from __future__ import annotations

import re
from abc import ABC, abstractmethod
from collections import deque
from dataclasses import dataclass, field
from typing import Deque, Optional, Pattern, Set


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):
    """Minimal agent that always returns the same command."""

    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):
    """Agent that inspects every noun it discovers in the room description."""

    look_command: str = "schau"
    inspect_command: str = "untersuche"
    nouns_pattern: Pattern[str] = field(
        default_factory=lambda: re.compile(r"\b[A-ZÄÖÜ][A-Za-zÄÖÜäöüß-]*\b")
    )
    last_output: str = field(default="", init=False)
    look_sent: bool = field(default=False, init=False)
    pending_targets: Deque[str] = field(default_factory=deque, init=False)
    seen_targets: Set[str] = field(default_factory=set, init=False)
    inspected_targets: Set[str] = field(default_factory=set, init=False)

    def observe(self, output: str) -> None:
        if not output:
            return
        self.last_output = output
        if not self.look_sent:
            return

        for noun in self.nouns_pattern.findall(output):
            target = noun.strip()
            key = target.lower()
            if not target or key in self.seen_targets:
                continue
            self.seen_targets.add(key)
            self.pending_targets.append(target)

    def decide(self) -> Optional[str]:
        if not self.look_sent:
            self.look_sent = True
            print("[Agent] Exploring room, sending 'schau'")
            return self.look_command

        if self.pending_targets:
            target = self.pending_targets.popleft()
            key = target.lower()
            self.inspected_targets.add(key)
            progress = f"[Agent] Explored {len(self.inspected_targets)}/{len(self.seen_targets)} — untersuche {target}"
            print(progress)
            return f"{self.inspect_command} {target}"

        return None