/*
** SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
** Copyright (C) 2011 Silicon Graphics, Inc.
** All Rights Reserved.
**
** Permission is hereby granted, free of charge, to any person obtaining a copy
** of this software and associated documentation files (the "Software"), to deal
** in the Software without restriction, including without limitation the rights
** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
** of the Software, and to permit persons to whom the Software is furnished to do so,
** subject to the following conditions:
**
** The above copyright notice including the dates of first publication and either this
** permission notice or a reference to http://oss.sgi.com/projects/FreeB/ shall be
** included in all copies or substantial portions of the Software.
**
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
** INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
** PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL SILICON GRAPHICS, INC.
** BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
** OR OTHER DEALINGS IN THE SOFTWARE.
**
** Except as contained in this notice, the name of Silicon Graphics, Inc. shall not
** be used in advertising or otherwise to promote the sale, use or other dealings in
** this Software without prior written authorization from Silicon Graphics, Inc.
*/
/*
** Original Author: Eric Veach, July 1994.
** libtess2: Mikko Mononen, http://code.google.com/p/libtess2/.
** LibTessDotNet: Remi Gillig, https://github.com/speps/LibTessDotNet
*/

using UnityEngine.Scripting.APIUpdating;

namespace UnityEngine.Rendering.Universal
{
    namespace LibTessDotNet
    {
        internal class Dict<TValue> where TValue : class
        {
            public class Node
            {
                internal TValue _key;
                internal Node _prev, _next;

                public TValue Key { get { return _key; } }
                public Node Prev { get { return _prev; } }
                public Node Next { get { return _next; } }
            }

            public delegate bool LessOrEqual(TValue lhs, TValue rhs);

            private LessOrEqual _leq;
            Node _head;

            public Dict(LessOrEqual leq)
            {
                _leq = leq;

                _head = new Node { _key = null };
                _head._prev = _head;
                _head._next = _head;
            }

            public Node Insert(TValue key)
            {
                return InsertBefore(_head, key);
            }

            public Node InsertBefore(Node node, TValue key)
            {
                do
                {
                    node = node._prev;
                }
                while (node._key != null && !_leq(node._key, key));

                var newNode = new Node { _key = key };
                newNode._next = node._next;
                node._next._prev = newNode;
                newNode._prev = node;
                node._next = newNode;

                return newNode;
            }

            public Node Find(TValue key)
            {
                var node = _head;
                do
                {
                    node = node._next;
                }
                while (node._key != null && !_leq(key, node._key));
                return node;
            }

            public Node Min()
            {
                return _head._next;
            }

            public void Remove(Node node)
            {
                node._next._prev = node._prev;
                node._prev._next = node._next;
            }
        }
    }
}