#!/usr/bin/env python3
"""A tiny JSON pretty-printer."""

import argparse
import json
import sys
from pathlib import Path
from typing import Any, Sequence


def pretty_json(text: str, *, indent: int = 2, sort_keys: bool = False) -> str:
    """Parse JSON text and return a consistently formatted representation."""
    value: Any = json.loads(text)
    return json.dumps(value, indent=indent, sort_keys=sort_keys, ensure_ascii=False)


def main(argv: Sequence[str] | None = None) -> int:
    parser = argparse.ArgumentParser(description="Pretty-print JSON.")
    parser.add_argument("file", nargs="?", type=Path, help="input file; defaults to stdin")
    parser.add_argument("-i", "--indent", type=int, default=2)
    parser.add_argument("-s", "--sort-keys", action="store_true")
    args = parser.parse_args(argv)

    try:
        text = args.file.read_text(encoding="utf-8") if args.file else sys.stdin.read()
        print(pretty_json(text, indent=args.indent, sort_keys=args.sort_keys))
    except (OSError, json.JSONDecodeError) as error:
        print(f"error: {error}", file=sys.stderr)
        return 1

    return 0


# Small pytest-compatible checks.
def test_pretty_json_indents_nested_values() -> None:
    assert pretty_json('{"a":[1,true]}') == '{\n  "a": [\n    1,\n    true\n  ]\n}'


def test_pretty_json_sorts_keys() -> None:
    assert pretty_json('{"z":1,"a":2}', sort_keys=True).index('"a"') < pretty_json(
        '{"z":1,"a":2}', sort_keys=True
    ).index('"z"')


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