///
///    This file is part of ILNumerics Community Edition.
///
///    ILNumerics Community Edition - high performance computing for applications.
///    Copyright (C) 2006 - 2012 Haymo Kutschbach, http://ilnumerics.net
///
///    ILNumerics Community Edition is free software: you can redistribute it and/or modify
///    it under the terms of the GNU General Public License version 3 as published by
///    the Free Software Foundation.
///
///    ILNumerics Community Edition is distributed in the hope that it will be useful,
///    but WITHOUT ANY WARRANTY; without even the implied warranty of
///    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
///    GNU General Public License for more details.
///
///    You should have received a copy of the GNU General Public License
///    along with ILNumerics Community Edition. See the file License.txt in the root
///    of your distribution package. If not, see <http://www.gnu.org/licenses/>.
///
///    In addition this software uses the following components and/or licenses: 
///
///    =================================================================================
///    The Open Toolkit Library License
///    
///    Copyright (c) 2006 - 2009 the Open Toolkit library.
///    
///    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 and this permission notice shall be included in all
///    copies or substantial portions of the Software.
///
///    =================================================================================
///    

using System;
using System.Collections.Generic;
using System.Text;
using ILNumerics.Drawing; 
using ILNumerics.Drawing.Shapes;

namespace ILNumerics.Drawing.Graphs {
    /// <summary>
    /// scene graph inner node, collection of children
    /// </summary>
    public class ILSceneGraphInnerNode : ILSceneGraphNode, ICollection<ILSceneGraphNode>,
            IList<ILSceneGraphNode> {

        #region attributes
        private List<ILSceneGraphNode> m_childs;
        private ILArray<float> m_centers;
        #endregion

        #region constructors
        public ILSceneGraphInnerNode(ILPanel panel) 
        :base (panel) {

            m_centers = ILMath.returnType<float>();
            m_childs = new List<ILSceneGraphNode>(); 

        }

        #endregion

        #region public interface
        /// <summary>
        /// recompute the size spanned by this node, may fires Changed() event
        /// </summary>
        internal override void Configure() {
            if (m_invalidated) {
                // configure childs (compute limits) first
                foreach (ILSceneGraphNode child in m_childs) {
                    child.Configure();
                }
                bool sizechanged = false;
                ILPoint3Df oldMin = m_positionMin;
                ILPoint3Df oldMax = m_positionMax;
                ComputeNodeLimits();
                if (oldMin != m_positionMin) sizechanged = true;
                if (oldMax != m_positionMax) sizechanged = true;
                m_invalidated = false;
                if (sizechanged)
                    OnSizeChanged();
            }
        }
        internal override void Draw(ILRenderProperties props) {
            if (!m_visible) {
                return;
            }
            if (m_childs != null && m_childs.Count > 0) {
                ILArray<int> indices = Computation.GetSortedIndices(
                                     m_centers, m_panel.Camera.Position);
                foreach (int i in indices) {
                    if (m_childs[i].Visible)
                        m_childs[i].Draw(props);
                }
            }
        }
        public override void Invalidate() {
            base.Invalidate();
            m_centers.a = ILMath.empty<float>(ILSize.Empty00); 
        }
        /// <summary>
        /// compute limits of the cube tightly enclosing the branch below this node
        /// </summary>
        /// <returns></returns>
        protected override void ComputeNodeLimits() {
            if (m_childs == null || m_childs.Count == 0) {
                m_positionMin = ILPoint3Df.Empty;
                m_positionMax = ILPoint3Df.Empty;
                return; 
            }
            // acquire maximum position
            ILPoint3Df curMax = ILPoint3Df.MinValue;
            ILPoint3Df curMin = ILPoint3Df.MaxValue;
            foreach (ILSceneGraphNode node in m_childs) {
                curMin = ILPoint3Df.Min(node.PositionMin, curMin);
            }
            curMax = ILPoint3Df.MinValue;
            foreach (ILSceneGraphNode node in m_childs) {
                curMax = ILPoint3Df.Max(node.PositionMax, curMax);
            }
            m_positionMax = curMax;
            m_positionMin = curMin;
            m_center = (m_positionMax + m_positionMin) / 2;
            // stores childs centers for sorting
            if (m_centers.IsEmpty)
                m_centers.a = ILMath.zeros<float>(m_childs.Count, 3);
            for (int i = m_childs.Count; i-- > 0; ) {
                ILPoint3Df center = m_childs[i].Center;
                m_centers.SetValue(center.X, i, 0);
                m_centers.SetValue(center.Y, i, 1);
                m_centers.SetValue(center.Z, i, 2);
            }
        }
        internal override void CollectAllChildren(List<ILSceneGraphNode> nodes) {
            nodes.Add(this); //    base.CollectAllChildren(nodes); // add self
            if (m_childs != null) {
                foreach (ILSceneGraphNode child in m_childs) {
                    child.CollectAllChildren(nodes);
                }
            }
        }
        public virtual void Add(ILShape shape) {
            ILSceneGraphShapedLeaf node = new ILSceneGraphShapedLeaf(m_panel);
            node.Parent = this; 
            node.Shape = shape;
            m_childs.Add(node);
            Invalidate(); 
            OnNodeAdded(node); 
        }
        public virtual void Remove(ILShape shape) {
            ILSceneGraphNode node = null; 
            foreach (ILSceneGraphNode n in m_childs) {
                if (n is ILSceneGraphShapedLeaf) { 
                    if (object.Equals((n as ILSceneGraphShapedLeaf).Shape,shape)) {
                        node = n; 
                        break; 
                    }
                }
            }
            if (node != null) {
                m_childs.Remove(node); 
                OnNodeRemoved(node); 
            }
        }      
        #endregion

        #region IList<ILSceneGraphNode> Member

        public virtual ILSceneGraphNode this[int i] {
            get {
                return m_childs[i];
            }
            set {
                m_childs[i] = value;
                Invalidate(); 
            }
        }

        public virtual int IndexOf(ILSceneGraphNode item) {
            return m_childs.IndexOf(item);
        }

        public virtual void Insert(int index, ILSceneGraphNode item) {
            m_childs.Insert(index, item);
            Invalidate(); 
        }

        public virtual void RemoveAt(int index) {
            m_childs.RemoveAt(index);
            Invalidate(); 
        }
        #endregion

        #region ICollection<ILSceneGraphNode> Member
        /// <summary>
        /// add a single node to the end of child collection
        /// </summary>
        /// <param name="item">node to add </param>
        public virtual void Add(ILSceneGraphNode item) {
            m_childs.Add(item);
            item.Parent = this;
            item.Invalidate();
            OnNodeAdded(item);
        }
        /// <summary>
        /// wipe all nodes from the collection 
        /// </summary>
        public virtual void Clear() {
            m_childs.Clear();
            Invalidate(); 
        }
        /// <summary>
        /// Determine, if this collection contains a specific node item
        /// </summary>
        /// <param name="item"></param>
        /// <returns></returns>
        public bool Contains(ILSceneGraphNode item) {
            return m_childs.Contains(item);
        }

        public void CopyTo(ILSceneGraphNode[] array, int arrayIndex) {
            m_childs.CopyTo(array, arrayIndex);
        }
        /// <summary>
        /// Number of children contained in this node
        /// </summary>
        public virtual int Count {
            get { return m_childs.Count; }
        }
        /// <summary>
        /// determine if this collection is readonly, (returns 'false')
        /// </summary>
        public bool IsReadOnly {
            get { return false; }
        }
        /// <summary>
        /// remove a single child node from the collection
        /// </summary>
        /// <param name="item">node to be removed</param>
        /// <returns>true</returns>
        public virtual bool Remove(ILSceneGraphNode item) {
            m_childs.Remove(item);
            Invalidate();
            return true; 
        }

        #endregion

        #region private helpers

        private class Computation : ILNumerics.ILMath {
            /// <summary>
            /// compute distance to camera and return sorted indices for rendering
            /// </summary>
            /// <param name="centers">current primitive centers</param>
            /// <param name="position">current camera position</param>
            /// <returns>sorted indices of primitives in descending order</returns>
            internal static ILRetArray<int> GetSortedIndices(ILInArray<float> centers, ILPoint3Df position) {
                using (ILScope.Enter(centers)) {
                    ILArray<float> pos = array<float>(size(1,3), -position.X, -position.Y, -position.Z);
                    // move camera outside of centers
                    pos.a *= maxall(abs(centers));
                    //pos.a = repmat(pos, centers.Dimensions[0], 1);
                    // compute distances
                    ILArray<float> dist = sum(pow(centers - pos, 2), 1);
                    ILArray<double> ret = empty();
                    sort(dist, ret, 0, false);
                    return toint32(ret);
                }
            }
        }

        #endregion

    }
}