"""python -m geometry observations.json [-o result.json]"""

import argparse
import json
from dataclasses import replace
from math import isfinite
from pathlib import Path
from .localization import Measurement, solve


def main():
    parser = argparse.ArgumentParser(description="B题问题一：角域交、直径与包围圆")
    parser.add_argument("input", type=Path, help="包含measurements数组的JSON文件")
    parser.add_argument("-o", "--output", type=Path)
    parser.add_argument("--rounding-margin-deg", type=float, default=0,
                        help="额外误差半角，默认0；可显式设0.005进行舍入敏感性分析")
    args = parser.parse_args()
    try:
        source = json.loads(args.input.read_text(encoding="utf-8-sig"))
        measurements = [Measurement(**row) for row in source["measurements"]]
        if not isfinite(args.rounding_margin_deg) or args.rounding_margin_deg < 0:
            raise ValueError("额外误差半角必须为有限非负数")
        measurements = [replace(m, half_angle_deg=m.half_angle_deg+args.rounding_margin_deg)
                        for m in measurements]
        result = solve(measurements)
        result["error_policy"] = {"additional_half_angle_deg": args.rounding_margin_deg,
                                  "effective_half_angles_deg": [m.half_angle_deg for m in measurements]}
    except (ValueError, TypeError, KeyError, OSError) as exc:
        parser.error(str(exc))
    text = json.dumps(result, ensure_ascii=False, indent=2, allow_nan=False)
    if args.output:
        args.output.parent.mkdir(parents=True, exist_ok=True)
        args.output.write_text(text + "\n", encoding="utf-8")
    print(text)


if __name__ == "__main__":
    main()