using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using HeuristicLab.Common;

namespace HeuristicLab.Problems.GrammaticalOptimization {
  public class SentenceSetStatistics {
    public int NumberOfSentences { get; private set; }
    public string BestSentence { get; private set; }
    public string FirstSentence { get; private set; }
    public string LastSentence { get; private set; }
    public double BestSentenceQuality { get; private set; }
    public double BestSentenceIndex { get; private set; }
    public double FirstSentenceQuality { get; private set; }
    public double LastSentenceQuality { get; private set; }
    public double AverageQuality { get { return sumQualities / NumberOfSentences; } }
    // public double MedianQuality { get; private set; }
    private double sumQualities;

    private readonly double bestKnownQuality;
    public SentenceSetStatistics(double bestKnownQuality = 1.0) {
      this.bestKnownQuality = bestKnownQuality;
      BestSentenceQuality = double.NegativeInfinity;
      BestSentence = string.Empty;
      FirstSentence = string.Empty;
      LastSentence = string.Empty;
    }

    public void AddSentence(string sentence, double quality) {
      sumQualities += quality;
      NumberOfSentences++;

      if (NumberOfSentences == 1) {
        FirstSentence = sentence;
        FirstSentenceQuality = quality;
      }

      if (quality > BestSentenceQuality) {
        BestSentence = sentence;
        BestSentenceQuality = quality;
        BestSentenceIndex = NumberOfSentences;
      }

      LastSentence = sentence;
      LastSentenceQuality = quality;
    }

    public override string ToString() {
      return
        string.Format("Sentences: {0,10} avg.-quality {1,7:F5} best {2,7:F5} {3,2} {4,10} {5,30} first {6,7:F5} {7,20} last {8,7:F5} {9,20}",
      NumberOfSentences, AverageQuality,
      BestSentenceQuality, DoubleExtensions.IsAlmost(BestSentenceQuality, bestKnownQuality) ? 1.0 : 0.0,
      BestSentenceIndex, TrimToSize(BestSentence, 30),
      FirstSentenceQuality, TrimToSize(FirstSentence, 20),
      LastSentenceQuality, TrimToSize(LastSentence, 20)
     );
    }

    private string TrimToSize(string s, int len) {
      if (s.Length < len) return s;
      else {
        var sb = new StringBuilder(len);
        sb.Append(s.Substring(0, len - 3));
        sb.Append("...");
        return sb.ToString();
      }
    }
  }
}