class NimGame:
    """A Nim game class based off NimGameStub.
    """
    def get_initial_state(self):
        ''' Constructs the game board and has player 1 start the game. '''
        return {
            "board": [1, 3, 5, 7],
            "first_player": True
        }

    def get_next_state(self, state, action):
        ''' Creates a copy of the current board and then makes adjustments
        based on the chosen action from a player's turn. '''
        new_board = state["board"].copy()
        new_board[action[0]] = new_board[action[0]] - action[1]
        return {
            "board": new_board,
            "first_player": not state["first_player"],
        }
    
    def get_actions(self, state):
        ''' Construct the list of actions that can be taken by a player.
        Is there a more efficient way of doign this? '''
        actions = []
        new_board = state["board"].copy()
        for i in range(4):                      # check the four rows of the board
            if new_board[i] > 0:                # if a row is not empty
                for j in range(1,4):            # check if you can remove 1, 2, or 3 ticks in the row
                    if j <= new_board[i]:       # if so
                        actions.append((i,j))   # include that as an option
        return actions   

    def get_reward(self, state):
        ''' Reports who wins. '''
        if state["first_player"]:
            return 1    # If it is the player's turn and there is nothing on the board, then it was the robot who crossed off the last line.
        return 0        # Otherwise, the first player made the last move and lost.

    def is_over(self, state):
        ''' Reports true if there are no more lines to cross. '''
        if all(ticks == 0 for ticks in state["board"]):
            return True
        return False

    def get_objective(self, state):
        ''' Reports the desired obejctive to help choose the move that 
        yields the optimal reward under the lookahead_strategy for
        computer players. '''
        return max if state["first_player"] else min