adding depth support

3 files changed, 23 insertions, 9 deletions

diff --git a/src/bot.cpp b/src/bot.cpp
index 4188308..916a311 100644
--- a/src/bot.cpp
+++ b/src/bot.cpp
@@ -10,8 +10,6 @@
 #include <iostream>
 #include <vector>
 
-const int SEARCH_DEPTH = 5;
-
 const int PAWN_VALUE = 100;
 const int KNIGHT_VALUE = 320;
 const int BISHOP_VALUE = 400;
@@ -127,7 +125,7 @@ std::vector<Move> GetSortedLegalMoves(Game *g) {
   return moves;
 }
 
-Move EngineGetBestMove(Game *b) {
+Move EngineGetBestMove(Game *b, int depth) {
   auto moves = GetSortedLegalMoves(b);
   if (moves.size() == 0) {
     std::cout << "Expected a position with legal moves";
@@ -142,7 +140,7 @@ Move EngineGetBestMove(Game *b) {
     float alpha = -INFINITY;
     float beta = INFINITY;
 
-    float eval = minimax(SEARCH_DEPTH - 1, b, alpha, beta);
+    float eval = minimax(depth - 1, b, alpha, beta);
 
     UnMakeMove(undo, b);
     if (b->turn) {
diff --git a/src/bot.hpp b/src/bot.hpp
index 26ae9f2..0ca0d05 100644
--- a/src/bot.hpp
+++ b/src/bot.hpp
@@ -3,7 +3,7 @@
 
 #include "board.hpp"
 #include <vector>
-Move EngineGetBestMove(Game *b);
+Move EngineGetBestMove(Game *b, int depth);
 float EvaluateBoardForWhite(Game *b, int depth);
 float minimax(int depth, Game *b, float alpha, float beta);
 int ScoreMove(const Game *board, const Move &move);
diff --git a/src/uci.cpp b/src/uci.cpp
index 8a7ad9a..e6aec4e 100644
--- a/src/uci.cpp
+++ b/src/uci.cpp
@@ -9,7 +9,6 @@
 #include <cctype>
 #include <cstdint>
 #include <iostream>
-#include <print>
 #include <sstream>
 #include <string>
 
@@ -126,11 +125,27 @@ void Uci() {
       cout << "readyok\n";
       cout.flush();
     } else if (cmd.starts_with("go")) {
-      Move best = EngineGetBestMove(&game);
+
+      stringstream ss(line);
+
+      string token;
+      int depth = 4; // default depth
+
+      ss >> token; // go
+
+      while (ss >> token) {
+        if (token == "depth") {
+          ss >> depth;
+          break;
+        }
+      }
+
+      Move best = EngineGetBestMove(&game, depth);
 
       cout << "bestmove ";
       cout << (char)(best.From.file + 'a') << 8 - best.From.rank
            << (char)(best.To.file + 'a') << 8 - best.To.rank;
+
       if (best.promotion != NONEPIECE) {
         switch (best.promotion) {
         case QUEEN:
@@ -146,10 +161,11 @@ void Uci() {
           cout << "b";
           break;
         default:
-          assert(false && "Unexepted promotion type");
+          assert(false && "Unexpected promotion type");
         }
       }
-      println();
+
+      cout << "\n";
       SaveTranspositionTable(transpositions);
       cout.flush();
     } else if (cmd.starts_with("position")) {