From d0bbc4a14ad8f143bd2525cd71a67e1b8f27abfe Mon Sep 17 00:00:00 2001
From: Tibor Bizjak <tibor.bizjak@gmail.com>
Date: Tue, 10 Sep 2019 21:36:49 +0200
Subject: [PATCH] Added history managment

---
 chess.py | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 50 insertions(+), 3 deletions(-)

diff --git a/chess.py b/chess.py
index d17b385..bd42a7f 100644
--- a/chess.py
+++ b/chess.py
@@ -119,15 +119,18 @@ class Piece:
 
 class Game:
     def __init__(self):
+        self.index = 0
         self.make_board()
         self.moves = []
-        self.stack = []
+        self.AN_moves = []
+        self.history = []
         self.turn  = "white"
         self.can_castle = {"white" : {"queen" : True,
                                       "king"  : True},
                            "black" : {"queen" : True,
                                       "king"  : True}
                           }
+        self.history.append(deepcopy(self))
 
     def __repr__(self):
         # Unicode board representation
@@ -163,6 +166,31 @@ class Game:
         self.board["h1"].side = "king"
         self.board["h8"].side = "king"
 
+    def rebase(self):
+        self.moves = self.moves[:self.index+1]
+        self.history = self.history[:self.index+1]
+
+    def timetravel(self, i):
+        if i >= len(self.history) or i < 0:
+            return False
+        new = self.history[i]
+        self.board = new.board
+        self.turn = new.turn
+        self.can_castle = new.can_castle
+        self.index = i
+
+    def prev(self):
+        return self.timetravel(self.index-1)
+
+    def next(self):
+        return self.timetravel(self.index+1)
+
+    def last(self):
+        return self.timetravel(len(self.history)-1)
+
+    def first(self):
+        return self.timetravel(0)
+
     def is_empty(self, sq):
         return self.board[sq] == None
 
@@ -216,6 +244,7 @@ class Game:
         if not (are_empty and not_attacked):
             return False
 
+        self.rebase()
         self.board[king_move[1]] = self.board[king_move[0]]
         self.board[rook_move[1]] = self.board[rook_move[0]]
         self.board[king_move[0]] = Piece()
@@ -224,6 +253,8 @@ class Game:
         self.can_castle[color]["king"]  = False
         self.moves.append(king_move)
         self.turn = invert(self.turn)
+        self.history.append(deepcopy(self))
+        self.index += 1
         return True
 
     def move(self, source, target, promotion=None):
@@ -261,10 +292,13 @@ class Game:
         if new.is_check(self.turn):
             return False
 
+        self.rebase()
         self.moves.append((source, target))
         self.board = new.board
         self.can_castle = new.can_castle
         self.turn = invert(moved.color)
+        self.history.append(deepcopy(self))
+        self.index += 1
         return True
 
     def is_legal(self, source, target, promotion):
@@ -329,7 +363,8 @@ class Game:
                     r.append(jump)
             for t in targets:
                 a, b = move(t, dir), move(t, back)
-                en_passant = can_eat(b) and self.moves[-1] == (a,b)
+                en_passant = can_eat(b) and self.index>0 and\
+                             self.moves[self.index-1] == (a,b)
                 if can_eat(t) or en_passant:
                     r.append(t)
             return r
@@ -389,6 +424,7 @@ class Game:
         return valid, new
 
     def AN_move(self, move):
+        AN = move
         info = parse_AN(move)
         if info == False:
             return False
@@ -415,17 +451,28 @@ class Game:
             return False
         move = moves[0]
         self.move(*move)
+        self.AN_moves.append(AN)
         return True
 
 
 
 def test():
     game = Game()
-    while not game.is_stall():
+    move = ""
+    while not game.is_stall() and move!='q':
         move = input(">> ")
+        if move == "prev":
+            game.prev()
+            print(game)
+            continue
+        elif move == "next":
+            game.next()
+            print(game)
+            continue
         v = game.AN_move(move)
         if not v:
             print("Invalid")
             continue
         print(game)
+    print (game.history)