"""A small CLI that prints a configurable greeting."""

from __future__ import annotations

import argparse
import doctest
from collections.abc import Sequence


def build_greeting(name: str, excited: bool = False) -> str:
    """Build a greeting.

    >>> build_greeting("Ada")
    'Hello, Ada.'
    >>> build_greeting("Grace", excited=True)
    'Hello, Grace!'
    """
    punctuation = "!" if excited else "."
    return f"Hello, {name}{punctuation}"


def parse_args(argv: Sequence[str] | None = None) -> argparse.Namespace:
    """Parse command-line arguments."""
    parser = argparse.ArgumentParser(description="Print a friendly greeting.")
    parser.add_argument("name", help="name of the person to greet")
    parser.add_argument(
        "-n",
        "--count",
        type=int,
        default=1,
        help="number of greetings to print (default: 1)",
    )
    parser.add_argument(
        "--excited",
        action="store_true",
        help="end the greeting with an exclamation mark",
    )
    parser.add_argument(
        "--test",
        action="store_true",
        help="run the embedded tests before printing",
    )
    args = parser.parse_args(argv)

    if args.count < 1:
        parser.error("--count must be at least 1")

    return args


def main(argv: Sequence[str] | None = None) -> int:
    """Run the command-line program."""
    args = parse_args(argv)

    if args.test:
        failures, _ = doctest.testmod()
        if failures:
            return 1

    greeting = build_greeting(args.name, args.excited)
    for _ in range(args.count):
        print(greeting)

    return 0


if __name__ == "__main__":
    raise SystemExit(main())