1 files changed, 247 insertions, 0 deletions
diff --git a/src/board/board.cpp b/src/board/board.cpp
new file mode 100644
index 0000000..a76ec42
--- /dev/null
+++ b/src/board/board.cpp
@@ -0,0 +1,247 @@
+#include "board.hpp"
+#include "../moves.hpp"
+#include "zobrist/zobrist.hpp"
+#include <cassert>
+
+Piece createPiece(PieceType type, bool color) {
+  Piece piece;
+  piece.type = type;
+  piece.color = color;
+  return piece;
+}
+
+int PositionToIndex(Position i) { return i.rank * 8 + i.file; }
+
+Position FindKing(Game *b, bool white) {
+  for (int i = 0; i < 64; i++) {
+    Piece piece = b->pieces[i];
+
+    if (piece.type == KING && piece.color == white) {
+      return IndexToPosition(i);
+    }
+  }
+
+  assert(false && "King not found");
+  return {0, 0};
+}
+UndoMove MakeMove(Move move, Game *g) {
+  UndoMove undo = {};
+
+  undo.from = move.From;
+  undo.to = move.To;
+
+  undo.movedPiece = g->pieces[PositionToIndex(move.From)];
+  undo.capturedPiece = g->pieces[PositionToIndex(move.To)];
+
+  undo.oldTurn = g->turn;
+  undo.oldCanEnpassant = g->canEnpassant;
+  undo.oldEnPassant = g->enPassant;
+
+  undo.oldHalfMoveClock = g->halfMoveClock;
+  undo.oldMoveClock = g->MoveClock;
+
+  undo.oldState = g->state;
+
+  undo.OldwhiteCastleKing = g->whiteCastleKing;
+  undo.OldwhiteCastleQueen = g->whiteCastleQueen;
+  undo.OldblackCastleKing = g->blackCastleKing;
+  undo.OldblackCastleQueen = g->blackCastleQueen;
+
+  // play move
+  Piece piece = g->pieces[PositionToIndex(move.From)];
+  Piece piece2 = g->pieces[PositionToIndex(move.To)];
+
+  if (piece2.type != NONEPIECE) {
+    if (piece2.color == g->turn) {
+      assert(false && "capturing friendly piece error");
+    }
+  }
+
+  // clock
+  g->MoveClock++;
+  if (piece.type == PAWN || piece2.type != NONEPIECE) {
+    g->halfMoveClock = 0;
+  } else {
+    g->halfMoveClock++;
+  }
+
+  // Playing enpasstant
+  if (piece.type == PAWN && g->canEnpassant && move.To == g->enPassant) {
+    Position capturedPawn = move.To;
+    capturedPawn.rank += piece.color ? 1 : -1;
+    g->pieces[PositionToIndex(capturedPawn)] = {false, NONEPIECE};
+
+    undo.wasEnPassantCapture = true;
+    undo.enPassantCapturedSquare = capturedPawn;
+    undo.enPassantCapturedPiece = g->pieces[PositionToIndex(capturedPawn)];
+  }
+
+  g->canEnpassant = false;
+
+  // Adding enpassant
+  if (piece.type == PAWN) {
+    Position to = move.To;
+    to.rank -= (piece.color ? -2 : 2);
+    if (to == move.From) {
+      g->canEnpassant = true;
+      Position target = move.From;
+      target.rank += piece.color ? -1 : 1;
+      g->enPassant = target;
+    };
+  }
+
+  // Promotions
+  if (piece.type == PAWN && move.To.rank == (piece.color ? 0 : 7)) {
+    // TODO parse the promote type from uci isntead of ignoreting it
+    piece.type = move.promotion == NONEPIECE ? QUEEN : move.promotion;
+  }
+
+  // caslte
+  if (piece.type == KING && move.From.rank == (piece.color ? 0 : 7) &&
+      (move.From.file + 2 == move.To.file ||
+       move.From.file - 2 == move.To.file)) {
+
+    undo.wasCastle = true;
+    undo.CastledSide = (move.To.file > move.From.file);
+    if (move.From.file + 2 == move.To.file) {
+      Position rook_pos = move.To;
+      rook_pos.file += 1;
+      Piece rook = g->pieces[PositionToIndex(rook_pos)];
+      g->pieces[PositionToIndex(rook_pos)] = {false, NONEPIECE};
+      rook_pos = move.From;
+      rook_pos.file -= 1;
+      g->pieces[PositionToIndex(rook_pos)] = rook;
+    }
+    if (move.From.file - 2 == move.To.file) {
+      Position rook_pos = move.To;
+      rook_pos.file -= 1;
+      Piece rook = g->pieces[PositionToIndex(rook_pos)];
+      g->pieces[PositionToIndex(rook_pos)] = {false, NONEPIECE};
+      rook_pos = move.From;
+      rook_pos.file += 1;
+      g->pieces[PositionToIndex(rook_pos)] = rook;
+    }
+  };
+
+  // removing caslte rights
+  if (piece.type == KING) {
+    if (piece.color) {
+      g->whiteCastleKing = false;
+      g->whiteCastleQueen = false;
+    } else {
+      g->blackCastleKing = false;
+      g->blackCastleQueen = false;
+    }
+  }
+
+  // this part was written by ai
+  if (piece.type == ROOK) {
+    if (piece.color) {                                // White
+      if (move.From.rank == 7 && move.From.file == 0) // a1
+        g->whiteCastleQueen = false;
+
+      if (move.From.rank == 7 && move.From.file == 7) // h1
+        g->whiteCastleKing = false;
+    } else {                                          // Black
+      if (move.From.rank == 0 && move.From.file == 0) // a8
+        g->blackCastleQueen = false;
+
+      if (move.From.rank == 0 && move.From.file == 7) // h8
+        g->blackCastleKing = false;
+    }
+  }
+
+  // this part is also written with ai
+  if (piece2.type == ROOK) {
+    if (piece2.color) {                           // White rook captured
+      if (move.To.rank == 7 && move.To.file == 0) // a1
+        g->whiteCastleQueen = false;
+
+      if (move.To.rank == 7 && move.To.file == 7) // h1
+        g->whiteCastleKing = false;
+    } else {                                      // Black rook captured
+      if (move.To.rank == 0 && move.To.file == 0) // a8
+        g->blackCastleQueen = false;
+
+      if (move.To.rank == 0 && move.To.file == 7) // h8
+        g->blackCastleKing = false;
+    }
+  }
+
+  // playing the moves
+  g->pieces[PositionToIndex(move.To)] = piece;
+  g->pieces[PositionToIndex(move.From)] = {false, NONEPIECE};
+
+  // changing who turn it is
+  g->turn = !g->turn;
+
+  // 3 fold check
+  uint64_t key = GenerateZobristKey(g);
+
+  undo.zobristKey = key;
+
+  g->ThreeFoldMap[key]++;
+
+  if (g->ThreeFoldMap[key] >= 3) {
+    g->state = DRAW;
+  }
+
+  if (g->halfMoveClock >= 50) {
+    g->state = DRAW;
+  }
+
+  return undo;
+};
+void UnMakeMove(UndoMove undo, Game *g) {
+  g->pieces[PositionToIndex(undo.from)] = undo.movedPiece;
+
+  g->pieces[PositionToIndex(undo.to)] = undo.capturedPiece;
+
+  if (undo.wasEnPassantCapture) {
+    g->pieces[PositionToIndex(undo.enPassantCapturedSquare)] =
+        undo.enPassantCapturedPiece;
+  }
+
+  g->turn = undo.oldTurn;
+
+  g->canEnpassant = undo.oldCanEnpassant;
+  g->enPassant = undo.oldEnPassant;
+
+  g->halfMoveClock = undo.oldHalfMoveClock;
+  g->MoveClock = undo.oldMoveClock;
+
+  g->state = undo.oldState;
+
+  g->whiteCastleKing = undo.OldwhiteCastleKing;
+  g->whiteCastleQueen = undo.OldwhiteCastleQueen;
+  g->blackCastleKing = undo.OldblackCastleKing;
+  g->blackCastleQueen = undo.OldblackCastleQueen;
+
+  if (undo.wasCastle) {
+    if (undo.CastledSide) {
+      // rook f-file -> h-file
+      Position rookFrom = undo.to;
+      rookFrom.file -= 1; // f1/f8
+
+      Position rookTo = undo.to;
+      rookTo.file += 1; // h1/h8
+
+      g->pieces[PositionToIndex(rookTo)] = g->pieces[PositionToIndex(rookFrom)];
+      g->pieces[PositionToIndex(rookFrom)] = {false, NONEPIECE};
+    } else {
+      // rook d-file -> a-file
+      Position rookFrom = undo.to;
+      rookFrom.file += 1; // d1/d8
+
+      Position rookTo = undo.to;
+      rookTo.file -= 2; // a1/a8
+
+      g->pieces[PositionToIndex(rookTo)] = g->pieces[PositionToIndex(rookFrom)];
+      g->pieces[PositionToIndex(rookFrom)] = {false, NONEPIECE};
+    }
+  }
+  g->ThreeFoldMap[undo.zobristKey] -= 1;
+  if (g->ThreeFoldMap[undo.zobristKey] <= 0) {
+    g->ThreeFoldMap.erase(undo.zobristKey);
+  };
+};