using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Autodesk.Revit.DB;
using Room = Autodesk.Revit.DB.Architecture.Room;

namespace DisplayBoundary
{
  public static class PointInPolyExtensions
  {
    /// <summary>
    /// Add new point to list, unless already present.
    /// </summary>
    private static void AddToPunten(
      List<XYZ> XYZarray,
      XYZ p1 )
    {
      var p = XYZarray.Where(
        c => Math.Abs( c.X - p1.X ) < 0.001
          && Math.Abs( c.Y - p1.Y ) < 0.001 )
        .FirstOrDefault();

      if( p == null )
      {
        XYZarray.Add( p1 );
      }
    }

    /// <summary>
    /// Return a list of boundary 
    /// points for the given room.
    /// </summary>
    private static List<XYZ> MaakPuntArray(
      Room room )
    {
      SpatialElementBoundaryOptions opt
        = new SpatialElementBoundaryOptions();

      opt.SpatialElementBoundaryLocation
        = SpatialElementBoundaryLocation.Center;

      var boundaries = room.GetBoundarySegments(
        opt );

      return MaakPuntArray( boundaries );
    }

    /// <summary>
    /// Return a list of boundary points 
    /// for the given boundary segments.
    /// </summary>
    private static List<XYZ> MaakPuntArray(
      IList<IList<BoundarySegment>> boundaries )
    {
      List<XYZ> puntArray = new List<XYZ>();
      foreach( var bl in boundaries )
      {
        foreach( var s in bl )
        {
          Curve c = s.Curve;
          AddToPunten( puntArray, c.get_EndPoint( 0 ) );
          AddToPunten( puntArray, c.get_EndPoint( 1 ) );
        }
      }
      puntArray.Add( puntArray.First() );
      return puntArray;
    }

    /// <summary>
    /// Return a list of boundary 
    /// points for the given area.
    /// </summary>
    private static List<XYZ> MaakPuntArray(
      Area area )
    {
      SpatialElementBoundaryOptions opt
        = new SpatialElementBoundaryOptions();

      opt.SpatialElementBoundaryLocation
        = SpatialElementBoundaryLocation.Center;

      var boundaries = area.GetBoundarySegments(
        opt );

      return MaakPuntArray( boundaries );
    }

    /// <summary>
    /// Check whether this area contains a given point.
    /// </summary>
    public static bool AreaContains( this Area a, XYZ p1 )
    {
      bool ret = false;
      var p = MaakPuntArray( a );
      PointInPoly pp = new PointInPoly();
      ret = pp.PolyGonContains( p, p1 );
      return ret;
    }

    /// <summary>
    /// Check whether this room contains a given point.
    /// </summary>
    public static bool RoomContains( this Room r, XYZ p1 )
    {
      bool ret = false;
      var p = MaakPuntArray( r );
      PointInPoly pp = new PointInPoly();
      ret = pp.PolyGonContains( p, p1 );
      return ret;
    }

    /// <summary>
    /// Project an XYZ point to a UV one in the 
    /// XY plane by simply dropping the Z coordinate.
    /// </summary>
    public static UV TOUV( this XYZ point )
    {
      UV ret = new UV( point.X, point.Y );
      return ret;
    }
  }
}