#!/usr/bin/env python3
"""Offline NanoClaw mask-candidate and positive-advantage analysis.

The script reads saved ``conversation_history.json`` files and the reward
records written under ``step_N/_reward_logs``.  It does not load a model, start
Ray/vLLM, call a verifier, or modify the old rollout directories.

For every step it reports eight primary quantities:

  1. candidate turns for each of four bad-turn types;
  2. candidate turns whose group-score advantage is positive for each type.

Token counterparts are emitted as additional columns and plotted as well.
The positive-advantage decision is reconstructed from the saved final reward
score within each prompt/task group.  If the historical run used KL-in-reward,
the exact token-level KL contribution was not saved in conversation history;
the output therefore labels this reconstruction as ``positive_by_group_score``
and reports missing/incomplete groups explicitly.
"""

from __future__ import annotations

import argparse
import csv
import concurrent.futures
import json
import re
import sys
from collections import defaultdict
from dataclasses import dataclass, field
from pathlib import Path
from statistics import fmean
from typing import Any

try:
    import orjson  # type: ignore
except ImportError:
    orjson = None


REASONS = (
    "looping_response",
    "budget_exhausted_last_turn",
    "duplicate_tool_result_turn",
    "error_tool_result_turn",
)
TERMINATION_REASONS = {"max_assistant_response_tokens", "max_response_tokens"}
STEP_RE = re.compile(r"(?:^|/)step_(\d+)(?:/|$)")
RESULT_DIR_RE = re.compile(r"^(?P<task>.+)_sample_(?P<sample>\d+)(?:_[A-Za-z0-9]+)?$")


@dataclass
class Sample:
    history_path: Path
    result_dir: Path
    step: int | None
    task_id: str
    rollout_n: int | None
    payload: dict[str, Any]
    candidate_turns: dict[str, int] = field(default_factory=dict)
    candidate_tokens: dict[str, int] = field(default_factory=dict)
    score: float | None = None
    score_source: str | None = None
    group_mean: float | None = None
    group_advantage: float | None = None
    positive_by_group_score: bool | None = None
    group_complete: bool = False


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Analyze saved NanoClaw mask candidates by step.")
    parser.add_argument("workplace_root", type=Path, help="nanoclaw_temp_workplace... root")
    parser.add_argument("--output-dir", type=Path, default=None, help="Defaults to <root>/mask_analysis")
    parser.add_argument(
        "--history-name",
        "--trajectory-name",
        dest="history_name",
        default="conversation_history.json",
        help="Saved event file to scan (default: conversation_history.json; trajectory.json is also supported)",
    )
    parser.add_argument(
        "--expected-group-size",
        type=int,
        default=None,
        help="Expected GRPO samples per prompt, e.g. 8. Incomplete groups are not used for positive classification.",
    )
    parser.add_argument(
        "--workers",
        type=int,
        default=8,
        help="Parallel history readers (default: 8; use 2-4 on a slow shared filesystem).",
    )
    parser.add_argument("--no-plot", action="store_true", help="Write CSV/JSON only.")
    return parser.parse_args()


def load_json(path: Path) -> dict[str, Any] | None:
    try:
        raw = path.read_bytes()
        value = orjson.loads(raw) if orjson is not None else json.loads(raw)
    except (OSError, UnicodeDecodeError, json.JSONDecodeError):
        return None
    return value if isinstance(value, dict) else None


def number(value: Any) -> float | None:
    if isinstance(value, bool):
        return None
    try:
        result = float(value)
    except (TypeError, ValueError):
        return None
    return result if result == result else None


def integer(*values: Any) -> int | None:
    for value in values:
        if isinstance(value, bool):
            continue
        try:
            return int(value)
        except (TypeError, ValueError):
            continue
    return None


def events_from_history(payload: dict[str, Any]) -> list[dict[str, Any]]:
    events = payload.get("events")
    if isinstance(events, list):
        return [event for event in events if isinstance(event, dict)]
    nested = payload.get("conversation_history")
    if isinstance(nested, dict) and isinstance(nested.get("events"), list):
        return [event for event in nested["events"] if isinstance(event, dict)]
    return []


def infer_step(path: Path, payload: dict[str, Any]) -> int | None:
    match = STEP_RE.search(path.as_posix())
    if match:
        return int(match.group(1))
    for container_key in ("rollout", "workspace"):
        container = payload.get(container_key)
        if isinstance(container, dict):
            value = integer(container.get("step"), container.get("rollout_step"))
            if value is not None:
                return value
    return integer(payload.get("rollout_step"), payload.get("step"))


def result_dir_and_identity(history_path: Path, payload: dict[str, Any]) -> tuple[Path, str, int | None]:
    result_dir = history_path.parent
    task_id = payload.get("task_id")
    rollout_n = integer(payload.get("rollout_n"), payload.get("rollout_sample_index"))
    match = RESULT_DIR_RE.match(result_dir.name)
    if match:
        task_id = task_id or match.group("task")
        rollout_n = rollout_n if rollout_n is not None else int(match.group("sample"))
    if not isinstance(task_id, str) or not task_id:
        task_id = result_dir.name
    return result_dir, task_id, rollout_n


def event_turn(event: dict[str, Any]) -> int | None:
    return integer(event.get("assistant_turn"), event.get("turn"))


def assistant_events(events: list[dict[str, Any]]) -> dict[int, dict[str, Any]]:
    result: dict[int, dict[str, Any]] = {}
    for event in events:
        if event.get("type") == "assistant":
            turn = event_turn(event)
            if turn is not None:
                result[turn] = event
    return result


def assistant_tokens(event: dict[str, Any] | None) -> int:
    if not isinstance(event, dict):
        return 0
    explicit = integer(event.get("token_count"))
    if explicit is not None and explicit >= 0:
        return explicit
    start = integer(event.get("response_start"))
    end = integer(event.get("response_end"))
    return max(0, end - start) if start is not None and end is not None else 0


def text_parts(value: Any) -> list[str]:
    if isinstance(value, str):
        return [value]
    if isinstance(value, list):
        result: list[str] = []
        for item in value:
            result.extend(text_parts(item))
        return result
    if isinstance(value, dict):
        result: list[str] = []
        for key in ("text", "content"):
            if key in value:
                result.extend(text_parts(value[key]))
        return result
    return []


def is_error_tool_result(event: dict[str, Any]) -> bool:
    response = event.get("response")
    content = response.get("content") if isinstance(response, dict) else response
    if any(re.match(r"^\s*error(?:\b|\s*:)", text, re.IGNORECASE) for text in text_parts(content)):
        return True
    result = event.get("result")
    if not isinstance(result, dict):
        return False
    error_value = result.get("error")
    if error_value is not None and error_value is not False and error_value != "":
        return True
    status = result.get("status")
    return isinstance(status, str) and status.strip().lower() in {"error", "failed", "failure"}


def canonical_key(value: Any) -> str:
    try:
        return json.dumps(value, ensure_ascii=False, sort_keys=True, separators=(",", ":"), default=repr)
    except (TypeError, ValueError):
        return repr(value)


def duplicate_turns(events: list[dict[str, Any]]) -> set[int]:
    seen: set[str] = set()
    result: set[int] = set()
    for event in events:
        if event.get("type") != "tool":
            continue
        key = canonical_key({key: event.get(key) for key in ("tool", "arguments", "response", "result")})
        turn = event_turn(event)
        if key in seen and turn is not None:
            result.add(turn)
        seen.add(key)
    return result


def candidate_counts(payload: dict[str, Any]) -> tuple[dict[str, int], dict[str, int]]:
    events = events_from_history(payload)
    assistants = assistant_events(events)
    turns: dict[str, set[int]] = {reason: set() for reason in REASONS}

    for turn, event in assistants.items():
        repeats = integer(event.get("looping_repeat_count"), event.get("repeat_count")) or 0
        if repeats > 0 or event.get("looping_response_mask_candidate") is True:
            turns["looping_response"].add(turn)

    termination = payload.get("termination_reason")
    if not isinstance(termination, str) and isinstance(payload.get("summary"), dict):
        termination = payload["summary"].get("termination_reason")
    if termination in TERMINATION_REASONS and assistants:
        turns["budget_exhausted_last_turn"].add(max(assistants))

    turns["duplicate_tool_result_turn"] = duplicate_turns(events)
    for event in events:
        if event.get("type") == "tool" and is_error_tool_result(event):
            turn = event_turn(event)
            if turn is not None:
                turns["error_tool_result_turn"].add(turn)

    token_counts = {
        reason: sum(assistant_tokens(assistants.get(turn)) for turn in reason_turns)
        for reason, reason_turns in turns.items()
    }
    return {reason: len(reason_turns) for reason, reason_turns in turns.items()}, token_counts


def score_from_obj(obj: dict[str, Any]) -> tuple[float | None, str | None]:
    # Training reward logs contain the final reward under score. Prefer it over
    # verifier-only score_ratio because it includes configured bonuses/penalties.
    for key in ("score", "reward_score", "nanoclaw_score"):
        value = number(obj.get(key))
        if value is not None:
            return value, key
    summary = obj.get("score_summary")
    if isinstance(summary, dict):
        for key in ("score", "score_ratio"):
            value = number(summary.get(key))
            if value is not None:
                return value, f"score_summary.{key}"
    return None, None


def build_reward_index(root: Path) -> dict[str, list[tuple[float, str, Path]]]:
    index: dict[str, list[tuple[float, str, Path]]] = defaultdict(list)
    reward_paths: list[Path] = []
    for step_dir in root.glob("step_*"):
        reward_dir = step_dir / "_reward_logs"
        if reward_dir.is_dir():
            reward_paths.extend(reward_dir.glob("*.reward.json"))
    for path in sorted(reward_paths):
        obj = load_json(path)
        if not obj:
            continue
        score, source = score_from_obj(obj)
        result_dir = obj.get("result_dir")
        if score is None or not isinstance(result_dir, str):
            continue
        index[Path(result_dir).name].append((score, f"reward_log.{source}", path))
    return index


def load_sample_score(sample: Sample, reward_index: dict[str, list[tuple[float, str, Path]]]) -> None:
    result_name = sample.result_dir.name
    candidates = reward_index.get(result_name, [])
    if candidates:
        sample.score, sample.score_source, _ = candidates[-1]
        return

    # Useful when the run was rescored after training or reward logs were moved.
    for filename in ("score_summary.json", "verifier_result.json"):
        obj = load_json(sample.result_dir / filename)
        if obj:
            sample.score, sample.score_source = score_from_obj(obj)
            if sample.score is not None:
                return
    for container_key in ("score_summary", "verifier"):
        obj = sample.payload.get(container_key)
        if isinstance(obj, dict):
            sample.score, sample.score_source = score_from_obj(obj)
            if sample.score is not None:
                return


def assign_group_advantages(samples: list[Sample], expected_group_size: int | None) -> dict[str, int]:
    groups: dict[tuple[int | None, str], list[Sample]] = defaultdict(list)
    for sample in samples:
        groups[(sample.step, sample.task_id)].append(sample)
    diagnostics = {"groups": len(groups), "complete_groups": 0, "incomplete_groups": 0, "missing_score_samples": 0}

    for members in groups.values():
        scores = [sample.score for sample in members]
        complete = all(score is not None for score in scores)
        if expected_group_size is not None and len(members) != expected_group_size:
            complete = False
        if not complete:
            diagnostics["incomplete_groups"] += 1
            diagnostics["missing_score_samples"] += sum(score is None for score in scores)
            for sample in members:
                sample.group_complete = False
            continue

        diagnostics["complete_groups"] += 1
        numeric_scores = [float(score) for score in scores if score is not None]
        # GRPO with a singleton group uses a zero baseline in the reference
        # implementation; otherwise it uses the group mean.  Sign is unchanged
        # by positive std normalization.
        baseline = 0.0 if len(numeric_scores) == 1 else fmean(numeric_scores)
        for sample in members:
            assert sample.score is not None
            sample.group_complete = True
            sample.group_mean = baseline
            sample.group_advantage = sample.score - baseline
            sample.positive_by_group_score = sample.group_advantage > 0.0

    return diagnostics


def find_history_paths(root: Path, history_name: str) -> list[Path]:
    paths: list[Path] = []
    for step_dir in root.glob("step_*"):
        if step_dir.is_dir():
            paths.extend(step_dir.glob(f"*/{history_name}"))
    if paths:
        return sorted(path for path in paths if path.is_file())
    # Compatibility fallback for older/non-canonical workplace layouts.
    return sorted(path for path in root.rglob(history_name) if path.is_file())


def parse_history_sample(path: Path) -> Sample | None:
    payload = load_json(path)
    if payload is None:
        return None
    result_dir, task_id, rollout_n = result_dir_and_identity(path, payload)
    turn_counts, token_counts = candidate_counts(payload)
    return Sample(
        history_path=path,
        result_dir=result_dir,
        step=infer_step(path, payload),
        task_id=task_id,
        rollout_n=rollout_n,
        payload=payload,
        candidate_turns=turn_counts,
        candidate_tokens=token_counts,
    )


def scan(root: Path, history_name: str, expected_group_size: int | None, workers: int) -> tuple[list[Sample], dict[str, int]]:
    histories = find_history_paths(root, history_name)
    reward_index = build_reward_index(root)
    samples: list[Sample] = []
    malformed = 0
    worker_count = max(1, int(workers))
    if worker_count == 1 or len(histories) <= 1:
        parsed_iter = (parse_history_sample(path) for path in histories)
        executor_context = None
    else:
        executor_context = concurrent.futures.ThreadPoolExecutor(max_workers=worker_count)
        parsed_iter = executor_context.map(parse_history_sample, histories)
    try:
        for file_index, sample in enumerate(parsed_iter, start=1):
            if file_index % 500 == 0 or file_index == len(histories):
                print(f"[scan] parsed {file_index}/{len(histories)} histories", file=sys.stderr, flush=True)
            if sample is None:
                malformed += 1
                continue
            load_sample_score(sample, reward_index)
            # Candidate counts and score metadata are retained; the full JSON
            # event payload is no longer needed after this point.
            sample.payload = {}
            samples.append(sample)
    finally:
        if executor_context is not None:
            executor_context.shutdown(wait=True)
    diagnostics = {
        "history_files": len(histories),
        "loaded": len(samples),
        "malformed": malformed,
        "reward_records": sum(map(len, reward_index.values())),
        "workers": worker_count,
        "orjson": int(orjson is not None),
    }
    diagnostics.update(assign_group_advantages(samples, expected_group_size))
    return samples, diagnostics


def aggregate_rows(samples: list[Sample]) -> list[dict[str, Any]]:
    grouped: dict[int | None, list[Sample]] = defaultdict(list)
    for sample in samples:
        grouped[sample.step].append(sample)
    rows: list[dict[str, Any]] = []
    for step in sorted(grouped, key=lambda value: (value is None, value if value is not None else 0)):
        members = grouped[step]
        row: dict[str, Any] = {"step": "unknown" if step is None else step, "samples": len(members)}
        for reason in REASONS:
            row[f"{reason}_candidate_turns"] = sum(sample.candidate_turns[reason] for sample in members)
            row[f"{reason}_candidate_tokens"] = sum(sample.candidate_tokens[reason] for sample in members)
            positive_members = [sample for sample in members if sample.positive_by_group_score is True]
            row[f"{reason}_positive_masked_turns"] = sum(sample.candidate_turns[reason] for sample in positive_members)
            row[f"{reason}_positive_masked_tokens"] = sum(sample.candidate_tokens[reason] for sample in positive_members)
        row["scored_samples"] = sum(sample.score is not None for sample in members)
        row["positive_group_score_samples"] = sum(sample.positive_by_group_score is True for sample in members)
        row["incomplete_group_samples"] = sum(not sample.group_complete for sample in members)
        for reason in REASONS:
            row[f"{reason}_candidate_turns_per_sample"] = row[f"{reason}_candidate_turns"] / len(members) if members else 0.0
            row[f"{reason}_positive_masked_turns_per_sample"] = row[f"{reason}_positive_masked_turns"] / len(members) if members else 0.0
        rows.append(row)
    return rows


def write_csv(path: Path, rows: list[dict[str, Any]]) -> None:
    fields = list(rows[0].keys()) if rows else ["step", "samples"]
    with path.open("w", encoding="utf-8", newline="") as handle:
        writer = csv.DictWriter(handle, fieldnames=fields)
        writer.writeheader()
        writer.writerows(rows)


def write_sample_csv(path: Path, samples: list[Sample]) -> None:
    fields = ["step", "task_id", "rollout_n", "result_dir", "score", "score_source", "group_mean", "group_advantage", "positive_by_group_score", "group_complete"]
    for reason in REASONS:
        fields.extend((f"{reason}_candidate_turns", f"{reason}_candidate_tokens"))
    with path.open("w", encoding="utf-8", newline="") as handle:
        writer = csv.DictWriter(handle, fieldnames=fields)
        writer.writeheader()
        for sample in samples:
            row: dict[str, Any] = {
                "step": "unknown" if sample.step is None else sample.step,
                "task_id": sample.task_id,
                "rollout_n": sample.rollout_n,
                "result_dir": str(sample.result_dir),
                "score": sample.score,
                "score_source": sample.score_source,
                "group_mean": sample.group_mean,
                "group_advantage": sample.group_advantage,
                "positive_by_group_score": sample.positive_by_group_score,
                "group_complete": sample.group_complete,
            }
            for reason in REASONS:
                row[f"{reason}_candidate_turns"] = sample.candidate_turns[reason]
                row[f"{reason}_candidate_tokens"] = sample.candidate_tokens[reason]
            writer.writerow(row)


def make_plot(output_dir: Path, rows: list[dict[str, Any]]) -> Path | None:
    known = [row for row in rows if row["step"] != "unknown"]
    if not known:
        return None
    try:
        import matplotlib.pyplot as plt
    except ImportError:
        print("WARNING: matplotlib is unavailable; CSV/JSON were written without plots.", file=sys.stderr)
        return None
    colors = {"looping_response": "#d62728", "budget_exhausted_last_turn": "#ff7f0e", "duplicate_tool_result_turn": "#2ca02c", "error_tool_result_turn": "#1f77b4"}
    labels = {"looping_response": "looping", "budget_exhausted_last_turn": "budget exhausted", "duplicate_tool_result_turn": "duplicate tool", "error_tool_result_turn": "error tool"}
    steps = [int(row["step"]) for row in known]
    fig, axes = plt.subplots(2, 2, figsize=(15, 9), sharex="col", constrained_layout=True)
    for reason in REASONS:
        color, label = colors[reason], labels[reason]
        axes[0, 0].plot(steps, [row[f"{reason}_candidate_turns"] for row in known], marker="o", color=color, label=label)
        axes[0, 1].plot(steps, [row[f"{reason}_positive_masked_turns"] for row in known], marker="o", color=color, label=label)
        axes[1, 0].plot(steps, [row[f"{reason}_candidate_tokens"] for row in known], marker="o", color=color, label=label)
        axes[1, 1].plot(steps, [row[f"{reason}_positive_masked_tokens"] for row in known], marker="o", color=color, label=label)
    axes[0, 0].set_title("candidate bad-turns")
    axes[0, 1].set_title("positive group-score candidate turns")
    axes[1, 0].set_title("candidate tokens")
    axes[1, 1].set_title("positive group-score candidate tokens")
    for row_axes in axes:
        for axis in row_axes:
            axis.grid(True, alpha=0.3)
            axis.legend()
    axes[1, 0].set_xlabel("training step")
    axes[1, 1].set_xlabel("training step")
    plot_path = output_dir / "nanoclaw_mask_candidates_and_positive_by_step.png"
    fig.savefig(plot_path, dpi=160)
    plt.close(fig)
    return plot_path


def main() -> int:
    args = parse_args()
    root = args.workplace_root.expanduser().resolve()
    if not root.is_dir():
        print(f"ERROR: workplace root is not a directory: {root}", file=sys.stderr)
        return 2
    output_dir = (args.output_dir or root / "mask_analysis").expanduser().resolve()
    samples, diagnostics = scan(root, args.history_name, args.expected_group_size, args.workers)
    rows = aggregate_rows(samples)
    output_dir.mkdir(parents=True, exist_ok=True)
    summary_csv = output_dir / "nanoclaw_mask_8_metrics_by_step.csv"
    sample_csv = output_dir / "nanoclaw_mask_group_scores_and_candidates.csv"
    summary_json = output_dir / "nanoclaw_mask_8_metrics_by_step.json"
    write_csv(summary_csv, rows)
    write_sample_csv(sample_csv, samples)
    plot_path = None if args.no_plot else make_plot(output_dir, rows)
    summary_json.write_text(
        json.dumps(
            {
                "workplace_root": str(root),
                "history_name": args.history_name,
                "expected_group_size": args.expected_group_size,
                "advantage_reconstruction": "score - group_mean; singleton baseline=0; exact KL-in-reward advantage requires saved reward/advantage tensors",
                "diagnostics": diagnostics,
                "rows": rows,
            },
            ensure_ascii=False,
            indent=2,
        )
        + "\n",
        encoding="utf-8",
    )

    print(f"workplace root: {root}")
    print(f"history files: {diagnostics['history_files']}, loaded: {diagnostics['loaded']}, malformed: {diagnostics['malformed']}")
    print(f"history workers: {diagnostics['workers']}, orjson: {diagnostics['orjson']}")
    print(f"reward records: {diagnostics['reward_records']}, groups: {diagnostics['groups']}, complete groups: {diagnostics['complete_groups']}")
    print(f"incomplete groups: {diagnostics['incomplete_groups']}, missing-score samples: {diagnostics['missing_score_samples']}")
    print(f"summary CSV: {summary_csv}")
    print(f"group/sample CSV: {sample_csv}")
    print(f"summary JSON: {summary_json}")
    if plot_path:
        print(f"plot: {plot_path}")
    for row in rows:
        print(
            f"step={row['step']} samples={row['samples']} "
            + " ".join(
                f"{reason}={row[f'{reason}_candidate_turns']}/{row[f'{reason}_positive_masked_turns']} turns"
                for reason in REASONS
            )
        )
    return 0


if __name__ == "__main__":
    raise SystemExit(main())