using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Encodings.RealVectorEncoding;
using HeuristicLab.Parameters;
using HeuristicLab.PDPSimulation.DomainModel;
using HeuristicLab.PDPSimulation.Operators;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.PDPSimulation {
  [Item("PriorityDispatching", "")]
  [StorableClass]
  public abstract class PriorityDispatching : Dispatching {
    [StorableConstructor]
    protected PriorityDispatching(bool deserializing) : base(deserializing) { }
    protected PriorityDispatching(PriorityDispatching original, Cloner cloner) : base(original, cloner) { }
    protected PriorityDispatching() {
    }

    protected abstract double CalculatePriority(IDictionary<string, double> variables);

    protected override void GetHighestPriorityOrder(DynPDPProblemInstance instance, Vehicle vehicle, IEnumerable<Order> orders, out Order order, out double priority) {
      Order best = null;
      double bestPriority = double.MinValue;
      var pickupOrdersByLocation = (from o in orders
                                   where IsPickup(o, instance)
                                   group o by new { X = o.PickupXCoord, Y = o.PickupYCoord })
                                   .ToDictionary(x => new XY(x.Key.X, x.Key.Y), y => y.ToArray(), new XYEqComparer());
      var deliveryOrdersByLocation = (from o in orders
                                      where !IsPickup(o, instance) && o.Vehicle == vehicle.Id
                                      group o by new { X = o.DeliveryXCoord, Y = o.DeliveryYCoord })
                                      .ToDictionary(x => new XY(x.Key.X, x.Key.Y), y => y.ToArray(), new XYEqComparer());
      var destinations = deliveryOrdersByLocation.Keys.ToArray();
      foreach (var o in orders) {
        if (IsPickup(o, instance) && o.Demand > vehicle.Capacity) continue;
        
         double prio;
         if (!IsPickup(o, instance) && vehicle.TargetPositionX == o.DeliveryXCoord && vehicle.TargetPositionY == o.DeliveryYCoord) {
           prio = double.MaxValue;
         } else {
           var target = new XY(o.PickupXCoord, o.PickupYCoord);
           if (!IsPickup(o, instance)) target = new XY(o.DeliveryXCoord, o.DeliveryYCoord);

           var destinationDifference = destinations.Select(x => scenario.DistanceMeasure.GetDistance(target.X, target.Y, x.X, x.Y)).ToArray();
           var courierDifference = GetVehicles().Where(x => x != vehicle).Select(x => new XY(x.TargetPositionX, x.TargetPositionY))
             .Select(x => scenario.DistanceMeasure.GetDistance(target.X, target.Y, x.X, x.Y)).ToArray();

           var commonDestinations = orders.Where(x => !IsPickup(x, instance) && x.Vehicle == vehicle.Id &&
                                    x.DeliveryXCoord == o.PickupXCoord &&
                                    x.DeliveryYCoord == o.PickupYCoord);

           var variables = new Dictionary<string, double>();
           variables.Add("Distance", scenario.DistanceMeasure.GetDistance(vehicle.TargetPositionX, vehicle.TargetPositionY, target.X, target.Y));
           variables.Add("EarliestTimeOfArrival", vehicle.ReadyTime + variables["Distance"]);
           variables.Add("DueDate", o.DeliveryDueTime - GetSimulationTime());
           variables.Add("StartDate", IsPickup(o, instance) ? o.PickupReadyTime - GetSimulationTime() : 0);
           variables.Add("PickupOrdersAtTarget", pickupOrdersByLocation.ContainsKey(target) ? pickupOrdersByLocation[target].Count() : 0);
           variables.Add("PickupOrderItemsAtTarget", pickupOrdersByLocation.ContainsKey(target) ? pickupOrdersByLocation[target].Sum(x => x.Demand) : 0);
           variables.Add("DeliveryOrdersAtTarget", deliveryOrdersByLocation.ContainsKey(target) ? deliveryOrdersByLocation[target].Count() : 0);
           variables.Add("DeliveryOrderItemsAtTarget", deliveryOrdersByLocation.ContainsKey(target) ? deliveryOrdersByLocation[target].Sum(x => x.Demand) : 0);
           variables.Add("AverageDistanceToDestinations", destinationDifference.Any() ? destinationDifference.Average() : 0);
           variables.Add("MinimumDistanceToDestinations", destinationDifference.Any() ? destinationDifference.Min() : 0);
           variables.Add("MaximumDistanceToDestinations", destinationDifference.Any() ? destinationDifference.Max() : 0);
           variables.Add("NumberOfOtherCouriersToTarget", GetVehicles().Count > 2 ? GetVehicles().Where(x => x != vehicle).Count(x => target.X == x.TargetPositionX && target.Y == x.TargetPositionY) : 0);
           variables.Add("AverageDistanceToOtherCouriers", courierDifference.Any() ? courierDifference.Average() : 0);
           variables.Add("MinimumDistanceToOtherCouriers", courierDifference.Any() ? courierDifference.Min() : 0);
           variables.Add("MaximumDistanceToOtherCouriers", courierDifference.Any() ? courierDifference.Max() : 0);
           variables.Add("DemandSize", o.Demand);
           variables.Add("EDD", commonDestinations.Any() ? commonDestinations.Min(d => d.DeliveryDueTime
             - scenario.DistanceMeasure.GetDistance(vehicle.TargetPositionX, vehicle.TargetPositionY, d.DeliveryXCoord, d.DeliveryYCoord)
             - GetSimulationTime()) : 0);
           variables.Add("LeadTime", o.PickupReadyTime - GetSimulationTime());

           prio = CalculatePriority(variables);
         }

        if (prio > bestPriority) {
          bestPriority = prio;
          best = o;
        }
      }

      order = best != null ? best : orders.First();
      priority = bestPriority;
    }
  }
}