#!/usr/bin/env python3
"""
GT-comparison event detection analysis.

Primary metric : AUC-ROC  (threshold-free model comparison)
Operating point: Youden's J  =  argmax(TPR + TNR − 1)
                 Found on pooled scores from both models → single shared threshold.

Binary labels:  PRESENT = 1  (keep command, distractor in GT)
                REMOVED = 0  (remove command, distractor absent from GT)

Only eval_outputs_test_3k (non-OOD) is used.

Usage:
    python analyze_detection_scores_gt.py
    python analyze_detection_scores_gt.py --sisnr_threshold 2.5 --nxcorr_threshold 0.80 --clap_threshold 0.65
"""

import argparse
from pathlib import Path

import numpy as np
import pandas as pd
from sklearn.metrics import roc_auc_score, roc_curve

# ── Paths ─────────────────────────────────────────────────────────────────────
BASE_DIR = Path(__file__).parent

MODELS_FINAL = {
    "combined_v1":          BASE_DIR / "experiments_final/combined_v1",
    "no_TSDL_old_mixtures": BASE_DIR / "experiments_final/no_TSDL_old_mixtures",
}

TEST_3K_CSV = "eval_outputs_test_3k/event_detection_scores_gt.csv"


# ═══════════════════════════════════════════════════════════════════════════════

def load_csv(path: Path) -> pd.DataFrame:
    df = pd.read_csv(path)
    df = df[df["error"].isna() | (df["error"] == "")]
    for col in ["si_snr_db", "nxcorr", "clap_sim"]:
        df[col] = pd.to_numeric(df[col], errors="coerce")
    df["gt_binary"] = df["gt_label"].map({"PRESENT": 1, "REMOVED": 0})
    return df


def print_section(title: str):
    print(f"\n{'═'*70}")
    print(f"  {title}")
    print(f"{'═'*70}")


def predict(series: pd.Series, threshold: float) -> pd.Series:
    return (series > threshold).map({True: "PRESENT", False: "REMOVED"})


def accuracy(pred: pd.Series, gt: pd.Series) -> float:
    valid = gt.notna() & pred.notna()
    if valid.sum() == 0:
        return float("nan")
    return (pred[valid] == gt[valid]).mean() * 100.0


# ═══════════════════════════════════════════════════════════════════════════════
# Score statistics
# ═══════════════════════════════════════════════════════════════════════════════

def print_score_stats(dfs: dict):
    print_section("Score statistics  (higher = model output matches GT better)")
    header = f"  {'metric':<12} {'stat':<8}"
    for name in dfs:
        header += f"  {name:>26}"
    print(header)
    print("  " + "─" * (22 + len(dfs) * 28))
    for col in ["si_snr_db", "nxcorr", "clap_sim"]:
        for stat, fn in [("mean", np.nanmean), ("median", np.nanmedian), ("std", np.nanstd)]:
            row = f"  {col:<12} {stat:<8}"
            for df in dfs.values():
                row += f"  {fn(df[col].dropna().values):>26.4f}"
            print(row)
        print()


# ═══════════════════════════════════════════════════════════════════════════════
# AUC + Youden's J
# ═══════════════════════════════════════════════════════════════════════════════

def compute_auc(df: pd.DataFrame, col: str) -> float:
    """AUC-ROC for one model / one metric."""
    valid = df[col].notna() & df["gt_binary"].notna()
    if valid.sum() < 2:
        return float("nan")
    return roc_auc_score(df.loc[valid, "gt_binary"], df.loc[valid, col])


def youden_threshold(scores: np.ndarray, labels: np.ndarray) -> float:
    """
    Find threshold T* = argmax(TPR + TNR − 1) via sklearn's roc_curve.
    scores : continuous scores
    labels : binary  (1 = PRESENT, 0 = REMOVED)
    """
    fpr, tpr, thresholds = roc_curve(labels, scores)
    j = tpr + (1.0 - fpr) - 1.0        # Youden's J at each point
    best = int(np.argmax(j))
    return float(thresholds[best])


def pooled_youden_threshold(dfs: dict, col: str) -> float:
    """
    Youden's J on the combined scores of all models.
    Gives a single shared operating-point threshold for fair comparison.
    """
    all_scores = pd.concat([df[col].dropna() for df in dfs.values()])
    all_labels = pd.concat([
        df.loc[df[col].notna(), "gt_binary"].dropna()
        for df in dfs.values()
    ])
    # align index
    valid = all_scores.notna() & all_labels.notna()
    return youden_threshold(all_scores[valid].values, all_labels[valid].values)


def print_auc_and_youden(dfs: dict) -> dict:
    """
    Print AUC table and per-model Youden thresholds.
    Returns {col: pooled_youden_T} for use in the breakdown tables.
    """
    metrics = [
        ("SI-SNR",   "si_snr_db"),
        ("NXCorr",   "nxcorr"),
        ("CLAP sim", "clap_sim"),
    ]
    model_names = list(dfs.keys())

    # ── AUC table ─────────────────────────────────────────────────────────────
    print_section("AUC-ROC  (threshold-free model comparison; higher = better)")
    print(f"\n  {'Metric':<12} {'N':>6}", end="")
    for name in model_names:
        print(f"  {name:>26}", end="")
    print()
    print("  " + "─" * (20 + len(model_names) * 28))

    for m_label, col in metrics:
        first_df = list(dfs.values())[0]
        n = (first_df[col].notna() & first_df["gt_binary"].notna()).sum()
        print(f"  {m_label:<12} {n:>6}", end="")
        for df in dfs.values():
            auc = compute_auc(df, col)
            print(f"  {auc:>26.4f}", end="")
        print()

    # ── Youden thresholds ─────────────────────────────────────────────────────
    print_section(
        "Youden's J operating-point threshold\n"
        "  T* = argmax(TPR + TNR − 1)  on pooled scores from both models\n"
        "  Per-model T* shown for reference; pooled T* used in breakdown tables"
    )

    youden_thresholds = {}

    for m_label, col in metrics:
        pooled_t = pooled_youden_threshold(dfs, col)
        youden_thresholds[col] = pooled_t

        print(f"\n  {m_label}")
        for name, df in dfs.items():
            valid = df[col].notna() & df["gt_binary"].notna()
            t_model = youden_threshold(
                df.loc[valid, col].values,
                df.loc[valid, "gt_binary"].values,
            )
            # TPR and TNR at model-specific T
            tpr = (df.loc[valid & (df["gt_label"] == "PRESENT"), col] > t_model).mean()
            tnr = (df.loc[valid & (df["gt_label"] == "REMOVED"),  col] <= t_model).mean()
            j   = tpr + tnr - 1.0
            print(f"    {name:<30}  T*={t_model:.4f}  TPR={tpr:.3f}  TNR={tnr:.3f}  J={j:.3f}")

        # Pooled stats
        all_s, all_l = [], []
        for df in dfs.values():
            valid = df[col].notna() & df["gt_binary"].notna()
            all_s.append(df.loc[valid, col].values)
            all_l.append(df.loc[valid, "gt_binary"].values)
        s = np.concatenate(all_s)
        l = np.concatenate(all_l)
        tpr_p = (s[l == 1] > pooled_t).mean()
        tnr_p = (s[l == 0] <= pooled_t).mean()
        j_p   = tpr_p + tnr_p - 1.0
        print(f"    {'[pooled]':<30}  T*={pooled_t:.4f}  TPR={tpr_p:.3f}  TNR={tnr_p:.3f}  J={j_p:.3f}")

    return youden_thresholds


# ═══════════════════════════════════════════════════════════════════════════════
# Breakdown tables at a fixed threshold
# ═══════════════════════════════════════════════════════════════════════════════

def analyse(dfs: dict, sisnr_t: float, nxcorr_t: float, clap_t: float,
            label: str = ""):
    metrics = [
        ("SI-SNR",   "si_snr_db", sisnr_t),
        ("NXCorr",   "nxcorr",    nxcorr_t),
        ("CLAP sim", "clap_sim",  clap_t),
    ]
    model_names = list(dfs.keys())
    suffix = f"  [{label}]" if label else ""

    print_section(
        f"Accuracy vs gt_label at Youden threshold{suffix}\n"
        f"  SI-SNR>{sisnr_t:+.4f}dB | NXCorr>{nxcorr_t:.4f} | CLAP>{clap_t:.4f}"
    )

    # ── Overall ───────────────────────────────────────────────────────────────
    print(f"\n  {'Metric':<12} {'N':>6}", end="")
    for name in model_names:
        print(f"  {name:>26}", end="")
    print()
    print("  " + "─" * (20 + len(model_names) * 28))

    for m_label, col, thr in metrics:
        first_df = list(dfs.values())[0]
        n = (first_df[col].notna() & first_df["gt_label"].notna()).sum()
        print(f"  {m_label:<12} {n:>6}", end="")
        for df in dfs.values():
            valid = df[col].notna() & df["gt_label"].notna()
            pred  = predict(df.loc[valid, col], thr)
            acc   = accuracy(pred, df.loc[valid, "gt_label"])
            print(f"  {'%.2f%%' % acc:>26}", end="")
        print()

    # ── Per-command-type ──────────────────────────────────────────────────────
    print_section(f"Accuracy by command_type{suffix}")
    command_types = sorted(
        set().union(*[set(df["command_type"].dropna()) for df in dfs.values()])
    )

    for m_label, col, thr in metrics:
        print(f"\n  [ {m_label} @ T*={thr:.4f} ]\n")
        print(f"  {'command_type':<22} {'N':>6}", end="")
        for name in model_names:
            print(f"  {name:>26}", end="")
        print()
        print("  " + "─" * (30 + len(model_names) * 28))

        for ct in command_types:
            row_str = f"  {ct:<22}"
            n_shown = False
            for df in dfs.values():
                sub   = df[df["command_type"] == ct]
                valid = sub[col].notna() & sub["gt_label"].notna()
                if not n_shown:
                    row_str += f" {valid.sum():>6}"
                    n_shown = True
                pred = predict(sub.loc[valid, col], thr)
                acc  = accuracy(pred, sub.loc[valid, "gt_label"])
                s    = f"{'%.2f%%' % acc}" if not np.isnan(acc) else "N/A"
                row_str += f"  {s:>26}"
            print(row_str)

    # ── Per-distractor (CLAP) ─────────────────────────────────────────────────
    print_section(f"Accuracy by distractor_name  (CLAP @ T*={clap_t:.4f}){suffix}  sorted by {model_names[0]}")
    col, thr = "clap_sim", clap_t
    dist_names = sorted(list(dfs.values())[0]["distractor_name"].dropna().unique())

    rows = []
    for dname in dist_names:
        row = {"distractor": dname}
        for name, df in dfs.items():
            sub   = df[df["distractor_name"] == dname]
            valid = sub[col].notna() & sub["gt_label"].notna()
            pred  = predict(sub.loc[valid, col], thr)
            row[name]        = accuracy(pred, sub.loc[valid, "gt_label"])
            row[f"{name}_n"] = valid.sum()
        rows.append(row)

    dist_df = pd.DataFrame(rows).sort_values(model_names[0], ascending=False)
    print(f"\n  {'distractor':<32} {'N':>5}", end="")
    for name in model_names:
        print(f"  {name:>26}", end="")
    print()
    print("  " + "─" * (39 + len(model_names) * 28))
    for _, r in dist_df.iterrows():
        n = int(r[f"{model_names[0]}_n"])
        print(f"  {r['distractor']:<32} {n:>5}", end="")
        for name in model_names:
            v = r[name]
            print(f"  {'%.2f%%' % v if not np.isnan(v) else 'N/A':>26}", end="")
        print()

    # ── gt_label split ────────────────────────────────────────────────────────
    print_section(f"Accuracy by gt_label  (CLAP @ T*={clap_t:.4f}){suffix}")
    print(f"  {'gt_label':<12} {'N':>6}", end="")
    for name in model_names:
        print(f"  {name:>26}", end="")
    print()
    print("  " + "─" * (20 + len(model_names) * 28))
    for lbl in ["REMOVED", "PRESENT"]:
        row_str = f"  {lbl:<12}"
        n_shown = False
        for df in dfs.values():
            sub   = df[df["gt_label"] == lbl]
            valid = sub[col].notna() & sub["gt_label"].notna()
            if not n_shown:
                row_str += f" {valid.sum():>6}"
                n_shown = True
            pred = predict(sub.loc[valid, col], thr)
            acc  = accuracy(pred, sub.loc[valid, "gt_label"])
            row_str += f"  {'%.2f%%' % acc if not np.isnan(acc) else 'N/A':>26}"
        print(row_str)


# ═══════════════════════════════════════════════════════════════════════════════

def main():
    parser = argparse.ArgumentParser(
        description="GT event detection analysis: AUC + Youden's J threshold."
    )
    parser.add_argument("--sisnr_threshold",  type=float, default=None,
                        help="Override SI-SNR threshold (default: Youden's J from data)")
    parser.add_argument("--nxcorr_threshold", type=float, default=None,
                        help="Override NXCorr threshold (default: Youden's J from data)")
    parser.add_argument("--clap_threshold",   type=float, default=None,
                        help="Override CLAP threshold (default: Youden's J from data)")
    args = parser.parse_args()

    dfs = {}
    for name, model_path in MODELS_FINAL.items():
        p = model_path / TEST_3K_CSV
        if not p.exists():
            print(f"[WARN] CSV not found: {p}")
            continue
        df = load_csv(p)
        print(f"Loaded {len(df):>5} rows  ({df['gt_label'].notna().sum()} with gt_label)  ← {name}")
        dfs[name] = df

    if not dfs:
        print("No CSVs found. Run the GT eval jobs first.")
        return

    print_score_stats(dfs)
    youden_t = print_auc_and_youden(dfs)

    # Use Youden thresholds unless overridden
    sisnr_t  = args.sisnr_threshold  if args.sisnr_threshold  is not None else youden_t["si_snr_db"]
    nxcorr_t = args.nxcorr_threshold if args.nxcorr_threshold is not None else youden_t["nxcorr"]
    clap_t   = args.clap_threshold   if args.clap_threshold   is not None else youden_t["clap_sim"]

    label = "Youden's J pooled" if args.clap_threshold is None else "manual override"
    analyse(dfs, sisnr_t, nxcorr_t, clap_t, label=label)


if __name__ == "__main__":
    main()