using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using HeuristicLab.Problems.FacilityLocation;
using HeuristicLab.Problems.VehicleRouting;

namespace HeuristicLab.Networks.IntegratedOptimization.LocationRouting {
  public static class LrpUtils {
    public enum DistanceType {
      Unknown = int.MinValue,
      CEIL_2D = 0,
      EUC_2D = 1,
    }

    public static readonly Dictionary<DistanceType, Func<double[,], int, double[,], int, double>> DistanceFuncs;

    static LrpUtils() {
      DistanceFuncs = new Dictionary<DistanceType, Func<double[,], int, double[,], int, double>>();
      DistanceFuncs.Add(DistanceType.EUC_2D, (d, i, c, j) => Math.Sqrt(Math.Pow(d[i, 0] - c[j, 0], 2.0) + Math.Pow(d[i, 1] - c[j, 1], 2.0)));
      DistanceFuncs.Add(DistanceType.CEIL_2D, (d, i, c, j) => Math.Ceiling(DistanceFuncs[DistanceType.EUC_2D](d, i, c, j)) * 100);
    }

    public static void Import(string filePath, out int nrOfDepots,
                                               out int nrOfCustomers,
                                               out double[,] depotCoordinates,
                                               out double[,] customerCoordinates,
                                               out DistanceType distanceType,
                                               out double[] depotCapacities,
                                               out double[] customerDemands,
                                               out double[] depotCosts,
                                               out double vehicleCapacity,
                                               out double vehicleCost) {
      nrOfDepots = 0; nrOfCustomers = 0;
      depotCoordinates = new double[0, 0]; customerCoordinates = new double[0, 0];
      distanceType = DistanceType.Unknown;
      depotCapacities = new double[0]; customerDemands = new double[0]; depotCosts = new double[0];
      vehicleCapacity = 0.0; vehicleCost = 0.0;

      int dataIndex = 0;

      using (var fs = new FileStream(filePath, FileMode.Open))
      using (var sr = new StreamReader(fs)) {
        string input;
        while ((input = sr.ReadLine()) != null) {
          int commentCol = input.IndexOf("//");
          input = input.Substring(0, commentCol >= 0 ? commentCol : input.Length);

          if (string.IsNullOrEmpty(input)) continue;

          switch (dataIndex) {
            case 0:
              int.TryParse(input, out nrOfCustomers);
              customerCoordinates = new double[nrOfCustomers, 2];
              customerDemands = new double[nrOfCustomers];
              ++dataIndex;
              break;
            case 1:
              int.TryParse(input, out nrOfDepots);
              depotCoordinates = new double[nrOfDepots, 2];
              depotCapacities = new double[nrOfDepots];
              depotCosts = new double[nrOfDepots];
              ++dataIndex;
              break;
            case 2:
              for (int i = 0; i < nrOfDepots; i++) {
                string[] coords = input.Split('\t');
                double x; double.TryParse(coords[0], out x);
                double y; double.TryParse(coords[1], out y);
                depotCoordinates[i, 0] = x;
                depotCoordinates[i, 1] = y;
                if (i < nrOfDepots - 1)
                  input = sr.ReadLine();
              }
              ++dataIndex;
              break;
            case 3:
              for (int i = 0; i < nrOfCustomers; i++) {
                string[] coords = input.Split('\t');
                double x; double.TryParse(coords[0], out x);
                double y; double.TryParse(coords[1], out y);
                customerCoordinates[i, 0] = x;
                customerCoordinates[i, 1] = y;
                if (i < nrOfCustomers - 1)
                  input = sr.ReadLine();
              }
              ++dataIndex;
              break;
            case 4:
              double.TryParse(input, out vehicleCapacity); ++dataIndex;
              break;
            case 5:
              for (int i = 0; i < nrOfDepots; i++) {
                double capacity; double.TryParse(input, out capacity);
                depotCapacities[i] = capacity;
                if (i < nrOfDepots - 1)
                  input = sr.ReadLine();
              }
              ++dataIndex;
              break;
            case 6:
              for (int i = 0; i < nrOfCustomers; i++) {
                double demand; double.TryParse(input, out demand);
                customerDemands[i] = demand;
                if (i < nrOfCustomers - 1)
                  input = sr.ReadLine();
              }
              ++dataIndex;
              break;
            case 7:
              for (int i = 0; i < nrOfDepots; i++) {
                double cost; double.TryParse(input, out cost);
                depotCosts[i] = cost;
                if (i < nrOfDepots - 1)
                  input = sr.ReadLine();
              }
              ++dataIndex;
              break;
            case 8: double.TryParse(input, out vehicleCost); ++dataIndex; break;
            case 9: Enum.TryParse(input, out distanceType); break;
          }
        }
      }
    }

    public static double[,] GetFlpDeliveryCosts(double[,] depotCoordinates, double[,] customerCoordinates, DistanceType distanceType) {
      int nrOfDepots = depotCoordinates.GetLength(0), nrOfCustomers = customerCoordinates.GetLength(0);
      var deliveryCosts = new double[nrOfDepots, nrOfCustomers];

      for (int i = 0; i < nrOfDepots; i++)
        for (int j = 0; j < nrOfCustomers; j++)
          deliveryCosts[i, j] = DistanceFuncs[distanceType](depotCoordinates, i, customerCoordinates, j);

      return deliveryCosts;
    }

    public static double[,] GetVrpCoordinates(double[,] depotCoordinates, double[,] customerCoordinates, int depotIdx, int[] customers) {
      var coordinates = new double[customers.Length + 1, 2];

      coordinates[0, 0] = depotCoordinates[depotIdx, 0];
      coordinates[0, 1] = depotCoordinates[depotIdx, 1];
      for (int i = 0; i < customers.Length; i++) {
        coordinates[i + 1, 0] = customerCoordinates[customers[i], 0];
        coordinates[i + 1, 1] = customerCoordinates[customers[i], 1];
      }

      return coordinates;
    }

    public static double[,] GetVrpDistances(double[,] depotCoordinates, double[,] customerCoordinates, int depotIdx, int[] customers, DistanceType distanceType) {
      var coordinates = GetVrpCoordinates(depotCoordinates, customerCoordinates, depotIdx, customers);
      return GetVrpDistances(coordinates, distanceType);
    }

    public static double[,] GetVrpDistances(double[,] coordinates, DistanceType distanceType) {
      int nrOfNodes = coordinates.GetLength(0);
      var distances = new double[nrOfNodes, nrOfNodes];

      for (int i = 1; i < nrOfNodes; i++)
        for (int j = 0; j < i; j++)
          distances[i, j] = distances[j, i] = DistanceFuncs[distanceType](coordinates, i, coordinates, j);

      return distances;
    }

    public static double Evaluate(FacilityLocationSolution flpSolution, VRPSolution[] vrpSolutions) {
      return flpSolution.TotalOpeningCostsParameter.Value.Value + vrpSolutions.Sum(x => x.Quality.Value);
    }
  }
}