from axelrod.action import Action

from axelrod.player import Player

C, D = Action.C, Action.D

class Doubler(Player):
    """
    Cooperates except when the opponent has defected and
    the opponent's cooperation count is less than twice their defection count.

    Names:

    - Doubler: [Prison1998]_
    """

    name = "Doubler"
    classifier = {
        "stochastic": False,
        "memory_depth": float("inf"),
        "long_run_time": False,
        "inspects_source": False,
        "manipulates_source": False,
        "manipulates_state": False,
    }

    def strategy(self, opponent: Player) -> Action:
        """Actual strategy definition that determines player's action."""
        if not self.history:
            return C
        if (
            opponent.history[-1] == D
            and opponent.cooperations <= opponent.defections * 2
        ):
            return D
        return C