using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Globalization;
using System.Linq;
using System.Text;
using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding.Views;
using HeuristicLab.Random;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace HeuristicLab.Problems.DataAnalysis.Symbolic.Tests {
  [TestClass]
  public class BottomUpSimilarityCalculatorTest {
    private readonly BottomUpSimilarityCalculator busCalculator;
    private readonly SymbolicExpressionImporter importer;

    private const int N = 100;
    private const int Rows = 1;
    private const int Columns = 10;

    public BottomUpSimilarityCalculatorTest() {
      busCalculator = new BottomUpSimilarityCalculator();
      importer = new SymbolicExpressionImporter();
    }

    [TestMethod]
    [TestCategory("Problems.DataAnalysis.Symbolic")]
    [TestProperty("Time", "short")]
    public void TestBottomUpMatching() {
      TestMatchedNodes("(+ 1 2)", "(+ 2 1)", 5);
      TestMatchedNodes("(- 2 1)", "(- 1 2)", 2);
      TestMatchedNodes("(* (variable 1 X1) (variable 1 X2))", "(* (+ (variable 1 X1) 1) (+ (variable 1 X2) 1))", 2);

      TestMatchedNodes("(* (variable 1 X1) (variable 1 X2))", "(* (+ (variable 1 X1) 1) (variable 1 X2))", 2);

      TestMatchedNodes("(+ (variable 1 a) (variable 1 b))", "(+ (variable 1 a) (variable 1 a))", 1);
      TestMatchedNodes("(+ (+ (variable 1 a) (variable 1 b)) (variable 1 b))", "(+ (* (+ (variable 1 a) (variable 1 b)) (variable 1 b)) (+ (+ (variable 1 a) (variable 1 b)) (variable 1 b)))", 5);

      TestMatchedNodes(
        "(* (+ 2.84 (exp (+ (log (/ (variable 2.0539 X5) (variable -9.2452e-1 X6))) (/ (variable 2.0539 X5) (variable -9.2452e-1 X6))))) 2.9081)",
        "(* (- (variable 9.581e-1 X6) (+ (- (variable 5.1491e-1 X5) 1.614e+1) (+ (/ (variable 2.0539 X5) (variable -9.2452e-1 X6)) (log (/ (variable 2.0539 X5) (variable -9.2452e-1 X6)))))) 2.9081)",
        9);

      TestMatchedNodes("(+ (exp 2.1033) (/ -4.3072 (variable 2.4691 X7)))", "(/ 1 (+ (/ -4.3072 (variable 2.4691 X7)) (exp 2.1033)))", 6);
      TestMatchedNodes("(+ (exp 2.1033) (/ -4.3072 (variable 2.4691 X7)))", "(/ 1 (+ (/ (variable 2.4691 X7) -4.3072) (exp 2.1033)))", 4);
    }

    private void TestMatchedNodes(string expr1, string expr2, int expected) {
      var t1 = importer.Import(expr1);
      var t2 = importer.Import(expr2);

      var mapping = busCalculator.ComputeBottomUpMapping(t1.Root, t2.Root);
      var c = mapping.Count;

      if (c != expected) {
        throw new Exception("Match count " + c + " is different than expected value " + expected);
      }
    }

    [TestMethod]
    [TestCategory("Problems.DataAnalysis.Symbolic")]
    [TestProperty("Time", "long")]
    public void TestBottomUpSimilarityCalculatorPerformance() {
      var grammar = new TypeCoherentExpressionGrammar();
      grammar.ConfigureAsDefaultRegressionGrammar();
      var twister = new MersenneTwister(31415);
      var ds = Util.CreateRandomDataset(twister, Rows, Columns);
      var trees = Util.CreateRandomTrees(twister, ds, grammar, N, 1, 100, 0, 0);

      double s = 0;
      var sw = new Stopwatch();

      sw.Start();
      for (int i = 0; i < trees.Length - 1; ++i) {
        for (int j = i + 1; j < trees.Length; ++j) {
          s += busCalculator.CalculateSolutionSimilarity(trees[i], trees[j]);
        }
      }
      sw.Stop();
      Console.WriteLine("Elapsed time: " + sw.ElapsedMilliseconds / 1000.0 + ", Avg. similarity: " + s);
      Console.WriteLine(N * (N + 1) / (2 * sw.ElapsedMilliseconds / 1000.0) + " similarity calculations per second.");
    }

    private static string FormatMapping(ISymbolicExpressionTree t1, ISymbolicExpressionTree t2, Dictionary<ISymbolicExpressionTreeNode, ISymbolicExpressionTreeNode> map) {
      var symbolNameMap = new Dictionary<string, string>
    {
      {"ProgramRootSymbol", "Prog"},
      {"StartSymbol","RPB"},
      {"Multiplication", "$\\times$"},
      {"Division", "$\\div$"},
      {"Addition", "$+$"},
      {"Subtraction", "$-$"},
      {"Exponential", "$\\exp$"},
      {"Logarithm", "$\\log$"}
    };

      var sb = new StringBuilder();
      var nodeIds = new Dictionary<ISymbolicExpressionTreeNode, string>();
      int offset = 0;
      var layoutEngine = new ReingoldTilfordLayoutEngine<ISymbolicExpressionTreeNode>(x => x.Subtrees);
      var nodeCoordinates = layoutEngine.CalculateLayout(t1.Root).ToDictionary(n => n.Content, n => new PointF(n.X, n.Y));

      double ws = 0.5;
      double hs = 0.5;

      var nl = Environment.NewLine;
      sb.Append("\\documentclass[class=minimal,border=0pt]{standalone}" + nl +
                 "\\usepackage{tikz}" + nl +
                 "\\begin{document}" + nl +
                 "\\begin{tikzpicture}" + nl +
                 "\\def\\ws{1}" + nl +
                 "\\def\\hs{0.7}" + nl +
                 "\\def\\offs{" + offset + "}" + nl);

      foreach (var node in t1.IterateNodesBreadth()) {
        var id = Guid.NewGuid().ToString();
        nodeIds[node] = id;
        var coord = nodeCoordinates[node];
        var nodeName = symbolNameMap.ContainsKey(node.Symbol.Name) ? symbolNameMap[node.Symbol.Name] : node.ToString();
        sb.AppendLine(string.Format(CultureInfo.InvariantCulture, "\\node ({0}) at (\\ws*{1} + \\offs,\\hs*{2}) {{{3}}};", nodeIds[node], ws * coord.X, -hs * coord.Y, EscapeLatexString(nodeName)));
      }

      foreach (ISymbolicExpressionTreeNode t in t1.IterateNodesBreadth()) {
        var n = t;
        foreach (var s in t.Subtrees) {
          sb.AppendLine(string.Format(CultureInfo.InvariantCulture, "\\draw ({0}) -- ({1});", nodeIds[n], nodeIds[s]));
        }
      }

      nodeCoordinates = layoutEngine.CalculateLayout(t2.Root).ToDictionary(n => n.Content, n => new PointF(n.X, n.Y));

      offset = 20;
      sb.Append("\\def\\offs{" + offset + "}" + nl);
      foreach (var node in t2.IterateNodesBreadth()) {
        var id = Guid.NewGuid().ToString();
        nodeIds[node] = id;
        var coord = nodeCoordinates[node];
        var nodeName = symbolNameMap.ContainsKey(node.Symbol.Name) ? symbolNameMap[node.Symbol.Name] : node.ToString();
        sb.AppendLine(string.Format(CultureInfo.InvariantCulture, "\\node ({0}) at (\\ws*{1} + \\offs,\\hs*{2}) {{{3}}};", nodeIds[node], ws * coord.X, -hs * coord.Y, EscapeLatexString(nodeName)));
      }

      foreach (ISymbolicExpressionTreeNode t in t2.IterateNodesBreadth()) {
        var n = t;
        foreach (var s in t.Subtrees) {
          sb.AppendLine(string.Format(CultureInfo.InvariantCulture, "\\draw ({0}) -- ({1});", nodeIds[n], nodeIds[s]));
        }
      }

      foreach (var p in map) {
        var id1 = nodeIds[p.Key];
        var id2 = nodeIds[p.Value];

        sb.Append(string.Format(CultureInfo.InvariantCulture, "\\path[draw,->,color=gray] ({0}) edge[bend left,dashed] ({1});" + Environment.NewLine, id1, id2));
      }
      sb.Append("\\end{tikzpicture}" + nl +
                "\\end{document}" + nl);
      return sb.ToString();
    }

    private static string EscapeLatexString(string s) {
      return s.Replace("\\", "\\\\").Replace("{", "\\{").Replace("}", "\\}").Replace("_", "\\_");
    }
  }
}