using HeuristicLab.Core;
using HeuristicLab.Data;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;

namespace HeuristicLab.Problems.Scheduling.MRCPSP {

  public static class MultiModeFileImporter {

    public static MultiModeResourceConstrainedProjectSchedulingProblem Import(string file) {
      var bounds = new Dictionary<string, int> {
        {"J501_3", 25},
        {"J502_2", 25},
        {"J502_3", 22},
        {"J502_4", 24},
        {"J502_5", 23},
        {"J504_1", 19},
        {"J504_5", 22},
        {"J507_1", 44},
        {"J507_2", 42},
        {"J507_3", 41},
        {"J507_4", 45},
        {"J507_5", 41},
        {"J508_1", 37},
        {"J508_2", 31},
        {"J508_3", 33},
        {"J508_4", 34},
        {"J508_5", 42},
        {"J509_1", 32},
        {"J509_2", 24},
        {"J509_3", 26},
        {"J509_4", 26},
        {"J509_5", 28},
        {"J5010_1", 26},
        {"J5010_2", 34},
        {"J5010_3", 26},
        {"J5010_4", 27},
        {"J5010_5", 35},
        {"J5011_1", 25},
        {"J5011_2", 28},
        {"J5011_3", 28},
        {"J5011_4", 24},
        {"J5011_5", 29},
        {"J5012_1", 26},
        {"J5012_2", 30},
        {"J5012_3", 23},
        {"J5012_4", 25},
        {"J5012_5", 25},
        {"J5020_1", 30},
        {"J5020_2", 26},
        {"J5020_4", 25},
        {"J5020_5", 25},
        {"J5021_1", 18},
        {"J5021_5", 17},
        {"J5022_1", 20},
        {"J5023_1", 17},
        {"J5023_4", 16},
        {"J5043_1", 65},
        {"J5043_2", 64},
        {"J5043_3", 68},
        {"J5043_4", 52},
        {"J5043_5", 64},
        {"J5044_1", 47},
        {"J5044_2", 41},
        {"J5044_3", 50},
        {"J5044_4", 49},
        {"J5044_5", 46},
        {"J5045_1", 46},
        {"J5045_2", 34},
        {"J5045_3", 39},
        {"J5045_4", 36},
        {"J5045_5", 44},
        {"J5046_1", 42},
        {"J5046_2", 41},
        {"J5046_3", 45},
        {"J5046_4", 31},
        {"J5046_5", 39},
        {"J5047_1", 36},
        {"J5047_2", 40},
        {"J5047_3", 42},
        {"J5047_4", 39},
        {"J5047_5", 39},
        {"J5048_1", 35},
        {"J5048_2", 40},
        {"J5048_3", 29},
        {"J5048_4", 34},
        {"J5048_5", 41},
        {"J5056_1", 35},
        {"J5056_3", 34},
        {"J5056_4", 34},
        {"J5056_5", 38},
        {"J5057_3", 31},
        {"J5058_1", 34},
        {"J5058_4", 28},
        {"J5058_5", 28},
        {"J5074_5", 57},
        {"J5079_1", 73},
        {"J5079_2", 82},
        {"J5079_3", 73},
        {"J5079_4", 68},
        {"J5079_5", 80},
        {"J5080_1", 72},
        {"J5080_2", 68},
        {"J5080_3", 82},
        {"J5080_4", 72},
        {"J5080_5", 70},
        {"J5081_1", 63},
        {"J5081_3", 57},
        {"J5081_4", 64},
        {"J5081_5", 53},
        {"J5082_1", 59},
        {"J5082_2", 60},
        {"J5082_3", 56},
        {"J5082_4", 67},
        {"J5082_5", 54},
        {"J5083_1", 49},
        {"J5083_4", 56},
        {"J5083_5", 62},
        {"J5084_1", 51},
        {"J5084_2", 57},
        {"J5084_3", 60},
        {"J5084_4", 59},
        {"J5084_5", 57},
        {"J5092_4", 60},
        {"J5094_2", 60},
        {"J5094_3", 45},
        {"J5094_4", 43},
        {"J5096_2", 48}
      };

      var instance = ParseMultiModeFile(file);
      instance.UpperBound = bounds.TryGetValue(Path.GetFileNameWithoutExtension(file), out var bound) ? bound : -1;
      return CreateProblem(instance);
    }

    private static MultiModeResourceConstrainedProjectSchedulingProblem CreateProblem(MMRCPSP instance) {
      var problem = new MultiModeResourceConstrainedProjectSchedulingProblem { Name = instance.Name };

      if (instance.UpperBound > -1) {
        problem.BestKnownQuality = instance.UpperBound;
      }

      if (instance.NbTasks != instance.Tasks.Count)
        throw new InvalidDataException();

      foreach (var task in instance.Tasks) {
        var activity = new Activity {
          Number = task.TaskId
        };

        foreach (var succ in task.Successors) {
          activity.Successors.Add(new IntValue(succ));
        }

        foreach (var mode in instance.Modes.Where(m => m.TaskId == task.TaskId)) {
          var m = new MRCPSP.Mode {
            Number = mode.ModeId,
            Duration = mode.Duration
          };

          var num = 1;
          foreach (var demand in mode.DemRenewableRsrc) {
            if (demand == 0) {
              num++;
              continue;
            }
            m.ResourceDemands.Add(new ResourceDemand { Demand = demand, Number = num++ });
          }

          foreach (var demand in mode.DemNonRenewableRsrc) {
            if (demand == 0) {
              num++;
              continue;
            }
            m.ResourceDemands.Add(new ResourceDemand { Demand = demand, Number = num++ });
          }

          activity.Modes.Add(m);
        }

        problem.Activities.Add(activity);
      }

      problem.ResourceCapacities = new ItemList<ResourceCapacity>();

      var number = 1;
      foreach (var cap in instance.CapRenewableRsrc) {
        problem.ResourceCapacities.Add(new ResourceCapacity {
          Name = $"R{number}",
          Number = number++,
          Capacity = cap,
          IsRenewable = true
        });
      }

      foreach (var cap in instance.CapNonRenewableRsrc) {
        problem.ResourceCapacities.Add(new ResourceCapacity {
          Name = $"N{number - instance.NbRenewableRsrcs}",
          Number = number++,
          Capacity = cap,
          IsRenewable = false
        });
      }

      problem.InitEncoding();
      return problem;
    }

    private static MMRCPSP ParseMultiModeFile(string filePath) {
      var result = new MMRCPSP {
        Name = Path.GetFileNameWithoutExtension(filePath),
        Tasks = new List<Task>(),
        Modes = new List<Mode>()
      };

      var section = 0;
      var prevJob = 0;

      foreach (var line in File.ReadLines(filePath).Select(l => l.Trim())) {
        if (string.IsNullOrEmpty(line))
          continue;

        if (line.StartsWith("RESOURCES")) {
          section = 1;
          continue;
        }

        if (line.StartsWith("PRECEDENCE RELATIONS")) {
          section = 2;
          continue;
        }

        if (line.StartsWith("REQUESTS/DURATIONS")) {
          section = 3;
          continue;
        }

        if (line.StartsWith("RESOURCE AVAILABILITIES") || line.StartsWith("RESOURCEAVAILABILITIES")) {
          section = 4;
          continue;
        }

        switch (section) {
          case 0: // Jobs
            if (line.StartsWith("jobs", StringComparison.InvariantCultureIgnoreCase)) {
              result.NbTasks = int.Parse(Regex.Match(line, @":[ \t]*(?<jobs>\d+)").Groups["jobs"].Value);
            }

            break;

          case 1: // Resources
            if (line.StartsWith("- nonrenewable")) {
              result.NbNonRenewableRsrcs = int.Parse(Regex.Match(line, @":.*(?<nr>\d+).*N").Groups["nr"].Value);
              result.CapNonRenewableRsrc = new int[result.NbNonRenewableRsrcs];
            } else if (line.StartsWith("- renewable")) {
              result.NbRenewableRsrcs = int.Parse(Regex.Match(line, @":.*(?<nr>\d+).*R").Groups["nr"].Value);
              result.CapRenewableRsrc = new int[result.NbRenewableRsrcs];
            }

            break;

          case 2: // Precedence Relations
            if (char.IsDigit(line[0])) {
              var numbers = line.Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);
              var task = new Task {
                TaskId = int.Parse(numbers[0]),
                Successors = new List<int>(numbers.Skip(3).Select(x => int.Parse(x)))
              };
              result.Tasks.Add(task);
            }

            break;

          case 3: // Requests/Durations
            if (char.IsDigit(line[0])) {
              var numbers = line.Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);
              var mode = new Mode {
                DemRenewableRsrc = new int[result.NbRenewableRsrcs],
                DemNonRenewableRsrc = new int[result.NbNonRenewableRsrcs]
              };
              var next = 0;
              if (numbers.Length == 3 + result.NbRenewableRsrcs + result.NbNonRenewableRsrcs) {
                prevJob = int.Parse(numbers[next++]);
              }
              mode.TaskId = prevJob;
              mode.ModeId = int.Parse(numbers[next++]);
              mode.Duration = int.Parse(numbers[next++]);
              for (var i = 0; i < result.NbRenewableRsrcs; i++) {
                mode.DemRenewableRsrc[i] = int.Parse(numbers[next++]);
              }
              for (var i = 0; i < result.NbNonRenewableRsrcs; i++) {
                mode.DemNonRenewableRsrc[i] = int.Parse(numbers[next++]);
              }
              result.Modes.Add(mode);
            }

            break;

          case 4: // Resource Availabilities
            if (char.IsDigit(line[0])) {
              var numbers = line.Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);
              var next = 0;
              for (var i = 0; i < result.NbRenewableRsrcs; i++) {
                result.CapRenewableRsrc[i] = int.Parse(numbers[next++]);
              }
              for (var i = 0; i < result.NbNonRenewableRsrcs; i++) {
                result.CapNonRenewableRsrc[i] = int.Parse(numbers[next++]);
              }
            }

            break;

          default: // unkown section
            continue;
        }
      }

      return result;
    }

    private class MMRCPSP {
      public int[] CapNonRenewableRsrc;
      public int[] CapRenewableRsrc;
      public List<Mode> Modes;
      public string Name;
      public int NbNonRenewableRsrcs;
      public int NbRenewableRsrcs;
      public int NbTasks;
      public List<Task> Tasks;
      public int UpperBound;
    }

    private class Mode {
      public int[] DemNonRenewableRsrc;
      public int[] DemRenewableRsrc;
      public int Duration;
      public int ModeId;
      public int TaskId;
    }

    private class Task {
      public List<int> Successors;
      public int TaskId;
    }
  }
}