using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Reflection;
using System.Text.RegularExpressions;

namespace HeuristicLab.Problems.Instances.PermutationProblems.LinearOrdering {
  public abstract class LOPInstanceProvider : ProblemInstanceProvider<LOPData> {
    public override string ReferencePublication
    {
      get { return "Martí, R., & Reinelt, G. (2011). The Linear Ordering Problem. Applied Mathematical Sciences. Springer Berlin Heidelberg. https://doi.org/10.1007/978-3-642-16729-4"; }
    }

    public override IEnumerable<IDataDescriptor> GetDataDescriptors() {
      var instanceArchiveName = GetResourceName(Name + ".zip");
      if (String.IsNullOrEmpty(instanceArchiveName)) yield break;

      using (var instanceStream = new ZipArchive(GetType().Assembly.GetManifestResourceStream(instanceArchiveName), ZipArchiveMode.Read)) {
        foreach (var entry in instanceStream.Entries.Select(x => x.Name).OrderBy(x => x)) {
          yield return new LOPDataDescriptor(Path.GetFileNameWithoutExtension(entry), GetDescription(), entry, null);
        }
      }
    }

    public override LOPData LoadData(IDataDescriptor id) {
      var descriptor = (LOPDataDescriptor)id;
      var instanceArchiveName = GetResourceName(Name + ".zip");
      using (var instancesZipFile = new ZipArchive(GetType().Assembly.GetManifestResourceStream(instanceArchiveName), ZipArchiveMode.Read)) {
        var entry = instancesZipFile.GetEntry(descriptor.InstanceIdentifier);

        using (var stream = entry.Open()) {
          var parser = new LOPParser();
          parser.Parse(stream);
          return Load(parser);
        }
      }
    }

    public override bool CanImportData
    {
      get { return true; }
    }

    public override LOPData ImportData(string path) {
      var parser = new LOPParser();
      parser.Parse(path);
      return Load(parser);
    }

    private LOPData Load(LOPParser parser) {
      var instance = new LOPData {
        Name = parser.Name,
        Description = parser.Description,
        Dimension = parser.Dimension,
        Matrix = parser.Matrix,
        BestKnownPermutation = parser.BestKnownPermutation,
        BestKnownQuality = parser.BestKnownQuality
      };
      return instance;
    }

    public override bool CanExportData
    {
      get { return false; }
    }

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

    protected virtual string GetResourceName(string fileName) {
      return Assembly.GetExecutingAssembly().GetManifestResourceNames()
        .SingleOrDefault(x => Regex.Match(x, @".*\.Data\." + fileName).Success);
    }
  }
}