#!/usr/bin/env python3
# Author: Simon-Pierre Boucher — contact@spboucher.ai
"""Step 01 — Build the estimation sample.

Reads the raw matched transaction–roll snapshot
(``data/raw/transactions_700k_avec_registre_foncier.parquet``), keeps
residential arm's-length sales with a high-confidence roll match, constructs
the assessment ratio and derived regressors, applies the trims, and writes
``data/processed/analysis.parquet``.

Usage:  python scripts/01_build_sample.py
"""
import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "src"))

from wp10 import sample  # noqa: E402


def main() -> None:
    s = sample.build_and_save()
    print(f"\nEstimation sample written: {len(s):,} sales")
    print(f"  municipalities : {s['muni'].nunique():,}")
    print(f"  cells          : {s['cell'].nunique():,}")
    print(f"  classes        : {s.groupby('prop_class').size().to_dict()}")
    print(f"  median ratio   : {s['ratio'].median():.3f}")


if __name__ == "__main__":
    main()