client.py

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree.

"""
Chess Environment HTTP Client.

This module provides the client for connecting to a Chess Environment server
over HTTP.
"""

from typing import Any, Dict, Optional

from openenv_core.client_types import StepResult
from openenv_core.env_server.types import State
from openenv_core.http_env_client import HTTPEnvClient

from .models import ChessAction, ChessObservation


class ChessEnv(HTTPEnvClient[ChessAction, ChessObservation]):
    """
    HTTP client for the Chess Environment.

    This client connects to a ChessEnvironment HTTP server and provides
    methods to interact with it: reset(), step(), and state access.

    Example:
        >>> client = ChessEnv(base_url="http://localhost:8000")
        >>> result = client.reset()
        >>> print(result.observation.board_fen)
        >>>
        >>> result = client.step(ChessAction(move="e2e4"))
        >>> print(result.observation.game_status)
        >>> print(result.reward)
    """

    def _step_payload(self, action: ChessAction) -> Dict:
        return {
            "move": action.move,
        }

    def _parse_result(self, payload: Dict) -> StepResult[ChessObservation]:
        obs_data = payload.get("observation", {})
        observation = ChessObservation(
            board_fen=obs_data.get("board_fen", ""),
            legal_moves=obs_data.get("legal_moves", []),
            white_move=obs_data.get("white_move", ""),
            black_move=obs_data.get("black_move"),
            material_balance=obs_data.get("material_balance", 0.0),
            game_status=obs_data.get("game_status", "ongoing"),
            captured_pieces=obs_data.get("captured_pieces", []),
            done=payload.get("done", False),
            reward=payload.get("reward"),
            metadata=obs_data.get("metadata", {}),
        )

        return StepResult(
            observation=observation,
            reward=payload.get("reward"),
            done=payload.get("done", False),
        )

    def _parse_state(self, payload: Dict) -> State:
        return State(
            episode_id=payload.get("episode_id"),
            step_count=payload.get("step_count", 0),
        )