// Copyright 2010 ESRI
// 
// All rights reserved under the copyright laws of the United States
// and applicable international laws, treaties, and conventions.
// 
// You may freely redistribute and use this sample code, with or
// without modification, provided you include the original copyright
// notice and use restrictions.
// 
// See the use restrictions.
// 

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Geodatabase;

namespace SubsetNetworkEvaluators
{
  /// <summary>
  /// The scale subset network evaluator is a custom network evaluator for modeling slowdown polygons
  /// where traffic speeds are slowed down in only a particular subset of the network.  In this
  /// example the subset of network elements that are slowed down is determined based on the geometry
  /// of graphic elements drawn in arc map, but it does not matter how the element subset is determined.
  /// The elements that are not in the subset just return the non-scaled base attribute value.  This could
  /// be useful, for example, if certain low lying areas had a flash flood, or other localized congestion that
  /// does not affect the network as a whole.  The subset of elements to be scaled and the scale factor to
  /// scale the base attribute by in the scale subset evaluator are network attribute parameters of the attribute
  /// the evaluator is assigned to.
  /// </summary>

  [ClassInterface(ClassInterfaceType.None)]
  [Guid("67cf8446-22a2-4baf-9c97-3c22a33cc0c7")]
  [ProgId("SubsetNetworkEvaluators.ScaleSubsetEvaluator")]
  public class ScaleSubsetEvaluator : INetworkEvaluator2, INetworkEvaluatorSetup
  {
    #region Member Variables

    private INetworkDataset m_networkDataset;
    private INetworkSource m_networkSource;
    private INetworkAttribute m_networkAttribute;

    private double m_scaleFactor = 1;
    private int m_thisNetworkAttributeID = -1;  // the ID for this attribute
    private int m_baseNetworkAttributeID = -1;  // the ID for the other attribute that should be scale (determined based on attribute name)
    private int m_countSourceEIDs = 0;          // number of EIDs to override for this source 
    private Dictionary<int, int> m_sourceEIDHashTable;           // the EIDs to override values for, by scaling, for this source

    #endregion

    #region INetworkEvaluator Members

    public bool CacheAttribute
    {
      // CacheAttribute returns whether or not we want the network dataset to cache our evaluated attribute values during the network dataset build
      // Since this is a dynamic evaluator, we will return false, so that our attribute values are dynamically queried at runtime
      get { return false; }
    }

    public string DisplayName
    {
      get { return "ScaleSubset"; }
    }

    public string Name
    {
      get { return "SubsetNetworkEvaluators.ScaleSubset"; }
    }

    #endregion

    #region INetworkEvaluator2 Members

    public void Refresh()
    {
      // This method is called internally during a solve operation immediately prior to performing the actual solve
      // This gives us an opportunity to update our evaluator's internal state based on parameter values

      m_scaleFactor = 1;
      m_countSourceEIDs = 0;
      m_sourceEIDHashTable = new Dictionary<int, int>();

      INetworkAttribute2 netAttribute2 = m_networkAttribute as INetworkAttribute2;
      IArray netAttributeParams = netAttribute2.Parameters;

      // Parameters: "ScaleSubset_Factor", "ScaleSubset_eids_<SourceName>"
      string prefix = BaseParameterName + "_";

      string paramScaleFactorName = prefix + "Factor";
      string paramEIDsName = prefix + "eids_" + m_networkSource.Name;

      int nParamScaleFactor = SubsetHelper.FindParameter(netAttributeParams, paramScaleFactorName);
      int nParamEIDs = SubsetHelper.FindParameter(netAttributeParams, paramEIDsName);

      object value;

      INetworkAttributeParameter paramScaleFactor;
      INetworkAttributeParameter paramEIDs;

      if (nParamScaleFactor >= 0)
      {
        paramScaleFactor = netAttributeParams.get_Element(nParamScaleFactor) as INetworkAttributeParameter;
        value = paramScaleFactor.Value;
        if (value != null)
          m_scaleFactor = (double)value;
      }

      if (nParamEIDs >= 0)
      {
        paramEIDs = netAttributeParams.get_Element(nParamEIDs) as INetworkAttributeParameter;
        value = paramEIDs.Value as int[];
        if (value != null)
        {
          int eid;
          int[] rgEIDs;
          rgEIDs = (int[])value;

          int lb = rgEIDs.GetLowerBound(0);
          int ub = rgEIDs.GetUpperBound(0);

          for (int i = lb; i <= ub; ++i)
          {
            ++m_countSourceEIDs;
            eid = rgEIDs[i];
            m_sourceEIDHashTable.Add(eid, eid);
          }
        }
      }
    }

    public IStringArray RequiredFieldNames
    {
      // This custom evaluator does not require any field names
      get { return null; }
    }

    #endregion

    #region INetworkEvaluatorSetup Members

    public UID CLSID
    {
      get
      {
        // Create and return the GUID for this custom evaluator
        UID uid = new UIDClass();
        uid.Value = "{67cf8446-22a2-4baf-9c97-3c22a33cc0c7}";
        return uid;
      }
    }

    public IPropertySet Data
    {
      // The Data property is intended to make use of property sets to get/set the custom evaluator's properties using only one call to the evaluator object
      // This custom evaluator does not make use of this property
      get { return null; }
      set { }
    }

    public bool DataHasEdits
    {
      // Since this custom evaluator does not make any data edits, return false
      get { return false; }
    }

    public void Initialize(INetworkDataset networkDataset, IDENetworkDataset DataElement, INetworkSource netSource, IEvaluatedNetworkAttribute netAttribute)
    {
      // Initialize is called once per session (ArcMap session, ArcCatalog session, etc.) to initialize the evaluator for an associated network dataset            
      m_networkDataset = networkDataset;
      m_networkSource = netSource;
      m_networkAttribute = netAttribute;

      m_thisNetworkAttributeID = netAttribute.ID;
      m_baseNetworkAttributeID = -1;

      //The attribute name must begin with one or more non underscore characters followed by
      //an underscore character and then the name of the base cost attribute.
      //The underscore prior to the base attribute name should be the first underscore in the name.

      string thisAttributeName = netAttribute.Name;
      int nPos = thisAttributeName.IndexOf('_');
      int nLastPos = thisAttributeName.Length - 1;

      string baseNetAttributeName;
      INetworkAttribute baseNetAttribute = null;

      if (nPos > 0 && nPos < nLastPos)
      {
        baseNetAttributeName = thisAttributeName.Remove(0, nPos + 1);
        try
        {
          baseNetAttribute = networkDataset.get_AttributeByName(baseNetAttributeName);
        }
        catch (COMException ex)
        {
          baseNetAttribute = null;
          string msg = string.Format("Base Attribute ({0}) not found. {1}.", baseNetAttributeName, ex.Message);
          System.Diagnostics.Trace.WriteLine(msg, "Scale Subset Network Evaluator");
        }

        if (baseNetAttribute != null)
        {
          if (baseNetAttribute.ID != m_thisNetworkAttributeID)
            m_baseNetworkAttributeID = baseNetAttribute.ID;
        }
      }

      Refresh();
    }

    public object QueryValue(INetworkElement Element, IRow Row)
    {
      if (m_baseNetworkAttributeID < 0)
        return -1;

      object value = Element.get_AttributeValue(m_baseNetworkAttributeID);
      if (value == null)
        return -1;

      double baseValue = (double)value;
      if (baseValue <= 0 || m_scaleFactor == 1 || m_countSourceEIDs <= 0)
        return baseValue;

      bool isScaled = false;

      int eid = -1;
      if (m_sourceEIDHashTable.TryGetValue(Element.EID, out eid))
        isScaled = (eid > 0);

      object resultValue = baseValue;
      if (isScaled)
      {
        if (m_scaleFactor >= 0)
          resultValue = m_scaleFactor * baseValue;
        else
          resultValue = -1;
      }

      return resultValue;
    }

    public object QueryPartialEdgeValue(INetworkEdge2 edge, double fromPos, double toPos)
    {
      // Partial Edge values are not appropriate for restriction evaluators.
      throw new NotImplementedException();
    }

    public bool SupportsDefault(esriNetworkElementType ElementType, IEvaluatedNetworkAttribute netAttribute)
    {
      return false;
    }

    public bool SupportsSource(INetworkSource netSource, IEvaluatedNetworkAttribute netAttribute)
    {
      // This custom evaluator supports cost attributes for all sources
      return netAttribute.UsageType == esriNetworkAttributeUsageType.esriNAUTCost;
    }

    public bool ValidateDefault(esriNetworkElementType ElementType, IEvaluatedNetworkAttribute netAttribute, ref int ErrorCode, ref string ErrorDescription, ref string errorAppendInfo)
    {
      if (SupportsDefault(ElementType, netAttribute))
      {
        ErrorCode = 0;
        ErrorDescription = errorAppendInfo = string.Empty;
        return true;
      }
      else
      {
        ErrorCode = -1;
        ErrorDescription = errorAppendInfo = string.Empty;
        return false;
      }
    }

    public bool ValidateSource(IDatasetContainer2 datasetContainer, INetworkSource netSource, IEvaluatedNetworkAttribute netAttribute, ref int ErrorCode, ref string ErrorDescription, ref string errorAppendInfo)
    {
      if (SupportsSource(netSource, netAttribute))
      {
        ErrorCode = 0;
        ErrorDescription = errorAppendInfo = string.Empty;
        return true;
      }
      else
      {
        ErrorCode = -1;
        ErrorDescription = errorAppendInfo = string.Empty;
        return false;
      }
    }

    #endregion

    #region Static Members

    public static string BaseParameterName
    {
      get
      {
        return "ScaleSubset";
      }
    }

    public static void RemoveScaleSubsetAttributes(IDENetworkDataset deNet)
    {
      IArray netAttributes = SubsetHelper.RemoveAttributesByPrefix(deNet.Attributes, BaseParameterName);
      deNet.Attributes = netAttributes;
    }

    public static List<IEvaluatedNetworkAttribute> AddScaleSubsetAttributes(IDENetworkDataset deNet)
    {
      List<IEvaluatedNetworkAttribute> scaleSubsetAttributes = new List<IEvaluatedNetworkAttribute>();

      IArray netAttributesArray = deNet.Attributes;
      List<int> baseIndexes = SubsetHelper.FindAttributeIndexes(netAttributesArray, esriNetworkAttributeUsageType.esriNAUTCost, esriNetworkAttributeDataType.esriNADTDouble, true, false);
      List<INetworkAttribute2> baseNetAttributes = SubsetHelper.FindAttributes(netAttributesArray, baseIndexes);
      foreach (INetworkAttribute2 baseNetAttribute in baseNetAttributes)
        scaleSubsetAttributes.Add(AddScaleSubsetAttribute(deNet, baseNetAttribute));

      return scaleSubsetAttributes;
    }

    public static IEvaluatedNetworkAttribute AddScaleSubsetAttribute(IDENetworkDataset deNet, INetworkAttribute2 baseNetAttribute)
    {
      if (baseNetAttribute == null)
        return null;

      if (baseNetAttribute.UsageType != esriNetworkAttributeUsageType.esriNAUTCost)
        return null;

      IArray netAttributes = deNet.Attributes;
      IEvaluatedNetworkAttribute netAttribute = new EvaluatedNetworkAttributeClass() as IEvaluatedNetworkAttribute;

      string netAttributeName = BaseParameterName;
      netAttributeName += "_";
      netAttributeName += baseNetAttribute.Name;

      netAttribute.Name = netAttributeName;
      netAttribute.UsageType = baseNetAttribute.UsageType;
      netAttribute.DataType = baseNetAttribute.DataType;
      netAttribute.Units = baseNetAttribute.Units;

      List<INetworkSource> allNetSources = SubsetHelper.GetSourceList(deNet.Sources);
      List<INetworkSource> netSources = SubsetHelper.GetSourceList(allNetSources, esriNetworkElementType.esriNETEdge);
      List<string> netSourceNames = SubsetHelper.GetSourceNames(netSources);

      ResetScaleSubsetParameters((INetworkAttribute2)netAttribute, netSourceNames);

      bool supportTurns = deNet.SupportsTurns;

      //default evaluators
      SubsetHelper.SetDefaultEvaluator(netAttribute, 0, esriNetworkElementType.esriNETEdge);
      SubsetHelper.SetDefaultEvaluator(netAttribute, 0, esriNetworkElementType.esriNETJunction);
      if (supportTurns)
        SubsetHelper.SetDefaultEvaluator(netAttribute, 0, esriNetworkElementType.esriNETTurn);

      //sourced evaluators
      foreach (INetworkSource netSource in netSources)
        SubsetHelper.SetEvaluators(netAttribute, netSource, typeof(ScaleSubsetEvaluator));

      netAttributes.Add(netAttribute);
      deNet.Attributes = netAttributes;

      return netAttribute;
    }

    public static void ResetScaleSubsetParameters(INetworkAttribute2 netAttribute, List<string> netSourceNames)
    {
      IArray netParams = new ESRI.ArcGIS.esriSystem.ArrayClass();
      INetworkAttributeParameter netParam = null;
      object paramValue = null;
      string paramName = "";

      netParam = new NetworkAttributeParameterClass();
      paramValue = 1;

      paramName = BaseParameterName;
      paramName += "_Factor";

      netParam.Name = paramName;
      netParam.VarType = (int)VarType.Double;
      netParam.Value = paramValue;
      netParam.DefaultValue = paramValue;
      netParams.Add(netParam);

      foreach (string netSourceName in netSourceNames)
      {
        netParam = new NetworkAttributeParameterClass();
        paramValue = null;

        paramName = BaseParameterName;
        paramName += "_eids_";
        paramName += netSourceName;
        netParam.Name = paramName;
        netParam.VarType = (int)(VarType.Array | VarType.Integer);
        netParam.Value = paramValue;
        netParam.DefaultValue = paramValue;
        netParams.Add(netParam);
      }

      //does not preserve existing parameters if any
      netAttribute.Parameters = netParams;
    }

    #endregion
  }
}