"""Advanced feature engineering pipeline with synthetic features."""

from __future__ import annotations

import argparse
import json
import sys
import time
from pathlib import Path
from typing import Dict, List, Tuple

import numpy as np
import pandas as pd
from catboost import CatBoostClassifier
from lightgbm import LGBMClassifier
from sklearn.metrics import (
    accuracy_score,
    average_precision_score,
    confusion_matrix,
    f1_score,
    precision_score,
    recall_score,
    roc_auc_score,
)
from sklearn.preprocessing import StandardScaler
from xgboost import XGBClassifier

try:
    from imblearn.over_sampling import SMOTE
    SMOTE_AVAILABLE = True
except ImportError:
    SMOTE_AVAILABLE = False

ROOT = Path(__file__).resolve().parents[2]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

EPS = 1e-9


def _agg_numeric(frame: pd.DataFrame, key: str, value_cols, prefix: str) -> pd.DataFrame:
    """Aggregate numeric features."""
    grouped = frame.groupby(key, sort=False)[list(value_cols)]
    agg = grouped.agg(["mean", "std", "min", "max", "median"])
    agg.columns = [f"{prefix}_{col}_{stat}" for col, stat in agg.columns]
    agg = agg.reset_index()
    for col in agg.columns:
        if col != key:
            agg[col] = agg[col].fillna(0.0)
    return agg


def _build_features_with_engineering(benchmark_dir: Path) -> pd.DataFrame:
    """Build features with advanced synthetic feature engineering."""
    marker_path = benchmark_dir / "marker_table.csv"
    sample_key = "sample_file"

    marker_cols = [
        sample_key,
        "marker",
        "dye",
        "peak_count_total",
        "peak_count_non_ol",
        "max_height",
        "sum_height",
        "has_ol",
    ]
    marker = pd.read_csv(marker_path, usecols=marker_cols, low_memory=False)

    marker["peak_nonol_ratio"] = marker["peak_count_non_ol"] / (marker["peak_count_total"] + EPS)
    marker["height_density"] = marker["sum_height"] / (marker["peak_count_total"] + EPS)
    marker["max_ratio"] = marker["max_height"] / (marker["sum_height"] + EPS)

    # ===== BASE FEATURES =====
    gm = marker.groupby(sample_key, sort=False)
    mfeat = pd.DataFrame(
        {
            sample_key: gm.size().index,
            "marker_rows": gm.size().values,
            "marker_unique_count": gm["marker"].nunique().values,
            "marker_has_ol_rate": gm["has_ol"].mean().values,
            "marker_peak_total_sum": gm["peak_count_total"].sum().values,
            "marker_peak_nonol_sum": gm["peak_count_non_ol"].sum().values,
            "marker_peak_nonol_ratio_mean": gm["peak_nonol_ratio"].mean().values,
            "marker_height_density_mean": gm["height_density"].mean().values,
        }
    )

    mnum = _agg_numeric(
        marker,
        key=sample_key,
        value_cols=[
            "peak_count_total",
            "peak_count_non_ol",
            "peak_nonol_ratio",
            "max_height",
            "sum_height",
            "height_density",
            "max_ratio",
        ],
        prefix="marker",
    )
    mfeat = mfeat.merge(mnum, on=sample_key, how="left")

    # ===== DYE FEATURES =====
    dye_sum = marker.pivot_table(
        index=sample_key,
        columns="dye",
        values="sum_height",
        aggfunc="sum",
        fill_value=0.0,
    )
    dye_sum.columns = [f"marker_sum_height_dye_{c}" for c in dye_sum.columns]
    mfeat = mfeat.merge(dye_sum.reset_index(), on=sample_key, how="left")

    # ===== ADVANCED SYNTHETIC FEATURES =====
    print("  ✨ Engineering synthetic features...")

    # 1. Marker quality features
    mfeat["marker_avg_peak_count"] = mfeat["marker_peak_total_sum"] / (mfeat["marker_unique_count"] + EPS)
    mfeat["marker_nonol_ratio"] = mfeat["marker_peak_nonol_sum"] / (mfeat["marker_peak_total_sum"] + EPS)

    # 2. Height-based features (from aggregated marker features)
    if "marker_sum_height_std" in mfeat.columns:
        mfeat["marker_height_coefficient_of_variation"] = (
            mfeat["marker_sum_height_std"] / (mfeat["marker_sum_height_mean"] + EPS)
        )
    if "marker_sum_height_max" in mfeat.columns and "marker_sum_height_min" in mfeat.columns:
        mfeat["marker_height_range"] = mfeat["marker_sum_height_max"] - mfeat["marker_sum_height_min"]

    # 3. Variance features
    if "marker_peak_count_total_std" in mfeat.columns:
        mfeat["marker_peak_variance"] = mfeat["marker_peak_count_total_std"]

    # 4. Dye balance features
    dye_cols = [c for c in mfeat.columns if c.startswith("marker_sum_height_dye_")]
    if dye_cols and len(dye_cols) > 1:
        dye_values = mfeat[dye_cols].fillna(0).values
        mfeat["dye_count"] = (dye_values > 0).sum(axis=1)
        dye_sums = dye_values.sum(axis=1, keepdims=True) + EPS
        dye_norm = dye_values / dye_sums
        mfeat["dye_balance_entropy"] = -np.sum(dye_norm * np.log(dye_norm + EPS), axis=1)
        mfeat["dye_dominant_ratio"] = dye_values.max(axis=1) / (dye_values.sum(axis=1) + EPS)
        mfeat["dye_magnitude_range"] = dye_values.max(axis=1) - dye_values.min(axis=1)

    # 5. Outlier features
    mfeat["marker_ol_severity"] = mfeat["marker_has_ol_rate"] * mfeat["marker_rows"]
    mfeat["marker_nonol_density"] = (
        mfeat["marker_peak_nonol_sum"] / (mfeat["marker_rows"] + EPS)
    )

    # 6. Distribution features (if available)
    if "marker_sum_height_max" in mfeat.columns and "marker_sum_height_min" in mfeat.columns:
        mfeat["marker_min_max_ratio"] = (
            mfeat["marker_sum_height_min"] / (mfeat["marker_sum_height_max"] + EPS)
        )
    if "marker_sum_height_median" in mfeat.columns and "marker_sum_height_mean" in mfeat.columns:
        mfeat["marker_median_mean_ratio"] = (
            mfeat["marker_sum_height_median"] / (mfeat["marker_sum_height_mean"] + EPS)
        )

    # 7. Interaction features
    mfeat["marker_complexity"] = (
        mfeat["marker_unique_count"] * mfeat["marker_rows"] * mfeat["marker_has_ol_rate"]
    )
    mfeat["marker_quality_score"] = (
        mfeat["marker_nonol_ratio"] * (1 - mfeat["marker_has_ol_rate"]) * mfeat["marker_peak_nonol_ratio_mean"]
    )

    # 8. Robustness features
    if "marker_peak_count_total_std" in mfeat.columns and "marker_peak_count_total_mean" in mfeat.columns:
        mfeat["marker_consistency"] = (
            1 - (mfeat["marker_peak_count_total_std"] / (mfeat["marker_peak_count_total_mean"] + EPS))
        ).clip(0, 1)

    # Fill NaN values
    mfeat = mfeat.fillna(0)
    mfeat = mfeat.replace([np.inf, -np.inf], 0)

    return mfeat


def _tune_threshold(y_true: np.ndarray, prob: np.ndarray, steps: int) -> Tuple[float, float]:
    """Tune threshold for F1 score."""
    thresholds = np.linspace(0.01, 0.99, steps)
    best_f1 = -1.0
    best_th = 0.5
    for th in thresholds:
        pred = (prob >= th).astype(int)
        score = f1_score(y_true, pred, zero_division=0)
        if score > best_f1:
            best_f1 = float(score)
            best_th = float(th)
    return best_th, best_f1


def _metrics(y_true: np.ndarray, prob: np.ndarray, threshold: float) -> Dict[str, float]:
    pred = (prob >= threshold).astype(int)
    tn, fp, fn, tp = confusion_matrix(y_true, pred, labels=[0, 1]).ravel()
    specificity = tn / (tn + fp + EPS)
    precision = precision_score(y_true, pred, zero_division=0)
    recall = recall_score(y_true, pred, zero_division=0)
    f2 = (5 * precision * recall) / (4 * precision + recall + EPS)
    return {
        "roc_auc": float(roc_auc_score(y_true, prob)),
        "pr_auc": float(average_precision_score(y_true, prob)),
        "f1": float(f1_score(y_true, pred, zero_division=0)),
        "f2": float(f2),
        "precision": float(precision),
        "recall": float(recall),
        "specificity": float(specificity),
        "accuracy": float(accuracy_score(y_true, pred)),
        "tp": int(tp),
        "fp": int(fp),
        "tn": int(tn),
        "fn": int(fn),
    }


def run(args: argparse.Namespace) -> Tuple[pd.DataFrame, pd.DataFrame]:
    args.out_dir.mkdir(parents=True, exist_ok=True)

    print("=" * 80)
    print("🚀 ADVANCED FEATURE ENGINEERING PIPELINE")
    print("=" * 80)

    per_split_rows: List[Dict[str, object]] = []
    trial_rows: List[Dict[str, object]] = []

    total_start = time.time()

    for benchmark_name in args.benchmarks:
        print(f"\n📊 Processing benchmark: {benchmark_name}")
        benchmark_dir = args.benchmark_root / benchmark_name
        labels = pd.read_csv(benchmark_dir / "sample_labels_all_splits.csv", low_memory=False)
        features = _build_features_with_engineering(benchmark_dir)

        for split_idx, split_id in enumerate(sorted(labels["split_id"].unique())):
            print(f"  Split {split_idx + 1}/{len(labels['split_id'].unique())}: {split_id}", end=" ")
            split_start = time.time()

            split_df = labels[labels["split_id"] == split_id].copy()
            data = split_df.merge(features, on="sample_file", how="inner")

            drop_cols = {
                "benchmark_id",
                "split_id",
                "partition",
                "study_id",
                "panel",
                "sample_file",
                "sample_family_id",
                "true_contributors",
                "known_contributors_true",
                "unknown_contributors_true",
                "num_known_in_sample",
                "num_unknown_in_sample",
                "unknown_present",
                "total_contributors",
            }
            feature_cols = [c for c in data.columns if c not in drop_cols]
            x_all = data[feature_cols].astype(float).values

            y_all = data["unknown_present"].astype(int).values
            partition = data["partition"].values
            train_idx = partition == "train"
            dev_idx = partition == "dev"
            test_idx = partition == "test"

            x_train = x_all[train_idx]
            y_train = y_all[train_idx]
            x_dev = x_all[dev_idx]
            y_dev = y_all[dev_idx]
            x_test = x_all[test_idx]
            y_test = y_all[test_idx]

            # SMOTE
            if SMOTE_AVAILABLE:
                smote = SMOTE(random_state=42, k_neighbors=5)
                x_train, y_train = smote.fit_resample(x_train, y_train)

            # Feature scaling
            scaler = StandardScaler()
            x_train = scaler.fit_transform(x_train)
            x_dev = scaler.transform(x_dev)
            x_test = scaler.transform(x_test)

            # Training
            pos = float((y_train == 1).sum())
            neg = float((y_train == 0).sum())
            spw = max(1.0, neg / max(pos, 1.0))

            lgbm = LGBMClassifier(
                n_estimators=1500,
                learning_rate=0.01,
                num_leaves=80,
                subsample=0.80,
                colsample_bytree=0.80,
                min_child_samples=25,
                lambda_l1=2.0,
                lambda_l2=2.0,
                class_weight="balanced",
                random_state=42,
                verbose=-1,
                n_jobs=-1,
            )

            xgb = XGBClassifier(
                n_estimators=1500,
                learning_rate=0.01,
                max_depth=6,
                min_child_weight=7,
                subsample=0.80,
                colsample_bytree=0.80,
                reg_alpha=2.0,
                reg_lambda=2.0,
                scale_pos_weight=spw,
                eval_metric="logloss",
                random_state=42,
                n_jobs=-1,
            )

            lgbm.fit(x_train, y_train)
            xgb.fit(x_train, y_train)

            p_dev_l = lgbm.predict_proba(x_dev)[:, 1]
            p_dev_x = xgb.predict_proba(x_dev)[:, 1]
            p_test_l = lgbm.predict_proba(x_test)[:, 1]
            p_test_x = xgb.predict_proba(x_test)[:, 1]

            # Threshold tuning (F1)
            th_l, dev_f1_l = _tune_threshold(y_dev, p_dev_l, args.threshold_steps)
            th_x, dev_f1_x = _tune_threshold(y_dev, p_dev_x, args.threshold_steps)

            # 2-Model ensemble
            best_weight = 0.5
            best_th = 0.5
            best_f1 = -1.0
            for w in np.linspace(0.0, 1.0, 21):
                p_dev = (w * p_dev_l) + ((1.0 - w) * p_dev_x)
                th, dev_f1 = _tune_threshold(y_dev, p_dev, args.threshold_steps)
                if dev_f1 > best_f1:
                    best_f1 = dev_f1
                    best_th = th
                    best_weight = float(w)

            p_test = (best_weight * p_test_l) + ((1.0 - best_weight) * p_test_x)

            model_payload = {
                "lightgbm": {
                    "threshold": th_l,
                    "dev_f1": dev_f1_l,
                    "test_prob": p_test_l,
                },
                "xgboost": {
                    "threshold": th_x,
                    "dev_f1": dev_f1_x,
                    "test_prob": p_test_x,
                },
                "fusion": {
                    "threshold": best_th,
                    "dev_f1": best_f1,
                    "test_prob": p_test,
                    "weight": best_weight,
                },
            }

            for model_name, payload in model_payload.items():
                m = _metrics(y_test, payload["test_prob"], float(payload["threshold"]))
                per_split_rows.append(
                    {
                        "benchmark": benchmark_name,
                        "split_id": split_id,
                        "model": model_name,
                        **m,
                    }
                )

            split_elapsed = time.time() - split_start
            print(f"✅ {split_elapsed:.1f}s")

    per_split = pd.DataFrame(per_split_rows).sort_values(["benchmark", "model", "split_id"])

    summary = (
        per_split.groupby(["benchmark", "model"], as_index=False)
        .agg(
            f1_mean=("f1", "mean"),
            f1_std=("f1", "std"),
            precision_mean=("precision", "mean"),
            recall_mean=("recall", "mean"),
            roc_auc_mean=("roc_auc", "mean"),
        )
        .sort_values(["benchmark", "model"])
    )

    per_split.to_csv(args.out_dir / "advanced_features_per_split.csv", index=False)
    summary.to_csv(args.out_dir / "advanced_features_summary.csv", index=False)

    total_elapsed = time.time() - total_start
    print(f"\n{'=' * 80}")
    print(f"✅ Total time: {total_elapsed / 60:.1f} minutes")
    print(f"Features: {len(feature_cols)} total")
    print(f"{'=' * 80}\n")

    return per_split, summary


def main() -> None:
    parser = argparse.ArgumentParser()
    parser.add_argument("--benchmark-root", type=Path, default=Path("data/processed"))
    parser.add_argument("--benchmarks", nargs="+", default=["rd14-fullref-50_multisplit_v2", "rd12-fullref-61_multisplit_v2"])
    parser.add_argument("--out-dir", type=Path, default=Path("outputs/benchmarks/advanced_features"))
    parser.add_argument("--threshold-steps", type=int, default=199)
    args = parser.parse_args()

    _, summary = run(args)
    print("\n📊 RESULTS:")
    print(summary.to_string(index=False))


if __name__ == "__main__":
    main()