#!/usr/bin/env python3
"""
generate_checksums.py
=====================
Generates SHA-256 checksums for all data files in the MatchGeo dataset.

Usage:
  python generate_checksums.py --data-root /path/to/MatchGeo-DEM-v1 --output checksums.sha256
"""

import hashlib
import argparse
from pathlib import Path


def sha256_file(filepath):
    """Return SHA-256 hex digest of a file."""
    h = hashlib.sha256()
    with open(filepath, "rb") as f:
        for chunk in iter(lambda: f.read(8192 * 1024), b""):
            h.update(chunk)
    return h.hexdigest()


def main():

    data_root = "/home/sabrina/Documents/Tese/05_Dataset/MatchGeo-DEM-v1"
    output = "checksums.sha256"
    include = [".tif", ".json", ".geojson", ".csv", ".qmd", ".cff", ".md"]


    data_root = Path(data_root)
    output_path = Path(output)

    print("=" * 60)
    print("MatchGeo-DEM Checksum Generator")
    print("=" * 60)

    entries = []
    for ext in include:
        for filepath in sorted(data_root.rglob(f"*{ext}")):
            if ".git" in str(filepath):
                continue
            rel = filepath.relative_to(data_root)
            digest = sha256_file(filepath)
            entries.append(f"{digest}  {rel}")
            print(f"   {rel}")

    output_path.write_text("\n".join(entries) + "\n", encoding="utf-8")
    print(f"\n✅ {len(entries)} files hashed → {output_path}")
    print("=" * 60)


if __name__ == "__main__":
    main()