using System.Linq;
using HeuristicLab.Analysis;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Operators;
using HeuristicLab.Optimization;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Algorithms.IslandALPS {
  /// <summary>
  ///   An Operator which creates a Subscope and then copies the layers from each island grouped by Layernumber into the new
  ///   scope. Then the operator executes the specified Operator on each group and afterwards deletes the created scope.
  ///   G        newScope - G
  ///   /|\          /\     /|\
  ///   I I I  =>    L1 L2  I I I
  ///   / \                 / \
  ///   L1  L2              L1 L2
  /// </summary>
  [Item("GroupedLayerOperator", "")]
  [StorableClass]
  public class GroupedLayerOperator : InstrumentedOperator {
    [StorableConstructor]
    public GroupedLayerOperator(bool deserializing) : base(deserializing) {}

    public GroupedLayerOperator(GroupedLayerOperator original, Cloner cloner) : base(original, cloner) {}

    public GroupedLayerOperator() {
      Parameters.Add(new ScopeParameter("CurrentScope", "The current scope where the operator gets executed."));
      Parameters.Add(new OperatorParameter("Operator", "The operator which should be applied on all grouped scopes."));
      //add results colletion to save the list of group result in
    }

    private ScopeParameter CurrentScopeParameter {
      get { return (ScopeParameter) Parameters["CurrentScope"]; }
    }

    private OperatorParameter OperatorParameter {
      get { return (OperatorParameter) Parameters["Operator"]; }
    }

    public IScope CurrentScope {
      get { return CurrentScopeParameter.ActualValue; }
    }

    public IOperator Operator {
      get { return OperatorParameter.Value; }
      set { OperatorParameter.Value = value; }
    }

    private IScope GroupScope {
      get {
        if (CurrentScope.Variables.ContainsKey("GroupScope")) {
          return CurrentScope.Variables["GroupScope"].Value as IScope;
        }
        var scope = new Scope();
        CurrentScope.Variables.Add(new Variable("GroupScope", scope));
        return scope;
      }
    }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new GroupedLayerOperator(this, cloner);
    }

    public override IOperation InstrumentedApply() {
      //create the subscope where the individuals get copied to.
      var scope = GroupScope;
      //descend to find the scope with individuals to copy
      foreach (var islandScope in CurrentScope.SubScopes) {
        var numScope = 0;
        foreach (var layerScope in islandScope.SubScopes) {
          //copy the individuals to the apropriate group (based on order in the ScopeTree, e.g. first layer into first group)
          IScope analyzerScope;
          if (scope.SubScopes.Count <= numScope) {
            if (!scope.SubScopes.Any()) {
              analyzerScope = new Scope();
              var rc = new ResultCollection();
              analyzerScope.Variables.Add(new Variable("GroupResults", rc));
              analyzerScope.Variables.Add(new Variable("LayerNumber", new IntValue(numScope)));
            }
            else {
              analyzerScope = scope.SubScopes.First().Clone() as IScope;
              var rc = (ResultCollection) analyzerScope.Variables["GroupResults"].Value;
              ClearHistoryRecursively(rc);
              analyzerScope.Variables["LayerNumber"].Value = new IntValue(numScope);
              //TODO: let a result collector update the lookups ?
            }

            scope.SubScopes.Add(analyzerScope);
          }
          else {
            analyzerScope = scope.SubScopes[numScope];
          }
          //delete old individuals
          analyzerScope.SubScopes.Clear();
          foreach (var individual in layerScope.SubScopes) {
            analyzerScope.SubScopes.Add(individual.Clone() as IScope);
          }
          numScope++;
        }
      }

      //execute the operator on each grouped scope
      var next = new OperationCollection(base.InstrumentedApply());
      foreach (var scopeGroup in scope.SubScopes) {
        var inner = new OperationCollection();
        inner.Add(ExecutionContext.CreateOperation(Operator, scopeGroup));
        next.Insert(0, inner);
      }


      return next;
    }

    //TODO: HL-INTEGRATION :Copied from ResultsHistoryWiper, When integrate create static apply method and delete this
    private static void ClearHistoryRecursively(ResultCollection results) {
      var values = results.Select(r => r.Value);

      // Reset all values within results in results
      foreach (var resultsCollection in values.OfType<ResultCollection>())
        ClearHistoryRecursively(resultsCollection);

      // Reset values
      foreach (var dataTable in values.OfType<DataTable>()) {
        foreach (var row in dataTable.Rows)
          for (var i = 0; i < row.Values.Count; i++)
            row.Values[i] = double.NaN;
      }
    }
  }
}