from __future__ import annotations

from abc import ABC, abstractmethod
from dataclasses import dataclass, field
from typing import Optional


class Agent(ABC):
    """Interface for autonomous Telnet actors."""

    @abstractmethod
    def observe(self, output: str) -> None:
        """Receive the latest text emitted by the server."""

    @abstractmethod
    def decide(self) -> Optional[str]:
        """Return the next command to send, or ``None`` to stay idle."""


@dataclass
class SimpleAgent(Agent):
    """Very small stateful agent that decides which command to run next."""

    default_command: str = "schau"
    last_output: str = field(default="", init=False)

    def observe(self, output: str) -> None:
        if output:
            self.last_output = output

    def decide(self) -> Optional[str]:
        return self.default_command


@dataclass
class ExploreAgent(Agent):
    """Very small stateful agent that decides which command to run next."""

    default_command: str = "untersuche boden"
    last_output: str = field(default="", init=False)

    def observe(self, output: str) -> None:
        if output:
            self.last_output = output

    def decide(self) -> Optional[str]:
        return self.default_command