code/content_rich_ablation.py

"""Richer feature.pkl content features for the post95 + BPR-MF stacker."""

from __future__ import annotations

import argparse
import importlib.util
import pickle as pkl
from pathlib import Path

import lightgbm as lgb
import numpy as np
import pandas as pd
from sklearn.metrics import precision_recall_curve, roc_auc_score
from sklearn.model_selection import StratifiedKFold


def load_module(name: str, path: Path):
    spec = importlib.util.spec_from_file_location(name, path)
    module = importlib.util.module_from_spec(spec)
    assert spec.loader is not None
    spec.loader.exec_module(module)
    return module


def best_f1(y: np.ndarray, s: np.ndarray):
    p, r, t = precision_recall_curve(y, s)
    f = 2 * p * r / (p + r + 1e-12)
    i = int(np.argmax(f))
    th = float(t[i]) if i < len(t) else 0.5
    return float(f[i]), th, float(roc_auc_score(y, s)), float(p[i]), float(r[i])


def fit_lgb_oof(X: np.ndarray, y: np.ndarray, seed: int, n_splits: int, *, ranker_like: bool = False) -> np.ndarray:
    oof = np.zeros(len(y), dtype=np.float32)
    skf = StratifiedKFold(n_splits=n_splits, shuffle=True, random_state=seed)
    for fold, (tr, va) in enumerate(skf.split(X, y), start=1):
        clf = lgb.LGBMClassifier(
            n_estimators=1200 if not ranker_like else 800,
            learning_rate=0.025 if not ranker_like else 0.03,
            num_leaves=31,
            subsample=0.9,
            colsample_bytree=0.9,
            reg_lambda=5.0,
            min_child_samples=80,
            objective="binary",
            verbose=-1,
            random_state=seed + fold,
        )
        clf.fit(X[tr], y[tr])
        oof[va] = clf.predict_proba(X[va])[:, 1]
    return oof


def content_rich_features(root: Path, pairs: np.ndarray, builder) -> np.ndarray:
    cache = root / "validation_runs" / "feature_cache"
    cache.mkdir(parents=True, exist_ok=True)
    path = cache / f"content_rich_{len(pairs)}_{int(pairs[:,0].sum())}_{int(pairs[:,1].sum())}.npy"
    if path.exists():
        return np.load(path)

    with (root / "data_and_docs" / "feature.pkl").open("rb") as f:
        feat = pkl.load(f).numpy().astype(np.float32)
    feat /= np.linalg.norm(feat, axis=1, keepdims=True) + 1e-8

    n_authors = builder.num_authors
    dim = feat.shape[1]
    mean = np.zeros((n_authors, dim), dtype=np.float32)
    mean_normed = np.zeros((n_authors, dim), dtype=np.float32)
    std_scalar = np.zeros(n_authors, dtype=np.float32)
    mean_pair_cos = np.zeros(n_authors, dtype=np.float32)
    hist_count = np.zeros(n_authors, dtype=np.float32)
    for a in range(n_authors):
        hist = np.asarray(list(builder.author_papers[a]), dtype=np.int64)
        hist_count[a] = len(hist)
        if len(hist) == 0:
            continue
        H = feat[hist]
        m = H.mean(axis=0)
        mean[a] = m
        mean_normed[a] = m / (np.linalg.norm(m) + 1e-8)
        dist = np.sum((H - m) ** 2, axis=1)
        std_scalar[a] = float(np.sqrt(dist.mean()))
        if len(hist) > 1:
            sims = H @ H.T
            mean_pair_cos[a] = float((sims.sum() - len(hist)) / (len(hist) * (len(hist) - 1)))
        else:
            mean_pair_cos[a] = 1.0

    out = np.zeros((len(pairs), 18), dtype=np.float32)
    order = np.argsort(pairs[:, 0], kind="mergesort")
    authors = pairs[order, 0]
    boundaries = np.r_[0, np.flatnonzero(authors[1:] != authors[:-1]) + 1, len(order)]
    for lo, hi in zip(boundaries[:-1], boundaries[1:]):
        idx = order[lo:hi]
        a = int(pairs[idx[0], 0])
        cand = pairs[idx, 1].astype(np.int64)
        C = feat[cand]
        center_cos = C @ mean_normed[a]
        center_l2 = np.sqrt(np.sum((C - mean[a]) ** 2, axis=1))
        out[idx, 0] = center_cos
        out[idx, 1] = center_l2
        out[idx, 2] = hist_count[a]
        out[idx, 3] = np.log1p(hist_count[a])
        out[idx, 4] = std_scalar[a]
        out[idx, 5] = mean_pair_cos[a]
        out[idx, 6] = center_cos / (std_scalar[a] + 1e-3)
        hist = np.asarray(list(builder.author_papers[a]), dtype=np.int64)
        if len(hist) == 0:
            continue
        sims = C @ feat[hist].T
        out[idx, 7] = sims.max(axis=1)
        out[idx, 8] = sims.mean(axis=1)
        out[idx, 9] = sims.std(axis=1)
        out[idx, 10] = np.median(sims, axis=1)
        for col, k in [(11, 3), (12, 5), (13, 10)]:
            kk = min(k, sims.shape[1])
            out[idx, col] = np.partition(sims, -kk, axis=1)[:, -kk:].mean(axis=1)
        out[idx, 14] = (sims > 0.5).mean(axis=1)
        out[idx, 15] = (sims > 0.7).mean(axis=1)
        # Percentile of candidate center similarity among this author's test/val candidates.
        vals = center_cos
        local_order = np.argsort(vals, kind="mergesort")
        pct = np.linspace(0, 1, len(vals), dtype=np.float32) if len(vals) > 1 else np.array([1.0], dtype=np.float32)
        tmp = np.zeros(len(vals), dtype=np.float32)
        tmp[local_order] = pct
        out[idx, 16] = tmp
        out[idx, 17] = 1.0 - tmp
    np.save(path, out)
    return out


def main() -> None:
    parser = argparse.ArgumentParser()
    parser.add_argument("--package-root", type=Path, default=Path(__file__).resolve().parents[1])
    parser.add_argument("--split-seed", type=int, default=202)
    parser.add_argument("--main-val-score-file", type=Path, required=True)
    parser.add_argument("--seed", type=int, default=202)
    parser.add_argument("--n-splits", type=int, default=5)
    args = parser.parse_args()

    root = args.package_root
    stack = load_module("stack", root / "code" / "stack_rank_calibration.py")
    lgcn = load_module("lgcn", root / "code" / "train_val_lgcn_ensemble.py")
    post = load_module("post", root / "code" / "post95_ablation.py")
    gen = load_module("gen", root / "code" / "generate_post95_submission.py")
    extra = load_module("extra", root / "code" / "extra_score_sources_ablation.py")

    train_refs, val_pairs = lgcn.make_notebook_style_split(root, args.split_seed, 0.9)
    pairs = val_pairs[["source", "target"]].to_numpy(np.int64)
    y = val_pairs["label"].to_numpy(np.int8)
    main = np.load(args.main_val_score_file).astype(np.float32)
    out_dir = root / "validation_runs" / f"dynamic_seed{args.split_seed}" / "content_rich"
    out_dir.mkdir(parents=True, exist_ok=True)

    builder = stack.ExplicitGraphFeatures(root, train_refs)
    X_hand = builder.transform(pairs)
    X_base = np.column_stack(
        [
            stack.add_rank_features(pairs, main),
            X_hand,
            post.negative_evidence_features(X_hand, main),
            gen.topk_content_similarity_fast(root, pairs, builder),
        ]
    ).astype(np.float32)
    selected = [Path(x.strip()) for x in (root / "validation_runs" / f"dynamic_seed{args.split_seed}" / "post95_submission" / "selected_variant_val_scores.txt").read_text().splitlines() if x.strip()]
    X_base = np.column_stack([X_base, gen.variant_feature_matrix(post, [np.load(p).astype(np.float32) for p in selected])]).astype(np.float32)
    content = extra.content_mean_score(root, pairs, builder)
    mf = np.load(root / "validation_runs" / f"dynamic_seed{args.split_seed}" / "extra_score_sources" / f"val_mf_bpr_s{args.seed}_d256.npy").astype(np.float32)
    Xc, _ = extra.score_to_features(content, "content_mean_cos", pairs)
    Xm, _ = extra.score_to_features(mf, "mf_bpr", pairs)
    X_cm = np.column_stack([X_base, Xc, Xm]).astype(np.float32)

    rows = []
    print("baseline content+mf stack")
    oof = fit_lgb_oof(X_cm, y, args.seed, args.n_splits)
    f1, th, auc, p, r = best_f1(y, oof)
    rows.append({"stage": "content_mf_baseline", "f1": f1, "threshold": th, "auc": auc, "precision": p, "recall": r, "n_features": X_cm.shape[1]})
    np.save(out_dir / "content_mf_baseline_oof.npy", oof)

    print("rich content feature-only model")
    X_rich = content_rich_features(root, pairs, builder)
    rich_oof = fit_lgb_oof(X_rich, y, args.seed + 7, args.n_splits, ranker_like=True)
    f1, th, auc, p, r = best_f1(y, rich_oof)
    rows.append({"stage": "rich_content_only_lgb", "f1": f1, "threshold": th, "auc": auc, "precision": p, "recall": r, "n_features": X_rich.shape[1]})
    np.save(out_dir / "rich_content_only_oof.npy", rich_oof)

    print("stack + rich content raw features")
    X_all = np.column_stack([X_cm, X_rich]).astype(np.float32)
    oof = fit_lgb_oof(X_all, y, args.seed + 11, args.n_splits)
    f1, th, auc, p, r = best_f1(y, oof)
    rows.append({"stage": "+rich_content_features", "f1": f1, "threshold": th, "auc": auc, "precision": p, "recall": r, "n_features": X_all.shape[1]})
    np.save(out_dir / "rich_content_stack_oof.npy", oof)

    print("stack + rich content model score")
    X_score, _ = extra.score_to_features(rich_oof, "rich_content_lgb_oof", pairs)
    X_all_score = np.column_stack([X_all, X_score]).astype(np.float32)
    oof = fit_lgb_oof(X_all_score, y, args.seed + 13, args.n_splits)
    f1, th, auc, p, r = best_f1(y, oof)
    rows.append({"stage": "+rich_content_model_score", "f1": f1, "threshold": th, "auc": auc, "precision": p, "recall": r, "n_features": X_all_score.shape[1]})
    np.save(out_dir / "rich_content_model_score_stack_oof.npy", oof)

    result = pd.DataFrame(rows).sort_values("f1", ascending=False)
    result.to_csv(out_dir / "content_rich_ablation.csv", index=False)
    print(result.to_string(index=False))


if __name__ == "__main__":
    main()