feat: dont allow castle under check

1 files changed, 29 insertions, 14 deletions

diff --git a/src/main.c b/src/main.c
index e25d6e2..5107338 100644
--- a/src/main.c
+++ b/src/main.c
@@ -158,6 +158,8 @@ Move input_move() {
   return move;
 };
 
+int list_moves_with_destination(Move* moves, int* board, int color, int destination);
+
 int validate_move(Move move, int color, int* board) {
   // Null move means player is checkmated
   if (move.origin == -100 && move.destination == -100) return INFINITY;
@@ -224,25 +226,29 @@ int validate_move(Move move, int color, int* board) {
   if ((piece & NO_COLOR) == KING) {
     if (piece % 2 == WHITE && move.origin == 4) {
       if (move.destination == 2) {
+        if (list_moves_with_destination(NULL, board, color ^ 1, move.origin)) return -5;
         for (int i = 1; i < 4; i++) {
-          if (board[i] != EMPTY) return -5;
+          if (board[i] != EMPTY || list_moves_with_destination(NULL, board, color ^ 1, i)) return -5;
         }
         return 0;
       } else if (move.destination == 6) {
+        if (list_moves_with_destination(NULL, board, color ^ 1, move.origin)) return -5;
         for (int i = 5; i < 7; i++) {
-          if (board[i] != EMPTY) return -5;
+          if (board[i] != EMPTY || list_moves_with_destination(NULL, board, color ^ 1, i)) return -5;
         }
         return 0;
       }
     } else if (piece % 2 == BLACK && move.origin == 116) {
       if (move.destination == 114) {
+        if (list_moves_with_destination(NULL, board, color ^ 1, move.origin)) return -5;
         for (int i = 114; i < 116; i++) {
-          if (board[i] != EMPTY) return -5;
+          if (board[i] != EMPTY || list_moves_with_destination(NULL, board, color ^ 1, i)) return -5;
         }
         return 0;
       } else if (move.destination == 118) {
+        if (list_moves_with_destination(NULL, board, color ^ 1, move.origin)) return -5;
         for (int i = 117; i < 119; i++) {
-          if (board[i] != EMPTY) return -5;
+          if (board[i] != EMPTY || list_moves_with_destination(NULL, board, color ^ 1, i)) return -5;
         }
         return 0;
       }
@@ -407,7 +413,7 @@ int compute_material_advantage(int* board, int color) {
   return counter;
 }
 
-int list_available_moves(Move* moves, int* board, int color) {
+int list_moves_with_destination(Move* moves, int* board, int color, int destination) {
   int moves_count = 0;
 
   for (int rank = 7; rank >= 0; rank--) {
@@ -415,15 +421,10 @@ int list_available_moves(Move* moves, int* board, int color) {
       int index = rank * 16 + file;
       int piece = board[index];
       if (piece != EMPTY && (piece % 2) == color) {
-        for (int rank_destination = 7; rank_destination >= 0; rank_destination--) {
-          for (int file_destination = 0; file_destination < 8; file_destination++) {
-            int index_destination = rank_destination * 16 + file_destination;
-            Move move = { index, index_destination, 0 };
-            if (validate_move(move, color, board) >= 0) {
-              if (moves) moves[moves_count] = move;
-              moves_count++;
-            }
-          }
+        Move move = { index, destination, 0 };
+        if (validate_move(move, color, board) >= 0) {
+          if (moves) moves[moves_count] = move;
+          moves_count++;
         }
       }
     }
@@ -432,6 +433,20 @@ int list_available_moves(Move* moves, int* board, int color) {
   return moves_count;
 }
 
+int list_available_moves(Move* moves, int* board, int color) {
+  int moves_count = 0;
+
+  for (int rank = 7; rank >= 0; rank--) {
+    for (int file = 0; file < 8; file++) {
+      int destination = rank * 16 + file;
+      Move* next_ptr = moves ? moves + moves_count : NULL;
+      moves_count += list_moves_with_destination(next_ptr, board, color, destination);
+    }
+  }
+
+  return moves_count;
+}
+
 // Count doubled, blocked and isolated pawns
 int count_bad_pawns(int* board, int color) {
   int bad_pawns = 0;