Worked a bit

shenzhen_solitaire/solver.py

@@ -1,11 +1,77 @@
 """Contains solver for solitaire"""
-from typing import List, Tuple
+from typing import List, Tuple, Iterator, Set, Optional
 from .board import Board
 from . import board_actions
+from .board_possibilities import possible_actions
+
+
+class ActionStack:
+    iterator_stack: List[Iterator[board_actions.Action]]
+    action_stack: List[Optional[board_actions.Action]]
+    index_stack: List[int]
+
+    def __init__(self) -> None:
+        self.iterator_stack = []
+        self.index_stack = []
+        self.action_stack = []
+
+    def push(self, board: Board) -> None:
+        self.iterator_stack.append(possible_actions(board))
+        self.action_stack.append(None)
+        self.index_stack.append(0)
+
+    def get(self) -> Optional[board_actions.Action]:
+        try:
+            self.action_stack[-1] = next(self.iterator_stack[-1])
+        except StopIteration:
+            return None
+        self.index_stack[-1] += 1
+        return self.action_stack[-1]
+
+    def pop(self) -> None:
+        self.action_stack.pop()
+        self.iterator_stack.pop()
+        self.index_stack.pop()
+
+    def __len__(self) -> int:
+        return len(self.index_stack)
 
 
 class SolitaireSolver:
     """Solver for Shenzhen Solitaire"""
 
     search_board: Board
-    stack: List[Tuple[board_actions.Action, int]]
+    stack: ActionStack
+    state_set: Set[int]
+
+    def __init__(self, board: Board) -> None:
+        self.search_board = board
+        self.state_set = {board.state_identifier}
+        self.stack = ActionStack()
+        self.stack.push(self.search_board)
+
+    def solve(self) -> List[board_actions.Action]:
+        applied = True
+        action = None
+        while self.stack:
+            last_action = action
+            action = self.stack.get()
+            if not action:
+                if last_action and applied:
+                    last_action.undo(self.search_board)
+                    assert (self.search_board.state_identifier
+                            in self.state_set)
+                self.stack.pop()
+                continue
+            action.apply(self.search_board)
+            print(f"Applying {str(action)}")
+            applied = True
+            if self.search_board.state_identifier in self.state_set:
+                action.undo(self.search_board)
+                applied = False
+                assert self.search_board.state_identifier in self.state_set
+                continue
+            self.state_set.add(self.search_board.state_identifier)
+            self.stack.push(self.search_board)
+
+        return self.stack.action_stack