自动研究式特征发现

from __future__ import annotations
 
import json
import os
import random
import textwrap
import urllib.request
from concurrent.futures import ThreadPoolExecutor
from pathlib import Path
from time import perf_counter
from typing import NamedTuple
 
import matplotlib
import matplotlib.pyplot as plt
import numpy as np
from catboost import CatBoostRegressor
from cooksafe import JsonCache, make_playground_link
from IPython.display import Markdown, display
from typesafe_sdk import Noul, NoulCriteria, Score, TypeSafeClient
 
matplotlib.use("Agg")  # headless render
 
TYPESAFE_MODEL = "jev-1.12"
FOLDS, REPEATS = 5, 3  # repeats steady the error at this sample size
CATBOOST = dict(
    iterations=400,
    depth=4,
    learning_rate=0.05,
    loss_function="RMSE",
    verbose=0,
    random_seed=0,
    thread_count=1,
    allow_writing_files=False,
)
 
client = TypeSafeClient(
    # keyless kernels replay the cache
    api_key=os.environ.get("TYPESAFE_API_KEY", "cache-only"),
    base_url=os.environ.get("TYPESAFE_ENDPOINT"),
    timeout=120.0,
)
json_cache = JsonCache(Path("json_cache.json"))
 
# ----------------------------------------------------------------- the specification
 
INTENSITY_LEVELS = [
    "Not present in this note at all",
    "Barely present - mentioned once, in passing",
    "Present at a moderate level",
    "Present strongly - the note dwells on it",
    "Dominant - the note is largely about this",
]
PRESENCE_CRITERIA = NoulCriteria(
    true="The note states this or clearly implies it",
    false="The note gives no indication of this",
)
 
# Asking for the score outright: ten quality bands, rescaled onto the 80-100 critic scale.
SCORE_LEVELS = [
    "Faulty or unpleasant - the note is mostly criticism",
    "Barely acceptable - drinkable, with nothing to recommend it",
    "Simple and sound - correct, plain, forgettable",
    "Pleasant everyday wine - some appeal, little depth",
    "Good - clear varietal character, well made",
    "Very good - balanced, with something to say",
    "Excellent - complex and structured",
    "Outstanding - depth and length, built to age",
    "Superb - among the best of its type",
    "Profound - the note treats it as exceptional",
]
 
# Structured output requires every property in `required`, so unused fields come back empty.
PROPOSAL_SCHEMA = {
    "type": "object",
    "properties": {
        "actions": {
            "type": "array",
            "items": {
                "type": "object",
                "properties": {
                    "op": {"type": "string", "enum": ["add", "revise", "drop"]},
                    "target": {"type": "string"},
                    "name": {"type": "string"},
                    "kind": {"type": "string", "enum": ["intensity", "presence"]},
                    "question": {"type": "string"},
                },
                "required": ["op", "target", "name", "kind", "question"],
                "additionalProperties": False,
            },
        }
    },
    "required": ["actions"],
    "additionalProperties": False,
}
 
PROPOSALS = 18  # actions the proposer may return per round
 
# The one string that knows this is about wine. Point it at your own label and text.
PROPOSER_TASK = f"""You are designing numeric features for a gradient-boosting model that
predicts the score a wine critic gave (an integer from 80 to 100) from the tasting note alone.
The model sees nothing but the features you design.
 
Return up to {PROPOSALS} actions. Each action is one of:
 
- {{"op": "add", "target": "", "name": ..., "kind": ..., "question": ...}}
  A new feature.
- {{"op": "revise", "target": <name of an existing feature>, "name": ..., "kind": ...,
  "question": ...}}
  Replace that feature's question with better wording. Use this when a feature measures the
  right thing badly: too narrow, too vague, or worded so nearly every note answers the same.
- {{"op": "drop", "target": <name of an existing feature>, "name": "", "kind": "intensity",
  "question": ""}}
  Remove a feature that is not earning its place.
 
`kind` is "intensity" for something with a degree, or "presence" for a yes/no fact.
`question` is what gets asked about one tasting note.
 
An "intensity" question is graded against this fixed five-level rubric, so word it so that the
levels make sense:
{chr(10).join(f"  {i}. {level}" for i, level in enumerate(INTENSITY_LEVELS))}
 
A "presence" question is answered as the probability that it is true of the note.
 
Good features can be judged from the note's own words, vary from note to note, and carry
information about quality that the other features do not. Reviewers describe structure, fruit,
oak, length, complexity, and drinkability, and they also signal quality through word choice."""
 
 
class Split(NamedTuple):
    """The rows, their labels, and which half the loop is allowed to read."""
 
    notes: list[str]
    scores: np.ndarray
    dev: np.ndarray
    test: np.ndarray
 
 
# ----------------------------------------------------------------- the data
 
WINEMAG_CSV = (
    "https://huggingface.co/datasets/GroNLP/ik-nlp-22_winemag/resolve/"
    "90eb39f35fc64e556fc17f06d4137a4a69ec3297/train.csv"
)
 
 
@json_cache
def load_slice(n_dev: int, n_test: int, seed: int) -> dict:
    """Fetch the pinned CSV and take a seeded sample of note + score, one row per note."""
    import csv
    import io
 
    request = urllib.request.Request(
        WINEMAG_CSV, headers={"User-Agent": "typesafe-cookbook/1.0"}
    )
    with urllib.request.urlopen(request, timeout=300) as response:
        text = response.read().decode()
    rows, seen = [], set()
    for row in csv.DictReader(io.StringIO(text)):  # a few notes repeat verbatim
        if not row["description"] or not row["points"] or row["description"] in seen:
            continue
        seen.add(row["description"])
        rows.append((row["description"], float(row["points"])))
    random.Random(seed).shuffle(rows)
    picked = rows[: n_dev + n_test]
    return {"notes": [r[0] for r in picked], "points": [r[1] for r in picked]}
 
 
def example_rows(split: Split, out_of_fold: np.ndarray | None, n: int) -> list[int]:
    """Select representative dev rows for a proposer round."""
    dev = split.dev
    if out_of_fold is None:
        ranked = dev[np.argsort(split.scores[dev], kind="stable")]
        return [int(ranked[round(q * (len(ranked) - 1))]) for q in np.linspace(0, 1, n)]
    error = np.abs(split.scores[dev] - out_of_fold)
    order = np.argsort(-error, kind="stable")
    worst = [int(dev[i]) for i in order[: n // 2]]
    best = [int(dev[i]) for i in order[len(order) - (n - n // 2) :]]
    return worst + best
 
 
def example_block(
    rows: list[int],
    split: Split,
    out_of_fold: np.ndarray | None,
    previous: np.ndarray | None = None,
) -> str:
    """Format selected rows for the proposer."""
    if out_of_fold is None:
        head = "Example notes, with the score each one was given:"
        body = [f"- scored {split.scores[r]:.0f}: {split.notes[r]}" for r in rows]
        return head + "\n" + "\n".join(body)
 
    head = (
        "Dev notes, worst-predicted first. The first half is where your current questions "
        "miss by the most and the second half is where they are already right, so what "
        "separates the halves is what the questions have not captured."
    )
    if previous is not None:
        head += (
            " Each line also carries what the previous round predicted, so you can see which "
            "notes your last batch of questions moved."
        )
    body = []
    for r in rows:
        line = f"- scored {split.scores[r]:.0f}, predicted {out_of_fold[r]:.1f}"
        if previous is not None:
            line += f" (last round {previous[r]:.1f})"
        body.append(f"{line}: {split.notes[r]}")
    return head + "\n" + "\n".join(body)
 
 
def load_split(n_dev: int, n_test: int, seed: int = 0) -> Split:
    # keyword, because the cache key is the function name plus how each argument was spelled
    data = load_slice(n_dev, n_test, seed=seed)
    return Split(
        notes=data["notes"],
        scores=np.array(data["points"]),
        dev=np.arange(n_dev),
        test=np.arange(n_dev, n_dev + n_test),
    )
 
 
# ----------------------------------------------------------------- step 1: propose
 
 
def proposal_prompt(examples: str, feedback: str, accepted: list[dict]) -> str:
    parts = [PROPOSER_TASK, "\n" + examples]
    if accepted:
        parts.append(
            "\nThe features you have now. `add` must not duplicate one of these; `revise` and "
            "`drop` refer to one by name:\n"
            + "\n".join(
                f"- {f['name']} ({f['kind']}): {f['question']}" for f in accepted
            )
        )
    if feedback:
        parts.append("\nHow the model did with those features:\n" + feedback)
    return "\n".join(parts)
 
 
@json_cache
def propose(model: str, round_index: int, prompt: str) -> dict:
    """One proposal call. Every number in `prompt` is rounded so a replay hits the cache."""
    if model.startswith("claude"):
        import anthropic
 
        response = anthropic.Anthropic(
            api_key=os.environ.get("ANTHROPIC_API_KEY", "cache-only")
        ).messages.create(
            model=model,
            max_tokens=16000,
            output_config={
                "effort": "medium",
                "format": {"type": "json_schema", "schema": PROPOSAL_SCHEMA},
            },
            messages=[{"role": "user", "content": prompt}],
        )
        body = next(block.text for block in response.content if block.type == "text")
        usage = [response.usage.input_tokens or 0, response.usage.output_tokens or 0]
    else:
        from openai import OpenAI
 
        response = OpenAI(
            api_key=os.environ.get("OPENAI_API_KEY", "cache-only")
        ).chat.completions.create(
            model=model,
            reasoning_effort="high",
            max_completion_tokens=16000,
            response_format={"type": "json_object"},
            messages=[
                {
                    "role": "user",
                    "content": prompt
                    + "\n\nReply with JSON matching this schema:\n"
                    + json.dumps(PROPOSAL_SCHEMA),
                }
            ],
        )
        body = response.choices[0].message.content
        usage = [response.usage.prompt_tokens, response.usage.completion_tokens]
    return {"actions": json.loads(body)["actions"][:PROPOSALS], "usage": usage}
 
 
def slug(name: str, taken: set[str]) -> str:
    """Names become question ids and column labels, so keep them plain and unique."""
    base = (
        "".join(c if c.isalnum() else "_" for c in name.lower()).strip("_") or "feature"
    )
    candidate, n = base, 2
    while candidate in taken:
        candidate, n = f"{base}_{n}", n + 1
    return candidate
 
 
def to_candidates(actions: list[dict], accepted: list[dict], round_index: int) -> tuple:
    """Split a round's actions into screenable candidates and a list of names to drop."""
    live = {f["name"] for f in accepted}
    drops = [a["target"] for a in actions if a["op"] == "drop" and a["target"] in live]
    replacing = {
        a["target"] for a in actions if a["op"] == "revise" and a["target"] in live
    }
    # a revision may keep the name it replaces, since that feature is on its way out
    taken, candidates = live - replacing, []
    for action in actions:
        if action["op"] == "drop":
            continue
        if action["op"] == "revise" and action["target"] not in live:
            continue  # a revision of something that is not there
        name = slug(action["name"], taken)
        taken.add(name)
        candidates.append(
            {
                "id": f"{name}@{round_index}",  # unique, so earlier rounds keep their columns
                "name": name,
                "kind": action["kind"],
                "question": action["question"],
                "replaces": action["target"] if action["op"] == "revise" else "",
            }
        )
    return candidates, drops
 
 
# ----------------------------------------------------------------- step 2: answer
 
 
def feature_questions(features: list[dict]) -> dict:
    questions = {}
    for feature in features:
        if feature["kind"] == "intensity":
            questions[feature["name"]] = Score(
                instructions=feature["question"], criteria=INTENSITY_LEVELS
            )
        else:
            questions[feature["name"]] = Noul(
                instructions=feature["question"], criteria=PRESENCE_CRITERIA
            )
    return questions
 
 
@json_cache
def answer(model: str, note: str, features_json: str) -> dict:
    """One request per note; every question of the round rides it. Keeps every probability."""
    features = json.loads(features_json)
    started = perf_counter()
    response = client.system_one(
        state=note, questions=feature_questions(features), model=model
    )
    raw = {}
    for feature in features:
        got = response.answers[feature["name"]]
        if feature["kind"] == "intensity":
            raw[feature["name"]] = [
                got.probabilities.get(i, 0.0) for i in range(len(INTENSITY_LEVELS))
            ]
        else:
            raw[feature["name"]] = [got.noul]
    return {
        "raw": raw,
        "seconds": round(perf_counter() - started, 2),
        "input_tokens": response.usage.input_tokens or 0,
        "output_tokens": response.usage.output_tokens or 0,
    }
 
 
def featurize(notes: list[str], features: list[dict]) -> dict:
    """Answer one question set for many notes: one request each, eight in flight."""
    payload = json.dumps(features, sort_keys=True)
    with ThreadPoolExecutor(max_workers=8) as pool:
        results = list(
            pool.map(lambda note: answer(TYPESAFE_MODEL, note, payload), notes)
        )
    return {
        f["name"]: np.array([r["raw"][f["name"]] for r in results], dtype=float)
        for f in features
    }
 
 
def encode(feature: dict, probabilities: np.ndarray, mode: str) -> list[tuple]:
    """Turn one question's probabilities into named columns."""
    name = feature["name"]
    if feature["kind"] == "presence":
        return [(name, probabilities[:, 0])]  # one number is all there is
    levels = np.arange(probabilities.shape[1])
    mean = probabilities @ levels
    if mode == "mean":
        return [(name, mean)]
    if mode == "mean_spread":
        variance = probabilities @ (levels**2) - mean**2
        return [(name, mean), (f"{name}_sd", np.sqrt(np.clip(variance, 0, None)))]
    return [(f"{name}_p{i}", probabilities[:, i]) for i in levels]
 
 
def design(features: list[dict], answers_for: dict, mode: str) -> tuple:
    """Stack every feature's columns into one matrix, plus a label per column."""
    columns, labels = [], []
    for feature in features:
        for label, column in encode(feature, answers_for[feature["id"]], mode):
            columns.append(column)
            labels.append(label)
    return np.column_stack(columns), labels
 
 
def plain(features: list[dict]) -> list[dict]:
    """What goes on the wire and into the cache key: no id, no bookkeeping."""
    return [
        {"name": f["name"], "kind": f["kind"], "question": f["question"]}
        for f in features
    ]
 
 
# ----------------------------------------------------------------- step 3: fit
 
 
def rmse(y: np.ndarray, p: np.ndarray) -> float:
    return float(np.sqrt(np.mean((y - p) ** 2)))
 
 
def spearman(a: np.ndarray, b: np.ndarray) -> float:
    """Rank correlation: does the model order the wines the way the critic did?"""
    ranks = (
        np.argsort(np.argsort(a)).astype(float),
        np.argsort(np.argsort(b)).astype(float),
    )
    return float(np.corrcoef(*ranks)[0, 1])
 
 
def folds(y: np.ndarray, k: int, seed: int) -> list[np.ndarray]:
    """Label-stratified k-fold: sort by the label with a seeded tiebreak, then deal off the top."""
    rng = np.random.default_rng(seed)
    order = np.lexsort((rng.random(len(y)), y))
    return [np.sort(order[i::k]) for i in range(k)]
 
 
def cross_validate(X: np.ndarray, y: np.ndarray) -> tuple[np.ndarray, float]:
    out_of_fold = np.zeros((REPEATS, len(y)))
    for repeat in range(REPEATS):
        for fold in folds(y, FOLDS, seed=repeat):
            train = np.setdiff1d(np.arange(len(y)), fold)
            model = CatBoostRegressor(**CATBOOST).fit(X[train], y[train])
            out_of_fold[repeat, fold] = model.predict(X[fold])
    scores = [rmse(y, out_of_fold[repeat]) for repeat in range(REPEATS)]
    return out_of_fold.mean(axis=0), float(np.mean(scores))
 
 
def importances(X: np.ndarray, y: np.ndarray) -> np.ndarray:
    return CatBoostRegressor(**CATBOOST).fit(X, y).get_feature_importance()
 
 
def paired_gain(y: np.ndarray, before: np.ndarray, after: np.ndarray) -> tuple:
    """Bootstrap the paired held-out RMSE change."""
    squared = ((y - before) ** 2, (y - after) ** 2)
    rng = np.random.default_rng(0)
    drawn = []
    for _ in range(2000):
        rows = rng.integers(0, len(y), len(y))
        drawn.append(
            np.sqrt(squared[1][rows].mean()) - np.sqrt(squared[0][rows].mean())
        )
    drawn = np.array(drawn)
    return (
        rmse(y, after) - rmse(y, before),
        float(np.percentile(drawn, 2.5)),
        float(np.percentile(drawn, 97.5)),
    )
 
 
def fit_predict(X: np.ndarray, split: Split) -> np.ndarray:
    model = CatBoostRegressor(**CATBOOST).fit(X[split.dev], split.scores[split.dev])
    return model.predict(X[split.test])
 
 
def fit_predict_text(split: Split) -> np.ndarray:
    """The reference arm: the same model, handed the note instead of the columns."""
    from catboost import Pool
 
    raw = np.array([[note] for note in split.notes], dtype=object)
    model = CatBoostRegressor(**CATBOOST).fit(
        Pool(raw[split.dev], split.scores[split.dev], text_features=[0])
    )
    return model.predict(Pool(raw[split.test], text_features=[0]))
 
 
def evaluate(
    features: list[dict], answers_for: dict, split: Split, mode: str
) -> tuple[np.ndarray, float]:
    """Cross-validated error on the dev rows for one candidate question set."""
    X, _ = design(features, answers_for, mode)
    return cross_validate(X[split.dev], split.scores[split.dev])
 
 
def swap_in(accepted: list[dict], feature: dict) -> list[dict] | None:
    """The accepted set with `feature` in place of the one it revises, or None if it is gone."""
    at = next(
        (i for i, f in enumerate(accepted) if f["name"] == feature["replaces"]), None
    )
    if at is None:
        return None
    trial = list(accepted)
    trial[at] = {k: feature[k] for k in ("id", "name", "kind", "question")}
    return trial
 
 
def try_change(
    trial: list[dict],
    accepted: list[dict],
    cv: float,
    answers_for: dict,
    split: Split,
    mode: str,
    tolerance: float,
) -> tuple[list[dict], float, str, bool]:
    """Refit with the change and keep it only if the dev error improves. No API calls."""
    _, cv_trial = evaluate(trial, answers_for, split, mode)
    if cv_trial <= cv + tolerance:
        return trial, cv_trial, f"CV {cv:.3f} -> {cv_trial:.3f}", True
    return accepted, cv, f"would cost {cv_trial - cv:+.3f}", False
 
 
def owner_of(label: str, features: list[dict]) -> dict:
    """Which feature a column label belongs to - encodings suffix the name."""
    exact = next((f for f in features if f["name"] == label), None)
    if exact:
        return exact
    return next(f for f in features if label.startswith(f["name"] + "_"))
 
 
def importance_per_feature(
    features: list[dict], labels: list[str], column_importances: np.ndarray
) -> dict:
    """Sum each question's CatBoost column importances.
 
    Intensity questions can produce multiple model columns. Combining their normalized
    importances gives one percentage share per question.
    """
    total = {f["name"]: 0.0 for f in features}
    for label, column_importance in zip(labels, column_importances):
        total[owner_of(label, features)["name"]] += float(column_importance)
    return total
 
 
def feedback_for(
    history: list[float],
    accepted: list[dict],
    answers_for: dict,
    split: Split,
    mode: str,
    out_of_fold: np.ndarray,
    previous: np.ndarray | None,
) -> str:
    """The scoreboard the next proposal call reads. The notes themselves arrive separately,
    through `example_block`. Numbers are rounded before they enter the prompt."""
    X, labels = design(accepted, answers_for, mode)
    dev, scores = split.dev, split.scores
    by_name = importance_per_feature(accepted, labels, importances(X[dev], scores[dev]))
 
    lines = ["Cross-validated RMSE in points so far, lower is better:"]
    lines += [f"  round {i + 1}: {v:.2f}" for i, v in enumerate(history)]
    if previous is not None:
        now, before = np.abs(scores[dev] - out_of_fold), np.abs(scores[dev] - previous)
        better, worse = int((now < before - 0.1).sum()), int((now > before + 0.1).sum())
        lines.append(
            f"\nAgainst the previous round, {better} of the {len(dev)} dev notes are now "
            f"predicted better by more than 0.1 points and {worse} are predicted worse."
        )
    lines.append(
        "\nYour features, with importance as a percentage of the total and the spread of the "
        "column across the dev rows. Low importance or low spread means the question is not "
        "doing much; revise or drop it."
    )
    for feature in sorted(accepted, key=lambda f: -by_name.get(f["name"], 0.0)):
        column = encode(feature, answers_for[feature["id"]], mode)[0][1]
        lines.append(
            f"  {feature['name']} ({feature['kind']}): "
            f"{by_name.get(feature['name'], 0.0):.1f}% importance, "
            f"spread {column[dev].std():.2f}"
        )
    return "\n".join(lines)
 
 
# ----------------------------------------------------------------- the loop itself
 
 
class Discovery(NamedTuple):
    """Artifacts returned by the discovery loop."""
 
    accepted: list[dict]  # the question set it ended with
    answers_for: dict  # feature id -> (rows x levels) probabilities
    snapshots: list[list[dict]]  # the set as it stood at the end of each round
    history: list[float]  # dev CV error after each round
    batches: list[tuple]  # what each round sent, for the request table
    journal: list[tuple]  # every action and what became of it
 
 
def run_loop(
    split: Split,
    proposer: str,
    rounds: int,
    examples: int,
    mode: str,
    min_spread: float,
    tolerance: float,
) -> Discovery:
    """Run the propose, answer, fit, and feedback loop."""
    shown = example_rows(split, None, examples)  # round 1 has nothing predicted yet
    out_of_fold = previous = None
    got_from = Discovery([], {}, [], [], [], [])
    accepted, answers_for = got_from.accepted, got_from.answers_for
    snapshots, history = got_from.snapshots, got_from.history
    batches, journal = got_from.batches, got_from.journal
    feedback = ""
 
    for round_index in range(1, rounds + 1):
        block = example_block(shown, split, out_of_fold, previous)
        actions = propose(
            proposer, round_index, proposal_prompt(block, feedback, accepted)
        )["actions"]
        keep, drops = to_candidates(actions, accepted, round_index)
 
        if keep:  # one request per row, carrying every question this round proposed
            batches.append((round_index, plain(keep)))
            answers = featurize(split.notes, plain(keep))
            for feature in keep:
                answers_for[feature["id"]] = answers[feature["name"]]
 
        for (
            feature
        ) in keep:  # an add goes in; importance says later whether it earned it
            if feature["replaces"]:
                continue
            column = encode(feature, answers_for[feature["id"]], mode)[0][1]
            flat = float(column[split.dev].std()) < min_spread
            journal.append(
                (round_index, "flat" if flat else "add", feature["name"], "")
            )
            if not flat:
                accepted.append(
                    {k: feature[k] for k in ("id", "name", "kind", "question")}
                )
 
        _, cv = evaluate(accepted, answers_for, split, mode)
        trial_args = (answers_for, split, mode, tolerance)
 
        for feature in [f for f in keep if f["replaces"]]:  # every revision is tried
            trial = swap_in(accepted, feature)
            if trial is None:  # it revises something an earlier round already dropped
                journal.append(
                    (round_index, "stale", feature["name"], "target is gone")
                )
                continue
            accepted[:], cv, note, took = try_change(trial, accepted, cv, *trial_args)
            what = "revise" if took else "reject"
            journal.append(
                (
                    round_index,
                    what,
                    feature["name"],
                    f"was {feature['replaces']}, {note}",
                )
            )
 
        for name in drops:  # and so is every drop
            trial = [f for f in accepted if f["name"] != name]
            if not trial:
                continue
            accepted[:], cv, note, took = try_change(trial, accepted, cv, *trial_args)
            journal.append((round_index, "drop" if took else "keep", name, note))
 
        previous, (out_of_fold, cv) = (
            out_of_fold,
            evaluate(accepted, answers_for, split, mode),
        )
        history.append(cv)
        snapshots.append(list(accepted))
        feedback = feedback_for(
            history, accepted, answers_for, split, mode, out_of_fold, previous
        )
        # next round reads the rows these questions get most wrong, and as many they get right
        shown = example_rows(split, out_of_fold, examples)
        report(round_index, keep, drops, journal, accepted, cv)
 
    return got_from
 
 
def report(
    round_index: int,
    keep: list[dict],
    drops: list[str],
    journal: list[tuple],
    accepted: list[dict],
    cv: float,
) -> None:
    """One block per round: the counts, the names it added, then everything with a number."""
    revised = sum(1 for f in keep if f["replaces"])
    print(
        f"round {round_index}: {len(keep) - revised} add, {revised} revise, "
        f"{len(drops)} drop"
    )
    this_round = [j for j in journal if j[0] == round_index]
    added = [name for _, what, name, _ in this_round if what == "add"]
    if added:
        print(
            textwrap.fill(
                ", ".join(added),
                88,
                initial_indent="  added  ",
                subsequent_indent=" " * 10,
            )
        )
    for _, what, name, note in this_round:  # everything carrying a number of its own
        if what != "add":
            print(f"  {what:<7}{name:<34}{note}")
    print(f"  -> {len(accepted)} features, dev CV RMSE {cv:.3f}\n")
 
 
# ----------------------------------------------------------------- asking for the score
 
 
@json_cache
def ask_score(model: str, note: str) -> dict:
    """One `Score` over ten quality bands, read as a level and rescaled to 80-100."""
    response = client.system_one(
        state=note,
        questions={
            "quality": Score(
                instructions=(
                    "Judging only by what this tasting note says, how good is the wine?"
                ),
                criteria=SCORE_LEVELS,
            )
        },
        model=model,
    )
    got = response.answers["quality"]
    top = len(SCORE_LEVELS) - 1
    expected = sum(k * v for k, v in got.probabilities.items())
    return {
        # level 0 is the bottom of the critic's scale, level 9 the top
        "expected": 80.0 + 20.0 * expected / top,
        "picked": 80.0 + 20.0 * got.score / top,
        "input_tokens": response.usage.input_tokens or 0,
        "output_tokens": response.usage.output_tokens or 0,
    }
 
 
# ----------------------------------------------------------------- charts
 
SURFACE, INK, INK2, MUTED = "#fcfcfb", "#0b0b0b", "#52514e", "#898781"
GRID, AXIS, BLUE, ORANGE = "#e1e0d9", "#c3c2b7", "#2a78d6", "#eb6834"
 
 
def style(ax) -> None:
    ax.set_facecolor(SURFACE)
    for side in ("top", "right"):
        ax.spines[side].set_visible(False)
    for side in ("left", "bottom"):
        ax.spines[side].set_color(AXIS)
    ax.tick_params(colors=MUTED, labelcolor=INK2, labelsize=9)
    ax.set_axisbelow(True)
 
 
def polarity(feature: dict, answers_for: dict, split: Split) -> float:
    """Rank correlation between a question's answer and the critic score, on the dev rows.
 
    Positive means a higher answer goes with a better review, negative the opposite. It is
    what orders the rows of the feature map, so the map reads as a gradient that flips.
    """
    column = encode(feature, answers_for[feature["id"]], "mean")[0][1]
    return spearman(column[split.dev], split.scores[split.dev])
 
 
def reviews_heatmap(
    plt,
    questions: list[dict],
    answers_for: dict,
    split: Split,
    rows: tuple,
):
    """Compare held-out reviews across the discovered questions, best-signal first.
 
    Rows arrive sorted from the questions that rise with the score to the ones that fall with
    it, so a row above the divider shades left to right and a row below it shades right to
    left.
    """
 
    def value_of(feature: dict, row: int) -> float:
        return float(encode(feature, answers_for[feature["id"]], "mean")[0][1][row])
 
    signs = [polarity(question, answers_for, split) for question in questions]
    flip = next((i for i, s in enumerate(signs) if s < 0), len(questions))
 
    raw = np.array(
        [[value_of(question, row) for row in rows] for question in questions]
    )
    normalized = np.array(
        [
            values / (4 if question["kind"] == "intensity" else 1)
            for question, values in zip(questions, raw)
        ]
    )
    cmap = matplotlib.colors.LinearSegmentedColormap.from_list(
        "typesafe_heat", [SURFACE, "#f7c7ad", ORANGE]
    )
    fig, ax = plt.subplots(
        figsize=(9.5, 1.8 + 0.58 * len(questions)), facecolor=SURFACE
    )
    image = ax.imshow(normalized, aspect="auto", cmap=cmap, vmin=0, vmax=1)
    row_labels = []
    for question, sign in zip(questions, signs):
        kind = "score" if question["kind"] == "intensity" else "noul"
        prefix = f"{sign:+.2f} ({kind}) "
        lines = textwrap.wrap(
            " ".join(question["question"].split()),
            width=52,
            max_lines=2,
            placeholder="...",
            break_long_words=False,
            break_on_hyphens=False,
        )
        row_labels.append(prefix + (f"\n{' ' * len(prefix)}").join(lines))
    column_labels = [
        f"#{i}\n{split.scores[row]:.0f} points\n{' '.join(split.notes[row].split())[:15]}..."
        for i, row in enumerate(rows, 1)
    ]
    ax.set_yticks(np.arange(len(questions)), row_labels)
    ax.set_xticks(np.arange(len(rows)), column_labels)
    ax.tick_params(
        axis="x", top=True, labeltop=True, bottom=False, labelbottom=False, pad=8
    )
    ax.tick_params(axis="y", labelsize=8.5)
    for side in ax.spines.values():
        side.set_visible(False)
    ax.set_xticks(np.arange(-0.5, len(rows), 1), minor=True)
    ax.set_yticks(np.arange(-0.5, len(questions), 1), minor=True)
    ax.grid(which="minor", color=SURFACE, linewidth=2)
    ax.tick_params(which="minor", bottom=False, left=False)
    for i, question in enumerate(questions):
        for j, value in enumerate(raw[i]):
            label = (
                f"{value:.1f}" if question["kind"] == "intensity" else f"{value:.2f}"
            )
            color = SURFACE if normalized[i, j] > 0.58 else INK2
            ax.text(j, i, label, ha="center", va="center", color=color, fontsize=8)
    # the line where the questions stop rising with the score and start falling with it
    if 0 < flip < len(questions):
        ax.axhline(flip - 0.5, color=INK, linewidth=1.2)
        ax.annotate(
            "a higher answer means a worse review, below this line",
            (len(rows) - 0.5, flip - 0.5),
            xytext=(-4, 5),
            textcoords="offset points",
            va="bottom",
            ha="right",
            color=INK2,
            fontsize=8.5,
        )
    colorbar = fig.colorbar(image, ax=ax, fraction=0.025, pad=0.025)
    colorbar.set_ticks([0, 0.5, 1])
    colorbar.set_label("normalized answer", color=INK2, fontsize=8.5)
    colorbar.ax.tick_params(labelsize=8, colors=INK2)
    fig.suptitle(
        "Every question, on five held-out reviews from worst to best",
        x=0.01,
        y=0.995,
        ha="left",
        color=INK,
        fontsize=11,
    )
    fig.text(
        0.01,
        0.972,
        "sorted by how the answer moves with the score, so each row above the line shades "
        "left to right and each row below it shades the other way",
        color=MUTED,
        fontsize=9,
    )
    fig.text(
        0.01,
        0.005,
        "Row labels lead with the rank correlation between that question's answer and the "
        "critic score. Cell text is each question's native scale: score 0-4, noul 0-1.",
        color=MUTED,
        fontsize=8.5,
    )
    return fig
 
 
def rounds_chart(
    plt, curve: list[tuple], history: list[float], n_test: int, gain: tuple
):
    """Dev error and held-out error per round. The trend is the point, not the gap."""
    rounds = list(range(1, len(curve) + 1))
    values = [v for _, v in curve]
 
    fig, ax = plt.subplots(figsize=(7, 3.9), facecolor=SURFACE)
    style(ax)
    ax.grid(axis="y", color=GRID, linewidth=0.8)
    # each dev fold trains on four fifths of the rows, so the dev line sits the higher of the two
    ax.fill_between(rounds, history, values, color=GRID, alpha=0.75, linewidth=0)
    ax.plot(
        rounds,
        history,
        marker="o",
        color=BLUE,
        linewidth=2,
        linestyle="--",
        label="dev, cross-validated - what the loop optimises",
    )
    ax.plot(
        rounds,
        values,
        marker="o",
        color=ORANGE,
        linewidth=2,
        label="held out - what that actually buys",
    )
    # label each point on the outside of the pair, so neither line crowds its own numbers
    for x, dev_value, test_value in zip(rounds, history, values):
        for value, other in ((dev_value, test_value), (test_value, dev_value)):
            ax.annotate(
                f"{value:.2f}",
                (x, value),
                textcoords="offset points",
                xytext=(0, 8 if value >= other else -16),
                ha="center",
                color=INK2,
                fontsize=8.5,
            )
    ax.set_xticks(
        rounds, [f"round {x}\n{n} features" for x, (n, _) in zip(rounds, curve)]
    )
    ax.set_ylabel("RMSE in points (lower is better)", color=INK2, fontsize=9)
    # tight around the two lines: the whole finding lives inside 0.15 of a point
    low, high = min(values + history), max(values + history)
    ax.set_ylim(low - 0.10, high + 0.05)
    difference, low_ci, high_ci = gain
    ax.set_title(
        f"{len(rounds)} rounds of the loop, scored on {n_test} held-out reviews",
        loc="left",
        color=INK,
        fontsize=11,
        pad=20,
    )
    # the number the chart is really about: is the held-out move bigger than the noise?
    ax.text(
        0,
        1.015,
        f"round 1 to round {len(rounds)}, held out: {difference:+.3f} points, "
        f"95% CI [{low_ci:+.3f}, {high_ci:+.3f}]",
        transform=ax.transAxes,
        color=MUTED,
        fontsize=9,
    )
    ax.legend(frameon=False, labelcolor=INK2, fontsize=9, loc="lower left")
    return fig
 

round 1: 18 add, 0 revise, 0 drop
  added  complexity, fruit_intensity, tannin_structure, acidity_intensity,
          oak_intensity, finish_length, balance_harmony, aging_potential,
          positive_superlative_language, negative_critical_language,
          drinkability_easiness, body_richness, sweetness_level, texture_descriptors,
          earthy_savory_notes, flaw_or_defect_mentioned,
          single_vineyard_or_prestige_signal, varietal_blend_detail
  -> 18 features, dev CV RMSE 1.903
 
round 2: 5 add, 3 revise, 3 drop
  added  power_concentration_language, flavor_distinctiveness, generic_fruit_language,
          candied_artificial_flavor, rustic_authentic_character
  reject oak_dominance                     was oak_intensity, would cost +0.005
  revise negative_critical_language        was negative_critical_language, CV 1.897 -> 1.894
  revise single_vineyard_or_prestige_signalwas single_vineyard_or_prestige_signal, CV 1.894 -> 1.881
  keep   finish_length                     would cost +0.009
  keep   texture_descriptors               would cost +0.001
  keep   varietal_blend_detail             would cost +0.023
  -> 23 features, dev CV RMSE 1.881
 
round 3: 7 add, 2 revise, 1 drop
  added  elegance_finesse_language, minerality_precision_language,
          hedged_qualified_praise, underripe_green_character,
          reviewer_overall_verdict_strength, unusual_or_funky_descriptor_valence,
          botrytis_or_special_winemaking_signal
  revise negative_critical_language        was negative_critical_language, CV 1.868 -> 1.864
  revise finish_quality                    was finish_length, CV 1.864 -> 1.861
  keep   candied_artificial_flavor         would cost +0.014
  -> 30 features, dev CV RMSE 1.861
 
round 4: 5 add, 2 revise, 3 drop
  added  excess_or_imbalance_signal, descriptive_detail_density,
          critic_enthusiasm_confidence, savory_food_wine_seriousness,
          note_overall_tone_positivity
  revise rustic_authentic_character        was rustic_authentic_character, CV 1.843 -> 1.838
  reject hedged_qualified_praise           was hedged_qualified_praise, would cost +0.014
  keep   botrytis_or_special_winemaking_signalwould cost +0.011
  keep   candied_artificial_flavor         would cost +0.009
  keep   unusual_or_funky_descriptor_valencewould cost +0.010
  -> 35 features, dev CV RMSE 1.838
 
round 5: 4 add, 2 revise, 8 drop
  added  structural_seriousness, youthful_tension_signal, surface_prettiness_vs_depth,
          price_value_signal
  reject unconventional_character_as_virtuewas rustic_authentic_character, would cost +0.010
  revise flavor_distinctiveness            was flavor_distinctiveness, CV 1.849 -> 1.843
  keep   candied_artificial_flavor         would cost +0.002
  keep   botrytis_or_special_winemaking_signalwould cost +0.003
  keep   hedged_qualified_praise           would cost +0.006
  keep   excess_or_imbalance_signal        would cost +0.005
  drop   underripe_green_character         CV 1.843 -> 1.840
  keep   unusual_or_funky_descriptor_valencewould cost +0.002
  keep   texture_descriptors               would cost +0.001
  keep   generic_fruit_language            would cost +0.000
  -> 38 features, dev CV RMSE 1.840