# scripts/make_mini_subset.py
# Create a tiny subset under data-mini/ for quick demos/Spaces.
import os, shutil
from pathlib import Path
import pandas as pd

ROOT = Path(__file__).resolve().parents[1]
SRC_META = ROOT / "data" / "metadata" / "metadata.csv"
SRC_DATA = ROOT / "data"
DST = ROOT / "data-mini"

N_TRAIN = 200
N_VALID = 50

def main():
    if not SRC_META.exists():
        raise SystemExit(f"Missing: {SRC_META}")
    df = pd.read_csv(SRC_META)
    if "wav" not in df.columns or "split" not in df.columns:
        raise SystemExit("metadata.csv must have 'wav' and 'split' columns")

    train = df[df["split"].str.lower()=="train"].sample(min(N_TRAIN, sum(df["split"].str.lower()=="train")), random_state=0)
    valid = df[df["split"].str.lower()=="valid"]
    if len(valid)==0:
        valid = df[df["split"].str.lower()=="train"].drop(train.index).sample(min(N_VALID, len(df)), random_state=0)
        valid = valid.assign(split="valid")

    sub = pd.concat([train, valid], ignore_index=True).copy()
    if DST.exists(): shutil.rmtree(DST)
    (DST / "metadata").mkdir(parents=True, exist_ok=True)

    copied = 0
    for _, r in sub.iterrows():
        wav = str(r["wav"]).strip()
        src = (SRC_DATA / wav) if not os.path.isabs(wav) else Path(wav)
        if not src.exists():
            continue
        dest = DST / wav
        dest.parent.mkdir(parents=True, exist_ok=True)
        shutil.copy2(src, dest)
        copied += 1

    sub.to_csv(DST / "metadata" / "metadata.csv", index=False)
    print(f"Copied {copied} files. Wrote {DST / 'metadata' / 'metadata.csv'}")

if __name__ == "__main__":
    main()