Make apply_move accept a board as a parameter.

This was how it originally was, but I changed it to use a global
variable instead. I want to be able to use the apply_move function in
the is_valid_move implementation, to have all the logic for checking if
a move is valid in one place.

Moved the apply_move function out of board.c, since it no longer
needs a direct reference to the board.

1 files changed, 105 insertions, 11 deletions

diff --git a/src/move.c b/src/move.c
index a22cb59..968dcfa 100644
--- a/src/move.c
+++ b/src/move.c
@@ -53,10 +53,10 @@ static char *prompt_player(enum player_color current_player) {
   }
 }
 
-static void inner_main(void *closure, int argc, char **argv) {
-  (void)closure;
-  scm_shell(argc, argv);
-}
+/*static void inner_main(void *closure, int argc, char **argv) {*/
+  /*(void)closure;*/
+  /*scm_shell(argc, argv);*/
+/*}*/
 
 struct move prompt_get_move(enum player_color current_player) {
   // Initialize move to an invalid move.
@@ -72,13 +72,13 @@ struct move prompt_get_move(enum player_color current_player) {
         print_help();
       } else if (STREQ(input, "p")) {
         print_board();
-      } else if (STREQ(input, "g")) {
-        int argc = 1;
-        char **argv = calloc(1, sizeof(char *));
-        argv[0] = "othello";
-        /*scm_with_guile(void *(*func)(void *), void *data)*/
-        scm_boot_guile(argc, argv, inner_main, NULL);
-        free(argv);
+      /*} else if (STREQ(input, "g")) {*/
+        /*int argc = 1;*/
+        /*char **argv = calloc(1, sizeof(char *));*/
+        /*argv[0] = "othello";*/
+        /*[>scm_with_guile(void *(*func)(void *), void *data)<]*/
+        /*scm_boot_guile(argc, argv, inner_main, NULL);*/
+        /*free(argv);*/
       } else {
         sscanf(input, "%d %d", &move.row, &move.col);
       }
@@ -93,3 +93,97 @@ struct move prompt_get_move(enum player_color current_player) {
 
   return move;
 }
+
+/* Returns true if the move was valid */
+bool apply_move(enum player_color **board, enum player_color current_player, struct move move) {
+
+  // The move must be a positive position.
+  if (move.row < 0 || move.col < 0) {
+    return false;
+  }
+
+  // The move must be below the upper bounds of teh board.
+  if (move.row > 8 || move.col > 8) {
+    return false;
+  }
+
+  // The move must be an empty spot.
+  if (board[move.row][move.col] != EMPTY) {
+    return false;
+  }
+
+  // Flip in up direction
+  bool flipped_up = false;
+  for (int i = move.row - 1;
+       i > 0 && board[i][move.col] != EMPTY && !flipped_up; i--) {
+    if (board[i][move.col] == current_player) {
+      if (i < move.row - 1) {
+        for (int j = move.row; j > i; j--) {
+          board[j][move.col] = current_player;
+        }
+        flipped_up = true;
+      } else {
+        break;
+      }
+    }
+  }
+
+  // Flip in down direction
+  bool flipped_down = false;
+  for (int i = move.row + 1;
+       i < 8 && board[i][move.col] != EMPTY && !flipped_down; i++) {
+    if (board[i][move.col] == current_player) {
+      if (i > move.row + 1) {
+        for (int j = move.row; j < i; j++) {
+          board[j][move.col] = current_player;
+        }
+        flipped_down = true;
+      } else {
+        break;
+      }
+    }
+  }
+
+  // Flip in left direction
+  bool flipped_left = false;
+  for (int i = move.col - 1;
+       i > 0 && board[move.row][i] != EMPTY && !flipped_left; i--) {
+    if (board[move.row][i] == current_player) {
+      if (i < move.col - 1) {
+        for (int j = move.col; j > i; j--) {
+          board[move.row][j] = current_player;
+        }
+        flipped_left = true;
+      } else {
+        break;
+      }
+    }
+  }
+
+  // Flip in right direction
+  bool flipped_right = false;
+  for (int i = move.col + 1;
+       i < 8 && board[move.row][i] != EMPTY && !flipped_right; i++) {
+    if (board[move.row][i] == current_player) {
+      if (i > move.col + 1) {
+        for (int j = move.col; j < i; j++) {
+          board[move.row][j] = current_player;
+        }
+        flipped_right = true;
+      } else {
+        break;
+      }
+    }
+  }
+
+  return flipped_up || flipped_down || flipped_left || flipped_right;
+}
+
+struct move get_scm_move(FILE *strategy) {
+  // Initialize move to an invalid move.
+  struct move move = {-1, -1};
+  return move;
+  (void)strategy;
+}
+
+