#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2012 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.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text.RegularExpressions;

namespace HeuristicLab.Problems.Instances.TSPLIB {
  public class TSPLIBTSPInstanceProvider : ProblemInstanceProvider<ITSPInstance> {
    
    public override string Name {
      get { return "TSPLIB (symmetric TSP)"; }
    }

    public override string Description {
      get { return "Traveling Salesman Problem Library"; }
    }

    public override Uri Link {
      get { return new Uri("http://comopt.ifi.uni-heidelberg.de/software/TSPLIB95/"); }
    }

    public override IEnumerable<IInstanceDescriptor> GetInstanceDescriptors() {
      var solutions = Assembly.GetExecutingAssembly()
        .GetManifestResourceNames()
        .Where(x => x.EndsWith(".opt.tour"))
        .ToDictionary(x => x.Substring(0, x.Length - ".opt.tour".Length) + ".tsp", x => x);

      return Assembly.GetExecutingAssembly()
          .GetManifestResourceNames()
          .Where(x => x.EndsWith(".tsp"))
          .OrderBy(x => x)
          .Select(x => new TSPLIBInstanceDescriptor(GetPrettyName(x), GetDescription(), x, solutions.ContainsKey(x) ? solutions[x] : String.Empty));
    }

    public override ITSPInstance GetInstance(IInstanceDescriptor id) {
      var descriptor = (TSPLIBInstanceDescriptor)id;
      var instance = new TSPLIBInstance();
      using (var stream = Assembly.GetExecutingAssembly()
        .GetManifestResourceStream(descriptor.InstanceIdentifier)) {
        var tspParser = new TSPLIBParser(stream);
        tspParser.Parse();
        instance.Coordinates = tspParser.Vertices != null ? tspParser.Vertices : tspParser.DisplayVertices;
        instance.Distances = tspParser.Distances;

        instance.Name = tspParser.Name;
        instance.Description = tspParser.Comment
          + Environment.NewLine + Environment.NewLine
          + GetDescription();

        if (!String.IsNullOrEmpty(descriptor.SolutionIdentifier)) {
          using (Stream solStream = Assembly.GetExecutingAssembly()
            .GetManifestResourceStream(descriptor.SolutionIdentifier)) {
            var slnParser = new TSPLIBParser(solStream);
            slnParser.Parse();
            instance.BestKnownTour = slnParser.Tour[0];
          }
        }
      }
      return instance;
    }

    private string GetPrettyName(string instanceIdentifier) {
      return Regex.Match(instanceIdentifier, GetType().Namespace + @"\.Data\.TSP\.(.*)\.tsp").Groups[1].Captures[0].Value;
    }

    private string GetDescription() {
      return "Embedded instance of plugin version " + Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(AssemblyFileVersionAttribute), true).Cast<AssemblyFileVersionAttribute>().First().Version + ".";
    }
  }
}