Files

135 lines
4.4 KiB
Python

"""Gymnasium environment that wraps the GameCli C# binary as a subprocess.
Speaks the line-delimited JSON protocol defined in:
docs/superpowers/specs/2026-07-17-cursor-following-lander-design.md
Each episode picks a random target in [0,1]^2 at reset time and holds it fixed.
Never terminates — episodes end via truncation at max_episode_steps.
"""
from __future__ import annotations
import json
import subprocess
from pathlib import Path
from typing import Any, Optional
import gymnasium as gym
import numpy as np
from gymnasium import spaces
class LanderCliEnv(gym.Env):
"""One CLI subprocess per env instance. Not thread-safe; safe under SubprocVecEnv."""
metadata = {"render_modes": []}
def __init__(
self,
cli_binary: str,
max_episode_steps: int = 1000,
) -> None:
super().__init__()
self._cli_binary = cli_binary
self._max_episode_steps = max_episode_steps
self._proc: Optional[subprocess.Popen] = None
self._target: tuple[float, float] = (0.5, 0.5)
self._step_count: int = 0
self._start_process()
self._read_init()
self.observation_space = spaces.Box(
low=-np.inf, high=np.inf, shape=(7,), dtype=np.float32
)
self.action_space = spaces.Discrete(4)
# -------- subprocess lifecycle --------
def _start_process(self) -> None:
self._proc = subprocess.Popen(
[self._cli_binary],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
text=True,
bufsize=1, # line-buffered
)
def _read_init(self) -> None:
assert self._proc is not None and self._proc.stdout is not None
line = self._proc.stdout.readline()
if not line:
raise RuntimeError("CLI died before emitting init handshake")
msg = json.loads(line)
if "init" not in msg:
raise RuntimeError(f"expected init handshake, got: {line!r}")
def _send(self, obj: dict[str, Any]) -> None:
assert self._proc is not None and self._proc.stdin is not None
self._proc.stdin.write(json.dumps(obj) + "\n")
self._proc.stdin.flush()
def _recv(self) -> dict[str, Any]:
assert self._proc is not None and self._proc.stdout is not None
line = self._proc.stdout.readline()
if not line:
raise RuntimeError("CLI closed stdout unexpectedly")
return json.loads(line)
# -------- gym.Env API --------
def reset(
self, *, seed: Optional[int] = None, options: Optional[dict] = None
) -> tuple[np.ndarray, dict]:
super().reset(seed=seed)
# Sample a fresh target each episode; the Gymnasium-provided
# np_random is deterministic given `seed`.
tx = float(self.np_random.uniform(0.05, 0.95))
ty = float(self.np_random.uniform(0.05, 0.95))
self._target = (tx, ty)
self._step_count = 0
cmd: dict[str, Any] = {"cmd": "reset"}
if seed is not None:
cmd["seed"] = int(seed)
self._send(cmd)
msg = self._recv()
obs = np.asarray(msg["obs"], dtype=np.float32)
# Overwrite the CLI's dummy (0.5, 0.5) target displacement with the real one.
# dx = target.X - ship.X, dy = target.Y - ship.Y.
obs[0] = tx - msg["state"]["x"]
obs[1] = ty - msg["state"]["y"]
return obs, {}
def step(self, action: int) -> tuple[np.ndarray, float, bool, bool, dict]:
self._send({"action": int(action), "target": list(self._target)})
msg = self._recv()
obs = np.asarray(msg["obs"], dtype=np.float32)
reward = float(msg["reward"])
self._step_count += 1
truncated = self._step_count >= self._max_episode_steps
terminated = False # continuous hover task
return obs, reward, terminated, truncated, {}
def close(self) -> None:
if self._proc is None:
return
try:
if self._proc.stdin is not None:
self._proc.stdin.close()
except (BrokenPipeError, OSError):
pass
try:
self._proc.wait(timeout=3)
except subprocess.TimeoutExpired:
self._proc.kill()
self._proc.wait(timeout=1)
self._proc = None
def __del__(self) -> None:
try:
self.close()
except Exception:
pass