Implement Iterative Deepening Minmax

src/classes/Engines.py

@@ -1,4 +1,4 @@
-import random, math, time
+import random, math, time, signal
 
 class PlayerEngine:
     def __init__(self, player, logger, heuristic, options: dict = {}):
@@ -7,6 +7,7 @@ class PlayerEngine:
         self.logger = logger
         self.heuristic = heuristic
         self.options = options
+        self.interrupt_search = False
         self.logger.info("Init engine {}, options:{}".format(
             self.__class__.__name__,
             self.options
@@ -92,7 +93,7 @@ class MinmaxPlayerEngine(PlayerEngine):
         nodes = 1
         leafs = 0
         move = ''
-        if depth == 0 or board.is_game_over():
+        if depth == 0 or board.is_game_over() or self.interrupt_search:
             leafs +=1
             return self.heuristic.get(board, self.player), nodes, leafs
         
@@ -192,3 +193,50 @@ class AlphabetaPlayerEngine(PlayerEngine):
                     return alpha, nodes, leafs
             return beta, nodes, leafs
 
+
+class MinmaxDeepeningPlayerEngine(MinmaxPlayerEngine):
+
+    def get_move(self, board):
+        super().get_move(board)
+        self.interrupt_search = False
+        
+        # Get an alarm signal to stop iterations
+        signal.signal(signal.SIGALRM, self.alarm_handler)
+        signal.alarm(self.options['time_limit'])
+        depth = 1
+        value = -math.inf
+        nodes = 1
+        leafs = 0
+        move = None
+
+        # We can go deeper than blank place in our board, then we must get
+        # numbers of avaible place
+        max_depth =  (board.get_board_size()**2) - (
+                board.get_nb_pieces()[0] + board.get_nb_pieces()[1])
+
+        # Iterate depth while our alarm does not trigger and there is enougth
+        # avaiable move to play
+        while not self.interrupt_search and depth <= max_depth:
+            for m in board.legal_moves():
+                board.push(m)
+                v, n, l = self.checkMinMax(board, False, depth - 1)
+                if v > value:
+                    value = v
+                    move = m
+                    self.logger.debug("found a better move: {} (heuristic:{})".format(
+                        move,
+                        value
+                        ))
+                nodes += n
+                leafs += l
+                board.pop()
+            depth = depth + 1
+            self.logger.debug("id_minmax - depth reached: {} | max depth : {}".format(
+            depth - 1,
+            max_depth
+        ))
+        return move
+
+    def alarm_handler(self, signal, frame):
+        self.logger.debug("Raise SIGALMR Signal")
+        self.interrupt_search = True