using System;
using System.Diagnostics;
using System.Linq;
using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
using HeuristicLab.Problems.DataAnalysis.Symbolic;
using HeuristicLab.Random;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace HeuristicLab.EvolutionTracking.Tests {
  [TestClass]
  public class QueryMatchPerformanceTest {
    private const int MaxDepth = 12;
    private const int MaxLength = 50;
    private const int N = 50000;
    private const int Repetitions = 5;

    [TestMethod]
    public void TestQueryMatchPerformance() {
      var grammar = new TypeCoherentExpressionGrammar();
      grammar.ConfigureAsDefaultRegressionGrammar();
      var creator = new ProbabilisticTreeCreator();
      var random = new MersenneTwister();

      var trees = Enumerable.Range(0, N).Select(x => creator.CreateTree(random, grammar, MaxLength, MaxDepth)).ToList();
      var comparer = new SymbolicExpressionTreeNodeEqualityComparer {
        MatchConstantValues = false,
        MatchVariableWeights = false,
        MatchVariableNames = true
      };
      var qm = new QueryMatch(comparer) { MatchParents = true };
      // warmup
      int count = trees.Skip(1).Count(x => qm.Match(x, trees[0]));

      var sw = new Stopwatch();
      sw.Start();
      for (int i = 0; i < Repetitions; ++i)
        count = trees.Skip(1).Count(x => x.Length >= trees[0].Length && qm.Match(x, trees[0]));
      sw.Stop();

      Console.WriteLine("Count: " + count);
      Console.WriteLine("Query matches per second: " + (N - 1) / (sw.ElapsedMilliseconds / 1000.0) * Repetitions);
      Console.WriteLine("Total time: " + sw.ElapsedMilliseconds / 1000.0 + "s");

      sw.Restart();
      for (int i = 0; i < Repetitions; ++i)
        count = qm.GetMatchingTrees(trees.Skip(1), trees[0]).Count();
      sw.Stop();

      Console.WriteLine("Count: " + count);
      Console.WriteLine("Optimized query matches per second: " + (N - 1) / (sw.ElapsedMilliseconds / 1000.0) * Repetitions);
      Console.WriteLine("Total time: " + sw.ElapsedMilliseconds / 1000.0 + "s");
    }
  }
}