using System.Collections;

namespace Common.Distance;

public readonly struct DistanceComparer<T> : IDistanceComparer<T>
  where T : IEnumerable
{
  /// <inheritdoc />
  public T Reference { get; }

  /// <inheritdoc />
  public T? Hypothesis { get; }

  /// <inheritdoc />
  public double Distance { get; }

  public DistanceComparer(T reference) : this(reference, default)
  {
  }

  public DistanceComparer(T reference, T? hypothesis)
  {
    Reference = reference;
    Hypothesis = hypothesis;

    Distance = Calculator.GetDistance(Reference, Hypothesis);
  }


  /// <inheritdoc />
  public override string ToString()
  {
    var str = Hypothesis?.ToString();

    if (Hypothesis is var hyp && Equals(hyp, Reference))
    {
      return str ?? string.Empty;
    }

    return
      $"<strong style='color: orange;' title='REf: {Reference}, CER: {Distance}'>{str ?? "-"}</strong>";
  }
}