using Common.Distance;

namespace ReportGenerator.Models;

public readonly struct ProcessorStat : IDistanceComparer<IEnumerable<string>>
{
  /// <summary>
  /// The name of the processor
  /// </summary>
  public string Name { get; }

  /// <summary>
  /// The total milliseconds it took the processor to process the data
  /// </summary>
  public double ProcessingTime { get; }

  /// <inheritdoc />
  public IEnumerable<string> Reference { get; }

  /// <inheritdoc />
  public IEnumerable<string>? Hypothesis { get; }

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

  /// <summary>
  /// Information about the processed values
  /// </summary>
  public ICollection<IDistanceComparer<string>> Words { get; }

  public ProcessorStat(
    string name,
    double processingTime,
    ICollection<string> reference,
    ICollection<string> hypothesis
  )
  {
    Name = name;
    ProcessingTime = processingTime;

    Reference = reference;
    Hypothesis = hypothesis;

    Distance = Calculator.GetDistance(
      reference.OrderBy(s => s).ToArray(),
      hypothesis.OrderBy(s => s).ToArray()
    ) / reference.Count;

    Words = reference.Select(r => GetDistanceInfo(r, hypothesis)).ToArray();
  }

  private static ICollection<IDistanceComparer<string>> GetDistanceInfos(
    ICollection<string> reference,
    ICollection<string> hypothesis
  )
  {
    // todo avoid matching the same reference with a value multiple times
    throw new NotImplementedException();
  }

  /// <summary>
  /// Compares the <paramref name="reference"/> with all given <paramref name="values"/>
  /// and determines the <see cref="IDistanceComparer{T}"/> with the lowest error
  /// </summary>
  private static IDistanceComparer<string> GetDistanceInfo(
    string reference,
    IEnumerable<string> values
  )
  {
    var result = new DistanceComparer<string>(reference);

    // Determine character stat with lowest error
    foreach (var value in values)
    {
      // todo avoid matching the same reference with a value multiple times

      var stat = new DistanceComparer<string>(reference, value);
      if (stat.Distance > result.Distance || (stat.Distance / reference.Length) > 0.6d)
      {
        // todo fine-tune threshold
        continue;
      }

      result = stat;

      if (stat.Distance <= 0)
      {
        // We cannot go lower than zero, break
        return result;
      }
    }

    return result;
  }
}