"""Public client entry points."""

from typing import List, Optional

import requests

from .poll import ServerAgent


class PyClient:
    """Host games between discovered server agents."""

    def __init__(self, hosts: List[str], debug : bool = False) -> None:
        """
        Create a PyClient.

        :param hosts: URLs of servers that can participate.
        :type hosts: List[str]
        :raises ValueError: If no reachable servers are provided.
        """
        self.agents: List[ServerAgent] = []
        self.debug = debug
        self.hosts: List[str] = []

        for host in hosts:
            agent = self.__discover_host(host)
            if agent is not None:
                self.agents.append(agent)
                self.hosts.append(agent.url)

        if len(self.hosts) <= 0:
            raise ValueError(
                "No valid hosts found! Check your internet connection or verify the URLs are correct."
            )

    def __discover_host(self, url: str) -> Optional[ServerAgent]:
        try:
            return ServerAgent.from_url(url, debug=self.debug)
        except (requests.exceptions.RequestException, ValueError):
            return None

    def play_game(self, name : str, game, timeout : float = 1.0):
        """
            Play a given game. Ask the registered agents to participate.
        """
        agents = [ agent for agent in self.agents if name in agent.games ]
        states = []

        current_state = game.empty()

        while current_state.winner() is None:
            player : int = current_state.player_to_move()

            if len(agents) < player:
                raise KeyError(
                    f"{player} players for game {name}, found only {len(agents)}"
                )
            
            # Ask for move
            agent = agents[player-1]
            payload = agent.poll(
                game=current_state.action_name(),
                payload=current_state.as_seen_by(player),
                timeout=timeout,
            )

            # Calculate move
            current_state = current_state.move(payload)

            # Save the results
            states.append((player, payload, current_state))
        
        return states

    def verify_host(self, url: str) -> bool:
        """
        Verify whether the URL seems to contain a link to a playable server.
        """
        return self.__discover_host(url) is not None


__all__ = ["PyClient", "ServerAgent"]