using ReportGenerator.Generator.Abstract;
using ReportGenerator.Generator.Interface;
using ReportGenerator.Generator.Model;
using ReportGenerator.Models;

namespace ReportGenerator;

public class ReportGenerator : FileSerializableBase
{
  /// <inheritdoc />
  public override string FileExtension => Document.FileExtension;

  private IDocumentGenerator Document { get; }

  private ICollection<ImageStats> Images { get; }

  public ReportGenerator(
    IDocumentGenerator document,
    IEnumerable<ImageStats> data
  )
  {
    Document = document;
    Images = data.ToArray();
  }

  public ReportGenerator(
    string title,
    IDocumentGenerator document,
    IEnumerable<ImageStats> data
  ) : this(document, data)
  {
    WithTitle(title);
  }

  /// <inheritdoc />
  public override string ToString() => Document.ToString();

  #region Report content generation

  public ReportGenerator WithTitle(string text)
  {
    Document.AppendHeading(1, text);
    return this;
  }

  public ReportGenerator AddImageStatsFull(string title)
  {
    Document.AppendHeading(2, title);

    foreach (var stat in Images)
    {
      Document
        .AppendHeading(3, stat.ImageName)
        .AppendParagraph(
          Document.FormatImage(Path.Combine("img", stat.ImageName), new Bounds(0, 350))
        )
        .AppendTable(
          stat.Reference.Count + 5,
          table =>
          {
            table.AppendHeader(stat
              .Reference
              .Prepend("Image")
              .Prepend("CER (avg)")
              .Prepend("WER")
              .Prepend("Elapsed")
              .Prepend("Processor")
            );

            var processors = stat.Processors
              .OrderBy(s => s.Distance)
              .ThenBy(s => s.ProcessingTime);

            foreach (var processor in processors)
            {
              var imgPath = Path.Combine("results", $"{processor.Name}.00.{stat.ImageName}.png");

              table.AppendRow(processor.Words
                .Select(s => s.ToString() ?? string.Empty)
                .Prepend(Document.FormatImage(imgPath, new Bounds(0, 150)))
                .Prepend(processor.Words.Average(s => s.Distance).ToString("F2"))
                .Prepend($"{processor.Distance * 100:F1}%")
                .Prepend($"{processor.ProcessingTime * 1000:F1}ms")
                .Prepend(processor.Name)
              );
            }
          })
        .AppendParagraph(
          $"*Comparison data generated based on {stat.Reference.Count} tagged words.*"
        );
    }

    return this;
  }

  public ReportGenerator AddComparison(
    string title,
    Func<IEnumerable<double>, double> evaluationFunc
  )
  {
    var lookup = Images
      .SelectMany(s => s.Processors)
      .ToLookup(p => p.Name);

    Document.AppendHeading(2, title);

    var byWer = lookup
      .Select(g => (
        Name: g.Key,
        Value: evaluationFunc(g.Select(p => p.Distance)) * 100
      ))
      .OrderBy(g => g.Value);
    Document.AppendHeading(3, "WER");
    AppendComparison(("Error", "%"), byWer);

    var byCer = lookup
      .Select(g => (
        Name: g.Key,
        Value: evaluationFunc(g.SelectMany(p => p.Words, (_, word) => word.Distance))
      ))
      .OrderBy(g => g.Value);
    Document.AppendHeading(3, "CER");
    AppendComparison(("Changes", string.Empty), byCer);

    var byTime = lookup
      .Select(g => (
        Name: g.Key,
        Value: evaluationFunc(g.Select(p => p.ProcessingTime)) * 1000
      ))
      .OrderBy(g => g.Value);
    Document.AppendHeading(3, "Time");
    AppendComparison(("Time", "ms"), byTime);

    return this;
  }


  private void AppendComparison(
    (string name, string unit)? valueInfo,
    IEnumerable<(string, double)> values
  )
  {
    const int context = 5;

    var tValues = values.ToArray();
    var tContext = Math.Min(tValues.Length / 2, context);

    Document.AppendTable(2, table =>
    {
      table
        .AppendHeader(new[] { "Processor", valueInfo?.name ?? "Value" })
        .AppendRows(tValues
          .Take(tContext)
          .Select(MakeRow))
        .AppendRow("...")
        .AppendRows(
          tValues
            .TakeLast(tContext)
            .Select(MakeRow)
        );

      return;

      string[] MakeRow((string, double) v) =>
        new[] { v.Item1, v.Item2.ToString("F2") + valueInfo?.unit };
    });
  }

  #endregion
}