#!/usr/bin/env python3
"""
Pretty-print JSON with a simple rule:

- If an object/array fits on one line within 80 characters, keep it on one line.
- Otherwise format it across multiple lines with 2-space indentation.
- Preserve key order as read from the file.

Usage:
    python jsonReadable input.json > output.json
    python jsonReadable.py input.json --inplace
"""

from __future__ import annotations

import argparse
import json
from pathlib import Path
from typing import Any


MAX_WIDTH = 120
INDENT_STEP = 2


def compact_json(value: Any) -> str:
    """Return a compact single-line JSON representation."""
    if value is None or isinstance(value, (bool, int, float, str)):
        return json.dumps(value, ensure_ascii=False, separators=(",", ": "))
    if isinstance(value, list):
        return "[" + ", ".join(compact_json(v) for v in value) + "]"
    if isinstance(value, dict):
        items = []
        for k, v in value.items():
            key = json.dumps(k, ensure_ascii=False)
            items.append(f"{key}: {compact_json(v)}")
        return "{" + ", ".join(items) + "}"
    raise TypeError(f"Unsupported JSON type: {type(value)!r}")


def pretty_json(value: Any, indent: int = 0, width: int = MAX_WIDTH) -> str:
    """Pretty-print JSON with line-length awareness."""
    if value is None or isinstance(value, (bool, int, float, str)):
        return json.dumps(value, ensure_ascii=False)

    if isinstance(value, list):
        if not value:
            return "[]"

        single_line = compact_json(value)
        if indent + len(single_line) <= width:
            return single_line

        inner_indent = " " * (indent + INDENT_STEP)
        lines = ["["]
        for i, item in enumerate(value):
            rendered = pretty_json(item, indent + INDENT_STEP, width)
            comma = "," if i < len(value) - 1 else ""
            lines.append(f"{inner_indent}{rendered}{comma}")
        lines.append(" " * indent + "]")
        return "\n".join(lines)

    if isinstance(value, dict):
        if not value:
            return "{}"

        single_line = compact_json(value)
        if indent + len(single_line) <= width:
            return single_line

        inner_indent = " " * (indent + INDENT_STEP)
        lines = ["{"]
        items = list(value.items())
        for i, (k, v) in enumerate(items):
            key = json.dumps(k, ensure_ascii=False)
            rendered = pretty_json(v, indent + INDENT_STEP, width)
            comma = "," if i < len(items) - 1 else ""
            lines.append(f"{inner_indent}{key}: {rendered}{comma}")
        lines.append(" " * indent + "}")
        return "\n".join(lines)

    raise TypeError(f"Unsupported JSON type: {type(value)!r}")


def format_json_text(text: str) -> str:
    data = json.loads(text)
    return pretty_json(data, indent=0, width=MAX_WIDTH) + "\n"


def main() -> None:
    parser = argparse.ArgumentParser(
        description="Format JSON so short objects/arrays stay on one line."
    )
    parser.add_argument("file", type=Path, help="Path to the .json file")
    parser.add_argument(
        "--inplace",
        action="store_true",
        help="Overwrite the input file instead of printing to stdout",
    )
    args = parser.parse_args()

    input_path: Path = args.file
    text = input_path.read_text(encoding="utf-8")
    formatted = format_json_text(text)

    if args.inplace:
        input_path.write_text(formatted, encoding="utf-8")
    else:
        print(formatted, end="")


if __name__ == "__main__":
    main()