/* Poly2Tri
 * Copyright (c) 2009-2010, Poly2Tri Contributors
 * http://code.google.com/p/poly2tri/
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * * Neither the name of Poly2Tri nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without specific
 *   prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/// Changes from the Java version
///   Polygon constructors sprused up, checks for 3+ polys
///   Naming of everything
///   getTriangulationMode() -> TriangulationMode { get; }
///   Exceptions replaced
/// Future possibilities
///   We have a lot of Add/Clear methods -- we may prefer to just expose the container
///   Some self-explanatory methods may deserve commenting anyways

using System;
using System.Collections.Generic;
using System.Linq;


namespace Poly2Tri
{
    public class Polygon : Point2DList, ITriangulatable, IEnumerable<TriangulationPoint>, IList<TriangulationPoint>
    {
        // ITriangulatable Implementation
        protected Dictionary<uint, TriangulationPoint> mPointMap = new Dictionary<uint, TriangulationPoint>();
        public IList<TriangulationPoint> Points { get { return this; } }
        protected List<DelaunayTriangle> mTriangles;
        public IList<DelaunayTriangle> Triangles { get { return mTriangles; } }
        public TriangulationMode TriangulationMode { get { return TriangulationMode.Polygon; } }
        public string FileName { get; set; }
        public bool DisplayFlipX { get; set; }
        public bool DisplayFlipY { get; set; }
        public float DisplayRotate { get; set; }
        private double mPrecision = TriangulationPoint.kVertexCodeDefaultPrecision;
        public double Precision { get { return mPrecision; } set { mPrecision = value; } }
        public double MinX { get { return mBoundingBox.MinX; } }
        public double MaxX { get { return mBoundingBox.MaxX; } }
        public double MinY { get { return mBoundingBox.MinY; } }
        public double MaxY { get { return mBoundingBox.MaxY; } }
        public Rect2D Bounds { get { return mBoundingBox; } }

        // Point2DList overrides
        public new TriangulationPoint this[int index]
        {
            get { return mPoints[index] as TriangulationPoint; }
            set { mPoints[index] = value; }
        }

        // Polygon Implementation
        protected List<Polygon> mHoles;
        public IList<Polygon> Holes { get { return mHoles; } }
        protected List<TriangulationPoint> mSteinerPoints;
        protected PolygonPoint _last;



        /// <summary>
        /// Create a polygon from a list of at least 3 points with no duplicates.
        /// </summary>
        /// <param name="points">A list of unique points</param>
        public Polygon(IList<PolygonPoint> points)
        {
            if (points.Count < 3)
            {
                throw new ArgumentException("List has fewer than 3 points", "points");
            }

            AddRange(points, WindingOrderType.Unknown);
        }


        /// <summary>
        /// Create a polygon from a list of at least 3 points with no duplicates.
        /// </summary>
        /// <param name="points">A list of unique points.</param>
        public Polygon(IEnumerable<PolygonPoint> points) 
            : this((points as IList<PolygonPoint>) ?? points.ToArray()) 
        {}


        /// <summary>
        /// Create a polygon from a list of at least 3 points with no duplicates.
        /// </summary>
        /// <param name="points">A list of unique points.</param>
        public Polygon(params PolygonPoint[] points)
            : this((IList<PolygonPoint>)points)
        {}


        IEnumerator<TriangulationPoint> IEnumerable<TriangulationPoint>.GetEnumerator()
        {
            return new TriangulationPointEnumerator(mPoints);
        }


        public int IndexOf(TriangulationPoint p)
        {
            return mPoints.IndexOf(p);
        }


        public override void Add(Point2D p)
        {
            Add(p, -1, true);
        }


        public void Add(TriangulationPoint p)
        {
            Add(p, -1, true);
        }


        public void Add(PolygonPoint p)
        {
            Add(p, -1, true);
        }


        protected override void Add(Point2D p, int idx, bool bCalcWindingOrderAndEpsilon)
        {
            TriangulationPoint pt = p as TriangulationPoint;
            if (pt == null)
            {
                // we only store TriangulationPoints and PolygonPoints in this class
                return;
            }

            // do not insert duplicate points
            if (mPointMap.ContainsKey(pt.VertexCode))
            {
                return;
            }
            mPointMap.Add(pt.VertexCode, pt);

            base.Add(p, idx, bCalcWindingOrderAndEpsilon);

            PolygonPoint pp = p as PolygonPoint;
            if (pp != null)
            {
                pp.Previous = _last;
                if (_last != null)
                {
                    pp.Next = _last.Next;
                    _last.Next = pp;
                }
                _last = pp;
            }

            return;
        }


        public void AddRange(IList<PolygonPoint> points, Point2DList.WindingOrderType windingOrder)
        {
            if (points == null || points.Count < 1)
            {
                return;
            }

            if (mWindingOrder == Point2DList.WindingOrderType.Unknown && Count == 0)
            {
                mWindingOrder = windingOrder;
            }
            int numPoints = points.Count;
            bool bReverseReadOrder = (WindingOrder != WindingOrderType.Unknown) && (windingOrder != WindingOrderType.Unknown) && (WindingOrder != windingOrder);
            for (int i = 0; i < numPoints; ++i)
            {
                int idx = i;
                if (bReverseReadOrder)
                {
                    idx = points.Count - i - 1;
                }
                Add(points[idx], -1, false);
            }
            if (mWindingOrder == WindingOrderType.Unknown)
            {
                mWindingOrder = CalculateWindingOrder();
            }
            mEpsilon = CalculateEpsilon();
        }


        public void AddRange(IList<TriangulationPoint> points, Point2DList.WindingOrderType windingOrder)
        {
            if (points == null || points.Count < 1)
            {
                return;
            }

            if (mWindingOrder == Point2DList.WindingOrderType.Unknown && Count == 0)
            {
                mWindingOrder = windingOrder;
            }

            int numPoints = points.Count;
            bool bReverseReadOrder = (WindingOrder != WindingOrderType.Unknown) && (windingOrder != WindingOrderType.Unknown) && (WindingOrder != windingOrder);
            for (int i = 0; i < numPoints; ++i)
            {
                int idx = i;
                if (bReverseReadOrder)
                {
                    idx = points.Count - i - 1;
                }
                Add(points[idx], -1, false);
            }
            if (mWindingOrder == WindingOrderType.Unknown)
            {
                mWindingOrder = CalculateWindingOrder();
            }
            mEpsilon = CalculateEpsilon();
        }


        public void Insert(int idx, TriangulationPoint p)
        {
            Add(p, idx, true);
        }


        public bool Remove(TriangulationPoint p)
        {
            return base.Remove(p);
        }


        /// <summary>
        /// Removes a point from the polygon.  Note this can be a somewhat expensive operation
        /// as it must recalculate the bounding area from scratch.
        /// </summary>
        /// <param name="p"></param>
        public void RemovePoint(PolygonPoint p)
        {
            PolygonPoint next, prev;

            next = p.Next;
            prev = p.Previous;
            prev.Next = next;
            next.Previous = prev;
            mPoints.Remove(p);

            mBoundingBox.Clear();
            foreach (PolygonPoint tmp in mPoints)
            {
                mBoundingBox.AddPoint(tmp);
            }
        }



        public bool Contains(TriangulationPoint p)
        {
            return mPoints.Contains(p);
        }


        public void CopyTo(TriangulationPoint[] array, int arrayIndex)
        {
            int numElementsToCopy = Math.Min(Count, array.Length - arrayIndex);
            for (int i = 0; i < numElementsToCopy; ++i)
            {
                array[arrayIndex + i] = mPoints[i] as TriangulationPoint;
            }
        }


        public void AddSteinerPoint(TriangulationPoint point)
        {
            if (mSteinerPoints == null)
            {
                mSteinerPoints = new List<TriangulationPoint>();
            }
            mSteinerPoints.Add(point);
        }


        public void AddSteinerPoints(List<TriangulationPoint> points)
        {
            if (mSteinerPoints == null)
            {
                mSteinerPoints = new List<TriangulationPoint>();
            }
            mSteinerPoints.AddRange(points);
        }


        public void ClearSteinerPoints()
        {
            if (mSteinerPoints != null)
            {
                mSteinerPoints.Clear();
            }
        }


        /// <summary>
        /// Add a hole to the polygon.
        /// </summary>
        /// <param name="poly">A subtraction polygon fully contained inside this polygon.</param>
        public void AddHole(Polygon poly)
        {
            if (mHoles == null)
            {
                mHoles = new List<Polygon>();
            }
            mHoles.Add(poly);
            // XXX: tests could be made here to be sure it is fully inside
            //        addSubtraction( poly.getPoints() );
        }


        public void AddTriangle(DelaunayTriangle t)
        {
            mTriangles.Add(t);
        }


        public void AddTriangles(IEnumerable<DelaunayTriangle> list)
        {
            mTriangles.AddRange(list);
        }

        
        public void ClearTriangles()
        {
            if (mTriangles != null)
            {
                mTriangles.Clear();
            }
        }


        public bool IsPointInside(TriangulationPoint p)
        {
            return PolygonUtil.PointInPolygon2D(this, p);
        }


        /// <summary>
        /// Creates constraints and populates the context with points
        /// </summary>
        /// <param name="tcx">The context</param>
        public void Prepare(TriangulationContext tcx)
        {
            if (mTriangles == null)
            {
                mTriangles = new List<DelaunayTriangle>(mPoints.Count);
            }
            else
            {
                mTriangles.Clear();
            }

            // Outer constraints
            for (int i = 0; i < mPoints.Count - 1; i++)
            {
                //tcx.NewConstraint(mPoints[i], mPoints[i + 1]);
                tcx.NewConstraint(this[i], this[i + 1]);
            }
            tcx.NewConstraint(this[0], this[Count - 1]);
            tcx.Points.AddRange(this);

            // Hole constraints
            if (mHoles != null)
            {
                foreach (Polygon p in mHoles)
                {
                    for (int i = 0; i < p.mPoints.Count - 1; i++)
                    {
                        tcx.NewConstraint(p[i], p[i + 1]);
                    }
                    tcx.NewConstraint(p[0], p[p.Count - 1]);
                    tcx.Points.AddRange(p);
                }
            }

            if (mSteinerPoints != null)
            {
                tcx.Points.AddRange(mSteinerPoints);
            }
        }
    }
}