code/train/grid_puzzle_plugin.py

"""SPAgent GRPO plugin for deterministic Sokoban and FifteenPuzzle.

The plugin mirrors the FrozenLake v3 training contract:

- explicit per-turn ``<image>[image: ...]`` placement;
- canonical ``<think>`` plus ``<tool_call>``/``<answer>`` output;
- stateful one-step ``move`` tool execution;
- cumulative image history after valid moves;
- final-answer replay from the initial state;
- per-rollout trajectory logs with reward backfill.

Datasets are built by ``train/build_grid_puzzle_training_data.py``.
"""

from __future__ import annotations

import json
import os
import re
import sys
import uuid
from datetime import datetime
from pathlib import Path
from typing import Any, Dict, List, Mapping, Optional


REPO_ROOT = Path(__file__).resolve().parents[1]
if str(REPO_ROOT) not in sys.path:
    sys.path.insert(0, str(REPO_ROOT))

from spagent.grid_puzzle_protocol import (  # noqa: E402
    SUPPORTED_TASKS,
    clone_state,
    create_tool_response,
    decode_initial_state,
    encode_initial_state,
    parse_action_tokens,
    render_state,
    replay_actions,
    step_state,
)

from swift.llm import RolloutInferRequest  # noqa: E402

sys.path.insert(0, str(Path(__file__).resolve().parent))
import grpo_filtered_trainer  # noqa: E402,F401
from swift.llm.infer.protocol import ChatCompletionResponseChoice  # noqa: E402
from swift.plugin import ORM, orms  # noqa: E402
from swift.plugin.multi_turn import MultiTurnScheduler, multi_turns  # noqa: E402
from swift.utils import get_logger  # noqa: E402


logger = get_logger()

TOOL_CALL_RE = re.compile(r"<tool_call>\s*(.*?)\s*</tool_call>", re.DOTALL)
ANSWER_RE = re.compile(r"<answer>(.*?)</answer>", re.DOTALL)
_THINK_INNER = r"(?:(?!</think>|<tool_call>|<answer>).)*"
_TOOL_CALL_TURN_RE = re.compile(
    rf"^<think>{_THINK_INNER}</think>\s*<tool_call>.*?</tool_call>(?![\s\S])",
    re.DOTALL,
)
_ANSWER_TURN_RE = re.compile(
    rf"^<think>{_THINK_INNER}</think>\s*<answer>.*?</answer>(?![\s\S])",
    re.DOTALL,
)


def _is_canonical_format(completion: str) -> bool:
    value = (completion or "").strip()
    return (
        _TOOL_CALL_TURN_RE.match(value) is not None
        or _ANSWER_TURN_RE.match(value) is not None
    )


def _batch_values(value: Any, count: int) -> List[Any]:
    if isinstance(value, list) and len(value) == count:
        return value
    return [value] * count


class GridPuzzleReward(ORM):
    """Reward a final direction sequence that solves the recorded puzzle."""

    def __call__(
        self,
        completions,
        task_id=None,
        initial_state=None,
        **kwargs,
    ) -> List[float]:
        completions = list(completions or [])
        tasks = _batch_values(task_id, len(completions))
        states = _batch_values(initial_state, len(completions))
        rewards: List[float] = []
        for completion, task, state in zip(completions, tasks, states):
            match = ANSWER_RE.search(completion or "")
            if not match or task not in SUPPORTED_TASKS or not state:
                rewards.append(0.0)
                continue
            actions = parse_action_tokens(match.group(1))
            solved = bool(actions) and replay_actions(task, state, actions)
            rewards.append(1.0 if solved else 0.0)
        return rewards


orms["grid_puzzle_reward"] = GridPuzzleReward


class GridPuzzleFormatReward(ORM):
    """Match the FrozenLake v3 canonical format reward scale."""

    def __call__(self, completions, **kwargs) -> List[float]:
        rewards: List[float] = []
        for completion in completions or []:
            completion = completion or ""
            canonical = _is_canonical_format(completion)
            match = ANSWER_RE.search(completion)
            valid_actions = bool(
                match and parse_action_tokens(match.group(1))
            )
            rewards.append(
                0.3 * float(canonical) + 0.2 * float(valid_actions)
            )
        return rewards


orms["grid_puzzle_format"] = GridPuzzleFormatReward


class GridPuzzleScheduler(MultiTurnScheduler):
    """Stateful scheduler shared by Sokoban and FifteenPuzzle."""

    def __init__(self, max_turns: int = 100, *args, **kwargs):
        super().__init__(max_turns=max_turns, *args, **kwargs)
        self.tool_img_dir = Path(
            os.environ.get("GRID_PUZZLE_IMG_DIR", "/tmp/grid_puzzle_rollout")
        )
        self.tool_img_dir.mkdir(parents=True, exist_ok=True)

        base_traj_dir = os.environ.get("TRAJ_LOG_DIR", "")
        if base_traj_dir:
            run_id = (
                os.environ.get("RUN_ID")
                or datetime.now().strftime("%Y%m%d-%H%M%S")
            )
            self._traj_log_dir = os.path.join(base_traj_dir, run_id)
            os.makedirs(self._traj_log_dir, exist_ok=True)
            logger.info(
                f"Grid-puzzle trajectory logging enabled: {self._traj_log_dir}"
            )
        else:
            self._traj_log_dir = ""
        self._traj_step_counter = 0
        self._traj_rank = os.environ.get(
            "RANK", os.environ.get("LOCAL_RANK", "0")
        )
        self._trajectories: Dict[str, Dict[str, Any]] = {}

    def _state(self, infer_request: RolloutInferRequest) -> Dict[str, Any]:
        if (
            not hasattr(infer_request, "data_dict")
            or infer_request.data_dict is None
        ):
            infer_request.data_dict = {}
        data = infer_request.data_dict
        if "_grid_puzzle" not in data:
            task_id = data.get("task_id")
            initial_state = data.get("initial_state")
            if task_id not in SUPPORTED_TASKS:
                raise RuntimeError(
                    f"GridPuzzleScheduler requires task_id in {SUPPORTED_TASKS}; "
                    f"got {task_id!r}"
                )
            if not initial_state:
                raise RuntimeError(
                    "GridPuzzleScheduler requires the dataset column "
                    "`initial_state`."
                )
            decoded = decode_initial_state(initial_state)
            encoded = encode_initial_state(decoded)
            data["initial_state"] = encoded
            data["_grid_puzzle"] = {
                "task_id": task_id,
                "initial_state": encoded,
                "state": clone_state(decoded),
                "done": False,
                "success": False,
                "actions": [],
            }
        if "rollout_uuid" not in data:
            data["rollout_uuid"] = uuid.uuid4().hex[:12]
        if "session_messages" not in data:
            data["session_messages"] = [
                {"role": message["role"], "content": message["content"]}
                for message in (infer_request.messages or [])
                if message.get("role") != "assistant"
            ]
        return data["_grid_puzzle"]

    def _get_sample_id(self, infer_request: RolloutInferRequest) -> str:
        if (
            not hasattr(infer_request, "data_dict")
            or infer_request.data_dict is None
        ):
            infer_request.data_dict = {}
        data = infer_request.data_dict
        if "rollout_uuid" not in data:
            data["rollout_uuid"] = uuid.uuid4().hex[:12]
        return data["rollout_uuid"]

    def _compute_rewards(
        self,
        final_response: str,
        task_id: Optional[str],
        initial_state: Optional[str | Mapping[str, Any]],
    ) -> Dict[str, Any]:
        output: Dict[str, Any] = {
            "format_reward": 0.0,
            "outcome_reward": 0.0,
            "total_reward": 0.0,
            "acc_reward": 0.0,
            "extracted_answer": None,
        }
        canonical = _is_canonical_format(final_response or "")
        match = ANSWER_RE.search(final_response or "")
        actions: List[str] = []
        if match:
            output["extracted_answer"] = match.group(1).strip()
            actions = parse_action_tokens(match.group(1))
        output["format_reward"] = (
            0.3 * float(canonical) + 0.2 * float(bool(actions))
        )
        if (
            task_id in SUPPORTED_TASKS
            and initial_state
            and actions
            and replay_actions(task_id, initial_state, actions)
        ):
            output["outcome_reward"] = 1.0
        output["acc_reward"] = output["outcome_reward"]
        output["total_reward"] = (
            output["format_reward"] + output["outcome_reward"]
        )
        return output

    def _log_turn(
        self,
        *,
        infer_request: RolloutInferRequest,
        model_response: str,
        tool_call: Optional[Dict[str, Any]],
        tool_result: Optional[Dict[str, Any]],
        continuation_prompt: Optional[str],
        new_images: List[str],
        current_turn: int,
    ) -> None:
        if not self._traj_log_dir:
            return
        sample_id = self._get_sample_id(infer_request)
        data = infer_request.data_dict or {}
        if sample_id not in self._trajectories:
            self._trajectories[sample_id] = {
                "initial_messages": [
                    {"role": message["role"], "content": message["content"]}
                    for message in (infer_request.messages or [])
                    if message.get("role") != "assistant"
                ],
                "initial_images": list(infer_request.images or []),
                "turns": [],
            }
        self._trajectories[sample_id]["turns"].append(
            {
                "turn": current_turn,
                "model_response": model_response,
                "tool_call": tool_call,
                "tool_result": tool_result,
                "continuation_prompt": continuation_prompt,
                "new_images": list(new_images),
                "full_conversation": list(
                    data.get("session_messages") or []
                ),
            }
        )

    def _current_training_step(self) -> int:
        try:
            from grpo_filtered_trainer import CURRENT_STEP as module_step
        except Exception:
            module_step = 0
        try:
            return int(os.environ.get("SPAGENT_CURRENT_STEP", module_step))
        except ValueError:
            return int(module_step or 0)

    def _flush_trajectory(
        self,
        infer_request: RolloutInferRequest,
        final_response: str,
        current_turn: int,
    ) -> None:
        if not self._traj_log_dir:
            return
        sample_id = self._get_sample_id(infer_request)
        data = infer_request.data_dict or {}
        trajectory = self._trajectories.pop(sample_id, None)
        if trajectory is None:
            trajectory = {
                "initial_messages": [
                    {"role": message["role"], "content": message["content"]}
                    for message in (infer_request.messages or [])
                    if message.get("role") != "assistant"
                ],
                "initial_images": list(infer_request.images or []),
                "turns": [],
            }
        session_messages = data.get("session_messages")
        if session_messages is not None:
            session_messages.append(
                {"role": "assistant", "content": final_response}
            )
        trajectory["turns"].append(
            {
                "turn": current_turn,
                "model_response": final_response,
                "tool_call": None,
                "tool_result": None,
                "continuation_prompt": None,
                "new_images": [],
                "is_final": True,
                "full_conversation": list(session_messages or []),
            }
        )
        state = data.get("_grid_puzzle") or {}
        rewards = self._compute_rewards(
            final_response,
            state.get("task_id"),
            state.get("initial_state"),
        )
        summary = {
            "global_step": self._current_training_step(),
            "rewards": rewards,
            "extracted_answer": rewards["extracted_answer"],
            "total_turns": current_turn,
            "task_id": state.get("task_id"),
            "final_environment": {
                "actions": list(state.get("actions") or []),
                "done": bool(state.get("done")),
                "success": bool(state.get("success")),
                "state": state.get("state"),
            },
        }
        summary.update(trajectory)

        step_dir = os.path.join(
            self._traj_log_dir, f"step{summary['global_step']}"
        )
        try:
            os.makedirs(step_dir, exist_ok=True)
        except OSError:
            step_dir = self._traj_log_dir
        self._traj_step_counter += 1
        path = os.path.join(
            step_dir,
            f"traj_r{self._traj_rank}_{self._traj_step_counter:06d}_"
            f"{sample_id}.json",
        )
        try:
            with open(path, "w", encoding="utf-8") as handle:
                json.dump(summary, handle, indent=2, default=str)
        except Exception as exc:
            logger.warning(f"Failed to write grid-puzzle trajectory: {exc}")

    def check_finished(
        self,
        infer_request: RolloutInferRequest,
        response_choice: ChatCompletionResponseChoice,
        current_turn: int,
    ) -> bool:
        state = self._state(infer_request)
        content = response_choice.message.content or ""
        if "<answer>" in content and "</answer>" in content:
            self._flush_trajectory(infer_request, content, current_turn)
            return True
        if state.get("done"):
            self._flush_trajectory(infer_request, content, current_turn)
            return True
        finished = super().check_finished(
            infer_request, response_choice, current_turn
        )
        if finished:
            self._flush_trajectory(infer_request, content, current_turn)
        return finished

    def step(
        self,
        infer_request: RolloutInferRequest,
        response_choice: ChatCompletionResponseChoice,
        current_turn: int,
    ) -> Dict[str, Any]:
        rollout_state = self._state(infer_request)
        task_id = rollout_state["task_id"]
        content = response_choice.message.content or ""
        new_images: List[str] = []
        tool_call: Optional[Dict[str, Any]] = None
        tool_result: Optional[Dict[str, Any]] = None

        match = TOOL_CALL_RE.search(content)
        if not match:
            body_text = (
                "No <tool_call> found. Call the move tool with exactly one "
                "direction, or finalize with "
                "<answer>full direction sequence</answer>."
            )
        else:
            try:
                tool_call = json.loads(match.group(1))
            except json.JSONDecodeError as exc:
                tool_call = {
                    "_raw": match.group(1),
                    "_parse_error": str(exc),
                }
                body_text = (
                    "Malformed tool JSON. Use exactly:\n"
                    '<tool_call>{"name": "move", "arguments": '
                    '{"direction": "Down"}}</tool_call>'
                )
            else:
                if not isinstance(tool_call, dict):
                    tool_result = {
                        "success": False,
                        "error": "tool_call_must_be_object",
                    }
                    body_text = (
                        "Malformed tool call: the JSON value must be an object."
                    )
                else:
                    name = tool_call.get("name")
                    arguments = tool_call.get("arguments") or {}
                    if name != "move":
                        tool_result = {
                            "success": False,
                            "error": f"unknown_tool:{name}",
                        }
                        body_text = (
                            f"Unknown tool {name!r}. Only `move` is available."
                        )
                    elif not isinstance(arguments, dict):
                        tool_result = {
                            "success": False,
                            "error": "arguments_must_be_object",
                        }
                        body_text = (
                            "Malformed move arguments: `arguments` must be "
                            "a JSON object."
                        )
                    else:
                        direction = arguments.get("direction", "")
                        outcome = step_state(
                            task_id, rollout_state["state"], direction
                        )
                        tool_result = dict(outcome.tool_result)
                        body_text = outcome.body_text
                        if outcome.changed:
                            rollout_state["actions"].append(direction)
                            rollout_state["done"] = outcome.done
                            rollout_state["success"] = outcome.success
                            image_path = self.tool_img_dir / (
                                f"{self._get_sample_id(infer_request)}_"
                                f"t{current_turn:03d}.png"
                            )
                            try:
                                render_state(
                                    task_id,
                                    rollout_state["state"],
                                    image_path,
                                )
                                new_images.append(str(image_path))
                                tool_result["output_path"] = str(image_path)
                            except Exception as exc:
                                logger.warning(
                                    f"Grid-puzzle render failed: {exc}"
                                )

        if rollout_state.get("done"):
            body_text += (
                "\n\nThe puzzle is solved. Output the full executed direction "
                "sequence as <answer>Direction1 Direction2 ...</answer>."
            )

        all_images = list(infer_request.images or []) + new_images
        labelled = [
            (
                "initial state" if index == 0 else f"after step {index}",
                path,
            )
            for index, path in enumerate(all_images)
        ]
        continuation_prompt = create_tool_response(body_text, labelled)

        data = infer_request.data_dict or {}
        session_messages = data.get("session_messages")
        if session_messages is not None:
            session_messages.append(
                {"role": "assistant", "content": content}
            )
        self._log_turn(
            infer_request=infer_request,
            model_response=content,
            tool_call=tool_call,
            tool_result=tool_result,
            continuation_prompt=continuation_prompt,
            new_images=new_images,
            current_turn=current_turn,
        )
        if session_messages is not None:
            session_messages.append(
                {"role": "user", "content": continuation_prompt}
            )

        next_messages = (
            list(session_messages)
            if session_messages is not None
            else [{"role": "user", "content": continuation_prompt}]
        )
        new_request = RolloutInferRequest(
            messages=next_messages,
            images=all_images,
            audios=getattr(infer_request, "audios", None),
            videos=getattr(infer_request, "videos", None),
            tools=getattr(infer_request, "tools", None),
            objects=getattr(infer_request, "objects", None),
            data_dict=infer_request.data_dict,
        )
        return {
            "infer_request": new_request,
            "rollout_infos": {
                "task_id": task_id,
                "gp_actions": list(rollout_state["actions"]),
                "gp_done": rollout_state["done"],
                "gp_success": rollout_state["success"],
                "num_turns": current_turn,
            },
        }


multi_turns["grid_puzzle_scheduler"] = GridPuzzleScheduler