From a0033627ccf8770c1a7d067a3b881425dfe5331e Mon Sep 17 00:00:00 2001
From: Jerome Bedier <jerome.bedier@ecam.fr>
Date: Thu, 22 May 2025 22:47:44 +0200
Subject: [PATCH] to avoid dumb autoplayer best move + random

---
 src/backend/AutoPlayer.java | 82 ++++++++++++++++++++++++++++++-------
 1 file changed, 67 insertions(+), 15 deletions(-)

diff --git a/src/backend/AutoPlayer.java b/src/backend/AutoPlayer.java
index 6b6fd6b..98da544 100644
--- a/src/backend/AutoPlayer.java
+++ b/src/backend/AutoPlayer.java
@@ -1,32 +1,84 @@
 package backend;
 
 import java.util.ArrayList;
+import java.util.List;
 import java.util.Random;
 
 public class AutoPlayer {
+    private Integer lastMovedPieceHash = null; // Use piece's position and color for tracking
 
-    /**
-     * Returns a random legal move for the active player.
-     */
     public Move computeBestMove(Board board) {
-        ArrayList<Piece> pieces = board.getPieces();
-        ArrayList<Move> allMoves = new ArrayList<>();
-        boolean isWhite = board.isTurnWhite();
+        // Stop if only one king is left
+        int kingCount = 0;
+        for (Piece piece : board.getPieces()) {
+            if (piece.getType() == PieceType.King) kingCount++;
+        }
+        if (kingCount <= 1) {
+            return null;
+        }
+
+        ArrayList<Piece> pieces = board.getPieces();
+        boolean isWhite = board.isTurnWhite();
+        int bestPriority = Integer.MIN_VALUE;
+        List<Move> bestMoves = new ArrayList<>();
+        List<Integer> movePieceHashes = new ArrayList<>();
 
-        // Collect all legal moves for all of the active player's pieces
         for (Piece piece : pieces) {
             if (piece.isWhite() == isWhite) {
+                // Skip if this piece was just moved last time
+                int pieceHash = (piece.getX()*31 + piece.getY()) * (piece.isWhite() ? 1 : -1);
+                if (lastMovedPieceHash != null && pieceHash == lastMovedPieceHash) {
+                    continue;
+                }
+
                 ArrayList<Move> moves = board.getLegalMoves(piece);
-                allMoves.addAll(moves);
+                for (Move move : moves) {
+                    Board copy = new Board(board);
+                    copy.playMove(move);
+                    Piece enemyKing = copy.findKing(!isWhite);
+                    if (enemyKing == null) {
+                        // Move that captures the king (not standard chess, but per your requirements)
+                        // Remember which piece makes this move
+                        bestMoves.clear();
+                        bestMoves.add(move);
+                        movePieceHashes.clear();
+                        movePieceHashes.add(pieceHash);
+                        bestPriority = Integer.MAX_VALUE;
+                        break;
+                    }
+                    // Manhattan distance from this piece (after move) to enemy king
+                    int dist = Math.abs(move.getToX() - enemyKing.getX()) + Math.abs(move.getToY() - enemyKing.getY());
+                    int priority = -dist;
+
+                    // Bonus if move puts king in check
+                    if (copy.isKingInCheck(!isWhite)) {
+                        priority += 1000;
+                    }
+
+                    if (priority > bestPriority) {
+                        bestPriority = priority;
+                        bestMoves.clear();
+                        bestMoves.add(move);
+                        movePieceHashes.clear();
+                        movePieceHashes.add(pieceHash);
+                    } else if (priority == bestPriority) {
+                        bestMoves.add(move);
+                        movePieceHashes.add(pieceHash);
+                    }
+                }
             }
         }
-
-        if (allMoves.isEmpty()) {
-            return null; // No moves = checkmate or stalemate
-        }
-
-        // Pick a random move
+        if (bestMoves.isEmpty()) return null;
+        // Randomly pick among best moves
         Random rand = new Random();
-        return allMoves.get(rand.nextInt(allMoves.size()));
+        int idx = rand.nextInt(bestMoves.size());
+        // Set last moved piece hash for next time
+        lastMovedPieceHash = movePieceHashes.get(idx);
+        return bestMoves.get(idx);
+    }
+
+    // Optional: Call this after a human move to reset tracking
+    public void resetLastMovedPiece() {
+        lastMovedPieceHash = null;
     }
 }
\ No newline at end of file