JensKrumsieck/ChemSharp

using ChemSharp.Extensions;

namespace ChemSharp.UnitConversion;

public abstract class AbstractUnitConverter
{
    internal string _fromKey;
    internal string _toKey;

    protected AbstractUnitConverter(string from, string to)
    {
        _fromKey = from;
        _toKey = to;
    }

    protected Dictionary<string, MappedFunction> SIUnitLookup { get; } = new();

    /// <summary>
    ///     Add new Conversion to Lookup
    /// </summary>
    /// <param name="unit"></param>
    /// <param name="converter"></param>
    public void AddConversion(string unit, MappedFunction converter) => SIUnitLookup.Add(unit, converter);

    /// <summary>
    ///     Addd new Conversion
    /// </summary>
    /// <param name="unit"></param>
    /// <param name="factor"></param>
    public void AddConversion(string unit, double factor) =>
        AddConversion(unit, new MappedFunction {Function = s => s * factor, Reciprocal = false});

    internal double Conversion(string from, string to, double val)
    {
        var baseUnit = SIUnitLookup.TryAndGet(from).Function(val);
        var mfunc = SIUnitLookup.TryAndGet(to);
        var toVal = baseUnit / mfunc.Function(1);
        return mfunc.Reciprocal ? 1 / toVal : toVal;
    }

    /// <summary>
    ///     Converts from left to right (from -> to)
    /// </summary>
    /// <returns></returns>
    public double Convert(double value) => Conversion(_fromKey, _toKey, value);

    /// <summary>
    ///     Converts inverted (right to left, to -> from)
    /// </summary>
    /// <returns></returns>
    public double ConvertInverted(double value) => Conversion(_toKey, _fromKey, value);
}