#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2015 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;

namespace HeuristicLab.Problems.GeneticProgramming.Robocode {
  public static class Interpreter {
    public static double EvaluateTankProgram(ISymbolicExpressionTree tree, string path, EnemyCollection enemies, string robotName = null, bool showUI = false, int nrOfRounds = 3) {
      if (robotName == null)
        robotName = GenerateRobotName();

      string interpretedProgram = InterpretProgramTree(tree.Root, robotName);
      string battleRunnerPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
      string roboCodeLibPath = Path.Combine(path, "libs");
      string robocodeJar = Path.Combine(roboCodeLibPath, "robocode.jar");
      string robocodeCoreJar = GetFileName(roboCodeLibPath, "robocode.core*");
      string picocontainerJar = GetFileName(roboCodeLibPath, "picocontainer*");
      string robotsPath = Path.Combine(path, "robots", "Evaluation");
      string srcRobotPath = Path.Combine(robotsPath, robotName + ".java");

      File.WriteAllText(srcRobotPath, interpretedProgram, System.Text.Encoding.Default);

      // compile java source to class file
      ProcessStartInfo javaCompileInfo = new ProcessStartInfo();
      javaCompileInfo.FileName = "cmd.exe";
      javaCompileInfo.Arguments = "/C javac -cp " + robocodeJar + "; " + srcRobotPath;
      javaCompileInfo.RedirectStandardOutput = true;
      javaCompileInfo.RedirectStandardError = true;
      javaCompileInfo.UseShellExecute = false;
      javaCompileInfo.CreateNoWindow = true;

      using (Process javaCompile = new Process()) {
        javaCompile.StartInfo = javaCompileInfo;
        javaCompile.Start();

        string cmdOutput = javaCompile.StandardOutput.ReadToEnd();
        cmdOutput += javaCompile.StandardError.ReadToEnd();

        javaCompile.WaitForExit();
        if (javaCompile.ExitCode != 0) {
          DeleteRobotFiles(path, robotName);
          throw new Exception("Compile Error: " + cmdOutput);
        }
      }

      //parallel execution of multiple robocode instances can sometimes lead to a damaged robot.database
      var robotsDbFileName = Path.Combine(path, "robots", "robot.database");
      if (File.Exists(robotsDbFileName))
        File.Delete(robotsDbFileName);

      ProcessStartInfo evaluateCodeInfo = new ProcessStartInfo();

      // execute a battle with numberOfRounds against a number of enemies
      // TODO: seems there is a bug when selecting multiple enemies
      evaluateCodeInfo.FileName = "cmd.exe";
      var classpath = string.Join(";", new[] { battleRunnerPath, robocodeCoreJar, robocodeJar, picocontainerJar });
      var enemyRobotNames = string.Join(" ", enemies.CheckedItems.Select(i => i.Value));
      evaluateCodeInfo.Arguments = string.Format("/C java -cp {0} BattleRunner Evaluation.{1} {2} {3} {4} {5}", classpath, robotName, path, showUI, nrOfRounds, enemyRobotNames);

      evaluateCodeInfo.RedirectStandardOutput = true;
      evaluateCodeInfo.RedirectStandardError = true;
      evaluateCodeInfo.UseShellExecute = false;
      evaluateCodeInfo.CreateNoWindow = true;

      double evaluation;
      using (Process evaluateCode = new Process()) {
        evaluateCode.StartInfo = evaluateCodeInfo;
        evaluateCode.Start();
        evaluateCode.WaitForExit();

        if (evaluateCode.ExitCode != 0) {
          DeleteRobotFiles(path, robotName);
          throw new Exception("Error running Robocode: " + evaluateCode.StandardError.ReadToEnd() + Environment.NewLine +
                              evaluateCode.StandardOutput.ReadToEnd());
        }

        try {
          string scoreString =
            evaluateCode.StandardOutput.ReadToEnd()
              .Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries)
              .Last();
          evaluation = Double.Parse(scoreString, CultureInfo.InvariantCulture);
        }
        catch (Exception ex) {
          throw new Exception("Error parsing score string: " + ex);
        }
        finally {
          DeleteRobotFiles(path, robotName);
        }
      }

      return evaluation;
    }

    private static void DeleteRobotFiles(string path, string outputname) {
      File.Delete(path + @"\robots\Evaluation\" + outputname + ".java");
      File.Delete(path + @"\robots\Evaluation\" + outputname + ".class");
    }

    private static string GetFileName(string path, string pattern) {
      string fileName = string.Empty;
      try {
        fileName = Directory.GetFiles(path, pattern).First();
      }
      catch {
        throw new Exception("Error finding required Robocode files.");
      }
      return fileName;
    }

    private static string GenerateRobotName() {
      // Robocode class names are 32 char max and 
      // Java class names have to start with a letter
      string outputname = Guid.NewGuid().ToString();
      outputname = outputname.Remove(8, 1);
      outputname = outputname.Remove(12, 1);
      outputname = outputname.Remove(16, 1);
      outputname = outputname.Remove(20, 1);
      outputname = outputname.Remove(0, 1);
      outputname = outputname.Insert(0, "R");
      return outputname;
    }

    public static string InterpretProgramTree(ISymbolicExpressionTreeNode node, string robotName) {
      var tankNode = node;
      while (!(tankNode.Symbol is Tank))
        tankNode = tankNode.GetSubtree(0);

      string result = ((CodeNode)tankNode.Symbol).Interpret(tankNode, tankNode.Subtrees);
      result = result.Replace("class output", "class " + robotName);
      return result;
    }
  }
}