#!/usr/bin/env python3
"""Inspect downloaded PHM-Vibench metadata and H5 samples locally."""

from __future__ import annotations

import argparse
import sys
from pathlib import Path

from phm_vibench_manifest import DATASET_TO_FILE, FILE_SIZES


REQUIRED_COLUMNS = ["Id", "Name", "File", "Label", "Sample_rate", "Sample_lenth", "Channel"]


def import_pandas():
    try:
        import pandas as pd
    except ImportError as exc:
        raise SystemExit("Missing dependency: pandas/openpyxl. Install with `pip install -r requirements.txt`.") from exc
    return pd


def import_h5py():
    try:
        import h5py
    except ImportError as exc:
        raise SystemExit("Missing dependency: h5py. Install with `pip install -r requirements.txt`.") from exc
    return h5py


def load_metadata(root: Path):
    path = root / "metadata.xlsx"
    if not path.is_file():
        raise SystemExit(f"Missing metadata.xlsx under {root}")
    pd = import_pandas()
    df = pd.read_excel(path)
    missing = [column for column in REQUIRED_COLUMNS if column not in df.columns]
    if missing:
        raise SystemExit("metadata.xlsx missing required columns: " + ", ".join(missing))
    return df


def print_dataset_summary(df) -> None:
    counts = df["Name"].value_counts().sort_index()
    print("datasets:", len(counts))
    for dataset, count in counts.items():
        file_name = DATASET_TO_FILE.get(dataset, "")
        print(f"{dataset:<18} samples={count:<6} file={file_name}")


def normalize_dataset_id(dataset: str) -> str:
    lookup = {name.lower(): name for name in DATASET_TO_FILE}
    normalized = lookup.get(dataset.lower())
    if normalized is None:
        raise SystemExit(f"Unknown dataset {dataset}. Use --list-datasets to inspect valid dataset ids.")
    return normalized


def choose_smoke_dataset(root: Path) -> str:
    present = []
    for dataset, h5_name in DATASET_TO_FILE.items():
        if (root / h5_name).is_file():
            present.append((FILE_SIZES[h5_name], dataset))
    if not present:
        raise SystemExit(f"No published H5 file found under {root}; download --preset demo or choose --metadata-only")
    present.sort()
    return present[0][1]


def select_sample(df, dataset: str, sample_index: int, sample_id: str | None):
    rows = df[df["Name"].eq(dataset)].reset_index(drop=True)
    if rows.empty:
        raise SystemExit(f"Dataset {dataset} not found in metadata.xlsx")
    if sample_id is not None:
        matches = rows[rows["Id"].astype(str).eq(sample_id)]
        if matches.empty:
            raise SystemExit(f"Sample id {sample_id} not found in dataset {dataset}")
        return matches.iloc[0], len(rows)
    if sample_index < 0 or sample_index >= len(rows):
        raise SystemExit(f"--sample-index must be in [0, {len(rows) - 1}] for {dataset}")
    return rows.iloc[sample_index], len(rows)


def inspect_sample(root: Path, dataset: str, sample_index: int, sample_id: str | None, *, metadata_only: bool) -> None:
    df = load_metadata(root)
    row, dataset_rows = select_sample(df, dataset, sample_index, sample_id)
    sample_key = str(int(row["Id"]))
    h5_name = DATASET_TO_FILE.get(dataset)
    if h5_name is None:
        raise SystemExit(f"Dataset {dataset} is not in the published H5 manifest")

    print(f"root={root}")
    print(f"dataset={dataset} samples={dataset_rows} h5={h5_name}")
    print(
        "sample "
        f"id={sample_key} label={row['Label']} sample_rate={row['Sample_rate']} "
        f"sample_lenth={row['Sample_lenth']} channel={row['Channel']}"
    )

    if metadata_only:
        return

    h5_path = root / h5_name
    if not h5_path.is_file():
        raise SystemExit(f"Missing {h5_name} under {root}")
    h5py = import_h5py()
    with h5py.File(h5_path, "r") as h5:
        if sample_key not in h5:
            raise SystemExit(f"Sample id {sample_key} not found in {h5_name}")
        dataset_obj = h5[sample_key]
        print(f"h5 key={sample_key} shape={dataset_obj.shape} dtype={dataset_obj.dtype}")


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--root", type=Path, default=Path("PHM-Vibench"), help="Downloaded dataset root")
    parser.add_argument("--dataset", default="RM_007_MFPT", help="Dataset id such as RM_007_MFPT; case-insensitive")
    parser.add_argument("--sample-index", type=int, default=0, help="Zero-based sample index within --dataset")
    parser.add_argument("--sample-id", help="Explicit sample Id from metadata.xlsx; overrides --sample-index")
    parser.add_argument("--metadata-only", action="store_true", help="Inspect metadata without opening the H5 file")
    parser.add_argument("--list-datasets", action="store_true", help="List dataset sample counts from metadata.xlsx")
    parser.add_argument("--smoke", action="store_true", help="Inspect the smallest published H5 file present under --root")
    return parser.parse_args()


def main() -> int:
    args = parse_args()
    if args.list_datasets:
        print_dataset_summary(load_metadata(args.root))
        return 0
    dataset = choose_smoke_dataset(args.root) if args.smoke else normalize_dataset_id(args.dataset)
    inspect_sample(
        args.root,
        dataset,
        args.sample_index,
        args.sample_id,
        metadata_only=args.metadata_only,
    )
    return 0


if __name__ == "__main__":
    sys.exit(main())