#!/usr/bin/env python3.12

import argparse
import sys
from pathlib import Path


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(
        description="Rename Gramps document files by appending extensions from a list."
    )
    parser.add_argument("directory", type=Path, help="Directory containing hashed files")
    parser.add_argument("names_file", type=Path, help="Text file with target names")
    return parser.parse_args()


def read_names(path: Path) -> list[str]:
    if not path.is_file():
        raise FileNotFoundError(f"Names file not found: {path}")

    names = []
    for line in path.read_text(encoding="utf-8").splitlines():
        name = line.strip()
        if name:
            names.append(name)
    return names


def rename_files(directory: Path, names: list[str]) -> None:
    if not directory.is_dir():
        raise NotADirectoryError(f"Directory not found: {directory}")

    for name in names:
        hash_part, dot, _ = name.partition(".")
        if not dot:
            print(f"Skipping invalid entry (missing extension): {name}", file=sys.stderr)
            continue

        source = directory / hash_part
        target = directory / name

        if target.exists():
            print(f"Target already exists, skipping: {target}", file=sys.stderr)
            continue

        if not source.exists():
            print(f"Source not found, skipping: {source}", file=sys.stderr)
            continue

        source.rename(target)
        print(f"Renamed {source.name} -> {target.name}")


def main() -> None:
    args = parse_args()
    try:
        names = read_names(args.names_file)
        rename_files(args.directory, names)
    except Exception as exc:  # noqa: BLE001
        print(str(exc), file=sys.stderr)
        sys.exit(1)


if __name__ == "__main__":
    main()