using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using HeuristicLab.Core;
using HeuristicLab.DataAnalysis;
using System.Xml;

namespace HeuristicLab.Functions {
  public class FunctionTree : ItemBase, IFunctionTree {

    private List<IFunctionTree> subTrees;
    private List<IVariable> localVariables;
    private IFunction function;

    public FunctionTree() : base() {
      subTrees = new List<IFunctionTree>();
      localVariables = new List<IVariable>();
    }

    public FunctionTree(IFunction function) : this() {
      this.function = function;
      // create and store clones of all local variables of the function
      foreach(VariableInfo info in function.VariableInfos) {
        if(info.Local) {
          AddVariable((IVariable)function.GetVariable(info.FormalName).Clone());
        }
      }
    }

    #region IFunctionTree Members

    public IList<IFunctionTree> SubTrees {
      get { return subTrees.AsReadOnly(); }
    }

    public ICollection<IVariable> LocalVariables {
      get { return localVariables.AsReadOnly(); }
    }

    public IFunction Function {
      get { return function; }
    }

    public IVariable GetLocalVariable(string name) {
      foreach(IVariable var in localVariables) {
        if(var.Name == name) return var;
      }
      return null;
    }

    public void AddVariable(IVariable variable) {
      localVariables.Add(variable);
    }

    public void RemoveVariable(string name) {
      localVariables.Remove(GetLocalVariable(name));
    }

    public void AddSubTree(IFunctionTree tree) {
      subTrees.Add(tree);
    }

    public void InsertSubTree(int index, IFunctionTree tree) {
      subTrees.Insert(index, tree);
    }

    public void RemoveSubTree(int index) {
      subTrees.RemoveAt(index);
    }

    public double Evaluate(Dataset dataset, int sampleIndex) {
      return function.Evaluate(dataset, sampleIndex, subTrees);
    }
    #endregion

    public override XmlNode GetXmlNode(string name, System.Xml.XmlDocument document, IDictionary<Guid, IStorable> persistedObjects) {
      XmlNode node = base.GetXmlNode(name, document, persistedObjects);
      XmlNode subTreesNode = document.CreateNode(XmlNodeType.Element, "SubTrees", null);
      for(int i = 0; i < subTrees.Count; i++)
        subTreesNode.AppendChild(PersistenceManager.Persist(subTrees[i], document, persistedObjects));
      node.AppendChild(subTreesNode);
      XmlNode variablesNode = document.CreateNode(XmlNodeType.Element, "Variables", null);
      foreach(IVariable variable in localVariables)
        variablesNode.AppendChild(PersistenceManager.Persist(variable, document, persistedObjects));
      node.AppendChild(variablesNode);
      return node;
    }

    public override void Populate(XmlNode node, IDictionary<Guid, IStorable> restoredObjects) {
      base.Populate(node, restoredObjects);
      XmlNode subTreesNode = node.SelectSingleNode("SubTrees");
      for(int i = 0; i < subTreesNode.ChildNodes.Count; i++)
        AddSubTree((IFunctionTree)PersistenceManager.Restore(subTreesNode.ChildNodes[i], restoredObjects));
      XmlNode variablesNode = node.SelectSingleNode("Variables");
      foreach(XmlNode variableNode in variablesNode.ChildNodes)
        AddVariable((IVariable)PersistenceManager.Restore(variableNode, restoredObjects));
    }

    public override object Clone(IDictionary<Guid, object> clonedObjects) {
      FunctionTree clone = (FunctionTree)base.Clone(clonedObjects);
      foreach(IFunctionTree tree in subTrees) {
        clone.AddSubTree((IFunctionTree)tree.Clone(clonedObjects));
      }
      foreach(IVariable variable in localVariables) {
        clone.AddVariable((IVariable)variable.Clone(clonedObjects));
      }
      return clone;
    }

    public override IView CreateView() {
      return new FunctionTreeView(this);
    }
  }
}