/// <summary>
/// Gets the <see cref="UnitInfo"/> whose <see cref="BaseUnits"/> is a subset of <paramref name="baseUnits"/>.
/// </summary>
/// <example>Length.Info.GetUnitInfoFor(unitSystemWithFootAsLengthUnit) returns <see cref="UnitInfo" /> for <see cref="LengthUnit.Foot" />.</example>
/// <param name="baseUnits">The <see cref="BaseUnits"/> to check against.</param>
/// <returns>The <see cref="UnitInfo"/> that has <see cref="BaseUnits"/> that is a subset of <paramref name="baseUnits"/>.</returns>
/// <exception cref="ArgumentNullException"><paramref name="baseUnits"/> is null.</exception>
/// <exception cref="InvalidOperationException">No unit was found that is a subset of <paramref name="baseUnits"/>.</exception>
/// <exception cref="InvalidOperationException">More than one unit was found that is a subset of <paramref name="baseUnits"/>.</exception>
public UnitInfo GetUnitInfoFor(BaseUnits baseUnits)
{
if (baseUnits is null)
{
throw new ArgumentNullException(nameof(baseUnits));
}
var matchingUnitInfos = GetUnitInfosFor(baseUnits)
.Take(2)
.ToArray();
var firstUnitInfo = matchingUnitInfos.FirstOrDefault();
if (firstUnitInfo == null)
{
throw new InvalidOperationException($"No unit was found that is a subset of {nameof(baseUnits)}");
}
if (matchingUnitInfos.Length > 1)
{
throw new InvalidOperationException($"More than one unit was found that is a subset of {nameof(baseUnits)}");
}
return(firstUnitInfo);
}
/// <summary>
/// Gets an <see cref="IEnumerable{T}"/> of <see cref="UnitInfo"/> that have <see cref="BaseUnits"/> that is a subset of <paramref name="baseUnits"/>.
/// </summary>
/// <param name="baseUnits">The <see cref="BaseUnits"/> to check against.</param>
/// <returns>An <see cref="IEnumerable{T}"/> of <see cref="UnitInfo"/> that have <see cref="BaseUnits"/> that is a subset of <paramref name="baseUnits"/>.</returns>
/// <exception cref="ArgumentNullException"><paramref name="baseUnits"/> is null.</exception>
public IEnumerable <UnitInfo> GetUnitInfosFor(BaseUnits baseUnits)
{
if (baseUnits is null)
{
throw new ArgumentNullException(nameof(baseUnits));
}
return(UnitInfos.Where((unitInfo) => unitInfo.BaseUnits.IsSubsetOf(baseUnits)));
}