81 lines
2.2 KiB
Python
81 lines
2.2 KiB
Python
from __future__ import annotations
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from decimal import Decimal, InvalidOperation, ROUND_HALF_UP
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FUEL_FACTORS: list[tuple[str, Decimal]] = [
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("HTPB", Decimal("0.00177")),
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("Solid", Decimal("0.00178")),
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("PBAN", Decimal("0.001772")),
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("Kerolox", Decimal("0.0010290673")),
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("Hydrolox", Decimal("0.00036235886")),
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("Methalox", Decimal("0.000845043157")),
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("Hydrazine", Decimal("0.001004")),
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("MMH/NTO", Decimal("0.00116557")),
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]
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FUEL_DENSITY_T_PER_LITER = dict(FUEL_FACTORS)
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VALUE_STEP = Decimal("0.000001")
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def list_fuel_factors() -> list[dict[str, float | str]]:
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return [
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{"fuel": fuel, "tonnes_per_liter": _to_float(factor)}
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for fuel, factor in FUEL_FACTORS
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]
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def convert_value(mode: str, raw_value: object) -> dict[str, object]:
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value = _parse_positive_decimal(raw_value)
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normalized_mode = mode.strip().lower()
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if normalized_mode == "volume":
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results = [
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{
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"fuel": fuel,
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"value": _to_float(value * factor),
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"unit": "t",
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}
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for fuel, factor in FUEL_FACTORS
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]
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return {
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"mode": normalized_mode,
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"input_value": _to_float(value),
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"input_unit": "L",
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"results": results,
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}
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if normalized_mode == "mass":
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results = [
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{
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"fuel": fuel,
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"value": _to_float(value / factor),
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"unit": "L",
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}
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for fuel, factor in FUEL_FACTORS
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]
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return {
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"mode": normalized_mode,
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"input_value": _to_float(value),
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"input_unit": "t",
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"results": results,
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}
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raise ValueError("mode must be either 'volume' or 'mass'")
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def _parse_positive_decimal(raw_value: object) -> Decimal:
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try:
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value = Decimal(str(raw_value))
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except (InvalidOperation, ValueError, TypeError) as exc:
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raise ValueError("value must be numeric") from exc
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if value <= 0:
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raise ValueError("value must be greater than zero")
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return value
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def _to_float(value: Decimal) -> float:
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return float(value.quantize(VALUE_STEP, rounding=ROUND_HALF_UP))
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