from dataclasses import dataclass
from decimal import Decimal, InvalidOperation


@dataclass
class RoundingResult:
    mode: str = "EXACT"; confidence: float = 1.0; suggestion: str = ""


def detect_rounding(c: str, j: str) -> RoundingResult:
    cv = _d(c)
    jv = _d(j)
    if cv is None or jv is None:
        return RoundingResult(mode="UNKNOWN", confidence=0, suggestion="parse error")
    if cv == jv:
        return RoundingResult()
    diff = abs(float(cv - jv))
    mag = max(abs(float(cv)), abs(float(jv)), 1)
    rel = diff / mag
    if diff < 2:
        return RoundingResult("TRUNCATE", 0.6, f"Likely TRUNCATE, diff={diff}")
    if diff < 100:
        return RoundingResult("ROUNDING", 0.4, f"Possible rounding, diff={diff}")
    return RoundingResult("SIGNIFICANT", 0.9, f"Significant diff={diff}")


def _d(v):
    try:
        return Decimal(str(v).strip())
    except:
        return None