flutter: Add posKey and zobrist

And do some refactor.

src/ui/flutter_app/lib/mill/position.dart

@@ -24,8 +24,10 @@ import 'package:sanmill/services/audios.dart';
 
 import 'mills.dart';
 import 'types.dart';
+import 'zobrist.dart';
 
 int repetition = 0;
+late List<int> posKeyHistory;
 
 class StateInfo {
   // Copied when making a move
@@ -233,11 +235,11 @@ class Position {
         pieceToRemoveCount.toString() +
         " ";
 
-    int sideIsBlack = _sideToMove == PieceColor.black ? 1 : 0;
+    int sideIsWhite = _sideToMove == PieceColor.white ? 1 : 0;
 
     ss += st.rule50.toString() +
         " " +
-        (1 + (gamePly - sideIsBlack) ~/ 2).toString();
+        (1 + (gamePly - sideIsWhite) ~/ 2).toString();
 
     return ss;
   }
@@ -339,7 +341,42 @@ class Position {
     return true;
   }
 
-  // TODO: THREEFOLD_REPETITION
+  bool hasRepeated(List<Position> ss) {
+    for (int i = posKeyHistory.length - 2; i >= 0; i--) {
+      if (st.key == posKeyHistory[i]) {
+        return true;
+      }
+    }
+
+    int size = ss.length;
+
+    for (int i = size - 1; i >= 0; i--) {
+      if (ss[i].move.type == MoveType.remove) {
+        break;
+      }
+      if (st.key == ss[i].st.key) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  /// hasGameCycle() tests if the position has a move which draws by repetition.
+
+  bool hasGameCycle() {
+    for (var i in posKeyHistory) {
+      if (st.key == i) {
+        repetition++;
+        if (repetition == 3) {
+          repetition = 0;
+          return true;
+        }
+      }
+    }
+
+    return false;
+  }
 
 ///////////////////////////////////////////////////////////////////////////////
 
@@ -368,6 +405,10 @@ class Position {
         pieceInHandCount[PieceColor.white] = rule.piecesCount;
     pieceToRemoveCount = 0;
 
+    // TODO:
+    // MoveList<LEGAL>::create();
+    // create_mill_table();
+
     currentSquare = 0;
 
     record = "";
@@ -424,6 +465,8 @@ class Position {
 
       record = "(" + fileOf(s).toString() + "," + rankOf(s).toString() + ")";
 
+      updateKey(s);
+
       currentSquare = s;
 
       int n = millsCount(currentSquare);
@@ -459,6 +502,7 @@ class Position {
         Audios.playTone('place.mp3');
       } else {
         pieceToRemoveCount = rule.mayRemoveMultiple ? n : 1;
+        updateKeyMisc();
         action = Act.remove;
         Game.instance.focusIndex = squareToIndex[s] ?? invalidIndex;
         Audios.playTone('mill.mp3');
@@ -497,6 +541,9 @@ class Position {
       st.rule50++;
 
       board[s] = _grid[squareToIndex[s]!] = board[currentSquare];
+      updateKey(s);
+      revertKey(currentSquare);
+
       board[currentSquare] =
           _grid[squareToIndex[currentSquare]!] = Piece.noPiece;
 
@@ -516,6 +563,7 @@ class Position {
         }
       } else {
         pieceToRemoveCount = rule.mayRemoveMultiple ? n : 1;
+        updateKeyMisc();
         action = Act.remove;
         Game.instance.focusIndex = squareToIndex[s] ?? invalidIndex;
         Audios.playTone('mill.mp3');
@@ -543,11 +591,14 @@ class Position {
       return false;
     }
 
+    revertKey(s);
+
     Audios.playTone('remove.mp3');
 
     if (rule.hasBannedLocations && phase == Phase.placing) {
       // Remove and put ban
       board[s] = _grid[squareToIndex[s]!] = Piece.ban;
+      updateKey(s);
     } else {
       // Remove only
       board[s] = _grid[squareToIndex[s]!] = Piece.noPiece;
@@ -569,6 +620,7 @@ class Position {
     currentSquare = 0;
 
     pieceToRemoveCount--;
+    updateKeyMisc();
 
     if (pieceToRemoveCount > 0) {
       return true;
@@ -629,6 +681,10 @@ class Position {
     return true;
   }
 
+  String getWinner() {
+    return winner;
+  }
+
   void setGameOver(String w, GameOverReason reason) {
     phase = Phase.gameOver;
     gameOverReason = reason;
@@ -677,9 +733,7 @@ class Position {
       return true;
     }
 
-    bool isNoWay = isAllSurrounded();
+    if (phase == Phase.moving && action == Act.select && isAllSurrounded()) {
-    //print("phase = $phase, action = $action, isAllSurrounded = $isNoWay");
-    if (phase == Phase.moving && action == Act.select && isNoWay) {
       if (rule.isLoseButNotChangeSideWhenNoWay) {
         setGameOver(
             PieceColor.opponent(sideToMove()), GameOverReason.loseReasonNoWay);
@@ -704,6 +758,7 @@ class Position {
 
         if (board[s] == Piece.ban) {
           board[s] = _grid[squareToIndex[s]!] = Piece.noPiece;
+          revertKey(s);
         }
       }
     }
@@ -711,46 +766,38 @@ class Position {
 
   void setSideToMove(String color) {
     _sideToMove = color;
-    us = _sideToMove;
+    //us = color;
-    them = PieceColor.opponent(us);
+    them = PieceColor.opponent(_sideToMove);
   }
 
   void changeSideToMove() {
-    them = _sideToMove;
+    setSideToMove(PieceColor.opponent(_sideToMove));
-    _sideToMove = PieceColor.opponent(_sideToMove);
+    st.key ^= Zobrist.side;
     print("$_sideToMove to move.");
   }
 
-  int pieceOnBoardCountCount() {
+  int updateKey(int s) {
-    pieceOnBoardCount[PieceColor.black] =
+    String pieceType = colorOn(s);
-        pieceOnBoardCount[PieceColor.white] = 0;
 
-    for (int f = 1; f < fileExNumber; f++) {
+    st.key ^= Zobrist.psq[pieceColorIndex[pieceType]!][s];
-      for (int r = 0; r < rankNumber; r++) {
-        int s = f * rankNumber + r;
-        if (board[s] == Piece.blackStone) {
-          if (pieceOnBoardCount[PieceColor.black] != null) {
-            pieceOnBoardCount[PieceColor.black] =
-                pieceOnBoardCount[PieceColor.black]! + 1;
-          }
-        } else if (board[s] == Piece.whiteStone) {
-          if (pieceOnBoardCount[PieceColor.white] != null) {
-            pieceOnBoardCount[PieceColor.white] =
-                pieceOnBoardCount[PieceColor.white]! + 1;
-          }
-        }
-      }
-    }
 
-    if (pieceOnBoardCount[PieceColor.black]! > rule.piecesCount ||
+    return st.key;
-        pieceOnBoardCount[PieceColor.white]! > rule.piecesCount) {
-      return -1;
-    }
-
-    return pieceOnBoardCount[PieceColor.black]! +
-        pieceOnBoardCount[PieceColor.white]!;
   }
 
+  int revertKey(int s) {
+    return updateKey(s);
+  }
+
+  int updateKeyMisc() {
+    st.key = st.key << Zobrist.KEY_MISC_BIT >> Zobrist.KEY_MISC_BIT;
+
+    st.key |= (pieceToRemoveCount) << (32 - Zobrist.KEY_MISC_BIT);
+
+    return st.key;
+  }
+
+  ///////////////////////////////////////////////////////////////////////////////
+
   String colorOn(int sq) {
     return board[sq];
   }
@@ -837,8 +884,6 @@ class Position {
     return true;
   }
 
-  // TODO: surrounded_pieces_count
-
   bool isAllSurrounded() {
     // Full
     if (pieceOnBoardCount[PieceColor.black]! +
@@ -879,6 +924,8 @@ class Position {
     return (s == 16 || s == 18 || s == 20 || s == 22);
   }
 
+  ///////////////////////////////////////////////////////////////////////////////
+
   int getNPiecesInHand() {
     pieceInHandCount[PieceColor.black] =
         rule.piecesCount - pieceOnBoardCount[PieceColor.black]!;
@@ -931,8 +978,34 @@ class Position {
     return -1;
   }
 
-  String getWinner() {
+  int pieceOnBoardCountCount() {
-    return winner;
+    pieceOnBoardCount[PieceColor.black] =
+        pieceOnBoardCount[PieceColor.white] = 0;
+
+    for (int f = 1; f < fileExNumber; f++) {
+      for (int r = 0; r < rankNumber; r++) {
+        int s = f * rankNumber + r;
+        if (board[s] == Piece.blackStone) {
+          if (pieceOnBoardCount[PieceColor.black] != null) {
+            pieceOnBoardCount[PieceColor.black] =
+                pieceOnBoardCount[PieceColor.black]! + 1;
+          }
+        } else if (board[s] == Piece.whiteStone) {
+          if (pieceOnBoardCount[PieceColor.white] != null) {
+            pieceOnBoardCount[PieceColor.white] =
+                pieceOnBoardCount[PieceColor.white]! + 1;
+          }
+        }
+      }
+    }
+
+    if (pieceOnBoardCount[PieceColor.black]! > rule.piecesCount ||
+        pieceOnBoardCount[PieceColor.white]! > rule.piecesCount) {
+      return -1;
+    }
+
+    return pieceOnBoardCount[PieceColor.black]! +
+        pieceOnBoardCount[PieceColor.white]!;
   }
 
 ///////////////////////////////////////////////////////////////////////////////

src/ui/flutter_app/lib/mill/types.dart

@@ -155,6 +155,13 @@ class PieceColor {
   String operator -(String c) => opponent(c);
 }
 
+Map<String, int> pieceColorIndex = {
+  PieceColor.none: 0,
+  PieceColor.black: 1,
+  PieceColor.white: 2,
+  PieceColor.ban: 3
+};
+
 enum Phase { none, ready, placing, moving, gameOver }
 
 enum Act { none, select, place, remove }
@@ -234,7 +241,7 @@ enum LineDirection { horizontal, vertical, slash }
 
 const lineDirectionNumber = 3;
 
-enum File { A, B, C }
+enum File { none, A, B, C }
 
 const fileNumber = 3;
 const fileExNumber = fileNumber + 2;

src/ui/flutter_app/lib/mill/zobrist.dart

@@ -0,0 +1,193 @@
+/*
+  This file is part of Sanmill.
+  Copyright (C) 2019-2021 The Sanmill developers (see AUTHORS file)
+
+  Sanmill is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Sanmill is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+class Zobrist {
+  static const int KEY_MISC_BIT = 2;
+  static var psq = [
+    [
+      0x4E421A,
+      0x3962FF,
+      0x6DB6EE,
+      0x219AE1,
+      0x1F3DE2,
+      0xD9AACB,
+      0xD51733,
+      0xD3F9EA,
+      0xF5A7BB,
+      0xDC4109,
+      0xEE4319,
+      0x7CDA7A,
+      0xFD7B4D,
+      0x4138BE,
+      0xCCBB2D,
+      0xDA6097,
+      0x06D827,
+      0xCBC16C,
+      0x46F125,
+      0xE29F22,
+      0xCAAB94,
+      0x5B02DB,
+      0x877CD6,
+      0x35E438,
+      0x49FDAE,
+      0xE68314,
+      0xBE1664,
+      0x1F49D3,
+      0x50F5B1,
+      0x149AAF,
+      0xF509B9,
+      0x47AEB5,
+      0x18E993,
+      0x76BB4F,
+      0xFE1739,
+      0xF87B87,
+      0x0A8CD2,
+      0x630C6B,
+      0x88F5B4,
+      0x0A583E,
+    ],
+    [
+      0xA0128E,
+      0x6F2251,
+      0x51E99D,
+      0x6D35BF,
+      0x66D6D9,
+      0x87D366,
+      0x75A57A,
+      0x534FC4,
+      0x1FE34B,
+      0xAD6FB0,
+      0xE5679D,
+      0xF88AFF,
+      0x0462DA,
+      0x4BDE96,
+      0xF28912,
+      0x10537E,
+      0x26D8EA,
+      0x37E6E7,
+      0x0871D9,
+      0xCD5F4F,
+      0xF4AFA1,
+      0x44A51B,
+      0x772656,
+      0x8B7965,
+      0xD8F17D,
+      0x80F3D7,
+      0x6B6206,
+      0x19B8BB,
+      0xFBC229,
+      0x0FCAB4,
+      0xFD7374,
+      0xA647B9,
+      0x296A8D,
+      0xA3D742,
+      0x624D6D,
+      0x459FD4,
+      0xCE8C26,
+      0x965448,
+      0x410171,
+      0x1EDD7A,
+    ],
+    [
+      0x1FCF95,
+      0xA5634E,
+      0x21976A,
+      0x32902D,
+      0x55A27C,
+      0x49EC5F,
+      0x0176A1,
+      0xCAAAEF,
+      0x145886,
+      0xB4C808,
+      0x0153EE,
+      0x7D78DF,
+      0xE9C3C5,
+      0x66B7A6,
+      0x3CD930,
+      0xDBBA23,
+      0xF19841,
+      0x6BEFDF,
+      0xB979FE,
+      0xBA4D06,
+      0x96AECF,
+      0x33B96E,
+      0x76A99C,
+      0x1B8762,
+      0x747B20,
+      0x0DEC24,
+      0xA4E632,
+      0xBA2442,
+      0x59C91B,
+      0x41482D,
+      0xF2CD39,
+      0x30E9C1,
+      0x6B156D,
+      0xC7F191,
+      0x012D36,
+      0xC66B36,
+      0x631560,
+      0xA891FC,
+      0xF6C8AC,
+      0xD80B94,
+    ],
+    [
+      0xF641E9,
+      0xF164BF,
+      0x2DBE4C,
+      0xE2A40C,
+      0x53FA06,
+      0x4F3117,
+      0x0ACA70,
+      0x2C72F5,
+      0xC81047,
+      0x4B76AE,
+      0xEB55C8,
+      0x0DB6EF,
+      0x7F57AB,
+      0x22D060,
+      0x390554,
+      0xDE9A43,
+      0x6583AF,
+      0x41D141,
+      0x9CBF92,
+      0x7E528F,
+      0x2BEFA1,
+      0x5C5FDC,
+      0x4DDAFA,
+      0x7C98A1,
+      0x65A13B,
+      0x2953BF,
+      0x8769A8,
+      0xE6DCA1,
+      0xD01A6E,
+      0xBCD935,
+      0x175659,
+      0xAD5A73,
+      0xB04E7D,
+      0x815F53,
+      0x12469A,
+      0xB2F25C,
+      0x564E4B,
+      0xD19437,
+      0xA4F63C,
+      0x7169E5,
+    ]
+  ];
+
+  static int side = 0x201906;
+}