned int eval_winner(unsigned int nb_white, unsigned int nb_black) {
+
+ if (nb_white > nb_black) {
+ return player_two;
+ } else if (nb_white < nb_black) {
+ return player_one;
+ } else {
+ return 0;
+ }
+}
+
+void direction_to_coordinates(unsigned int direction, int* start_y, int* start_x) {
+
+ if (direction == north) {
+ *start_y = *start_y - 1;
+ } else if (direction == north_east) {
+ *start_y = *start_y - 1;
+ *start_x = *start_x + 1;
+ } else if (direction == east) {
+ *start_x = *start_x + 1;
+ } else if (direction == south_east) {
+ *start_y = *start_y + 1;
+ *start_x = *start_x + 1;
+ } else if (direction == south) {
+ *start_y = *start_y + 1;
+ } else if (direction == south_west) {
+ *start_y = *start_y + 1;
+ *start_x = *start_x - 1;
+ } else if (direction == west) {
+ *start_x = *start_x - 1;
+ } else if (direction == north_west) {
+ *start_y = *start_y - 1;
+ *start_x = *start_x - 1;
+ }
+}
+
+bool explore(int y, int x, int direction) {
+
+}