using System;
using System.Collections.Generic;
using System.Text;

using CommonAI.RTS;
using CommonLang.Vector;
using CommonLang;
using CommonLang.Concurrent;

namespace CommonAI.RTS.Manhattan
{
	partial class AstarManhattan
	{
		//---------------------------------------------------------------------------------------------------------------------
		internal class MTerrain : ITerrain<MMapNode>
		{
			internal readonly IManhattanMap map_data;
			internal readonly AstarManhattan manhattan;
			internal readonly bool is_inclined;
			internal readonly int xcount;
			internal readonly int ycount;

			private int nodes_count;
			private MMapNode[,] all_nodes_map;

			public int TotalNodeCount
			{
				get { return nodes_count; }
			}

			internal MTerrain(AstarManhattan manhattan, IManhattanMap map, bool inclined)
			{
				this.manhattan = manhattan;
				this.map_data = map;
				this.is_inclined = inclined;
				this.xcount = map.XCount;
				this.ycount = map.YCount;
				this.nodes_count = 0;

				this.all_nodes_map = new MMapNode[xcount, ycount];
				for (int y = 0; y < ycount; y++)
				{
					for (int x = 0; x < xcount; x++)
					{
						if (map.TestBlock(x, y) == false)
						{
							all_nodes_map[x, y] = map.CreateMapNode();
							nodes_count++;
						}
					}
				}
				for (int y = 0; y < ycount; y++)
				{
					for (int x = 0; x < xcount; x++)
					{
						MMapNode node = all_nodes_map[x, y];
						if (node != null)
						{
							node.Init(this, x, y);
						}
					}
				}
				for (int y = 0; y < ycount; y++)
				{
					for (int x = 0; x < xcount; x++)
					{
						MMapNode node = all_nodes_map[x, y];
						if (node != null)
						{
							node.resetNextNodes(this);
						}
					}
				}
			}
			public void Dispose()
			{
				for (int y = 0; y < ycount; y++)
				{
					for (int x = 0; x < xcount; x++)
					{
						MMapNode node = all_nodes_map[x, y];
						if (node != null)
						{
							node.Dispose();
						}
					}
				}
				this.map_data.Dispose();
				this.all_nodes_map = null;
			}
			public void ForEachNodes(Action<MMapNode> action)
			{
				for (int y = 0; y < ycount; y++)
				{
					for (int x = 0; x < xcount; x++)
					{
						MMapNode node = all_nodes_map[x, y];
						if (node != null)
						{
							action(node);
						}
					}
				}
			}

			public MMapNode getMapNode(int bx, int by)
			{
				return all_nodes_map[bx, by];
			}

			public bool touchMapBlock(int bx, int by)
			{
				if (bx < 0 || bx >= xcount)
					return true;
				if (by < 0 || by >= ycount)
					return true;
				var node = all_nodes_map[bx, by];
				if (node != null)
				{
					return node.Blocked;
				}
				return true;
			}
		}

		public class MMapNode : MapNode
		{
			/// <summary>
			/// 实例数量
			/// </summary>
			public static int ActiveObjectCount { get { return s_active_object_count.Value; } }
			private static AtomicInteger s_active_object_count = new AtomicInteger(0);
			private static MMapNode[] ZeroNexts = new MMapNode[0];


			internal Action<MMapNode> OnResetValue;
			internal byte area = 0;
			internal MMapNode[] nextnodes = ZeroNexts;

			//private BitSet8 bitset;
			private bool mBlocked;
			private bool mAllCross;
			private ushort bx, by;
			private float px, py;
			private int value;
			private BlockMesh mesh;
			private float complexity;

			public override MapNode[] Nexts { get { return nextnodes; } }
			public BlockMesh Mesh { get { return mesh; } }
			public int BX { get { return bx; } }
			public int BY { get { return by; } }
			public float PosX { get { return px; } }
			public float PosY { get { return py; } }
			//public bool Blocked { get { return bitset.Get(0); } private set { bitset.Set(0, value); } }
			//public bool IsAllCross { get { return bitset.Get(1); } private set { bitset.Set(1, value); } }
			public bool Blocked { get { return mBlocked; } private set { mBlocked = value; } }
			public bool IsAllCross { get { return mAllCross; } private set { mAllCross = value; } }

			public byte AreaValue { get { return area; } }
            public int Value { get { return value; } }

            public MMapNode() { s_active_object_count++; }
            ~MMapNode() { s_active_object_count--; }

            internal void Init(MTerrain map, int x, int y)
            {
                this.bx = (ushort)x;
                this.by = (ushort)y;
                this.px = bx * map.map_data.CellW + map.map_data.CellW / 2;
                this.py = by * map.map_data.CellH + map.map_data.CellH / 2;
                this.value = map.map_data.GetValue(BX, BY);
                //this.Blocked = map.map_data.TestBlock(BX, BY);
				this.Blocked = map.map_data.TestBlock(BX, BY);

			}
            public override void Dispose()
            {
                mesh = null;
                nextnodes = null;
                OnResetValue = null;
            }

            internal bool resetValue(MTerrain mmap)
            {
                this.value = mmap.map_data.GetValue(BX, BY);
                var block = mmap.map_data.TestBlock(BX, BY);
                if (this.Blocked != block)
                {
                    this.Blocked = block;
                    if (OnResetValue != null)
                    {
                        OnResetValue.Invoke(this);
                    }
                    return true;
                }
                return false;
            }
            internal void resetNextNodes(MTerrain mmap)
            {
                this.mesh = BlockMesh.CreateMesh(bx, by, mmap);
                if (Blocked)
                {
                    this.nextnodes = ZeroNexts;
                    this.IsAllCross = false;
                    this.complexity = 0;
                }
                else
                {
                    int[][] near_table = GetNearTables(mmap.is_inclined);
                    using (var nexts = ListObjectPool<MMapNode>.AllocAutoRelease())
                    {
                        foreach (int[] offset in near_table)
                        {
                            int dx = bx + offset[0];
                            int dy = by + offset[1];
                            if (dx >= 0 && dx < mmap.xcount && dy >= 0 && dy < mmap.ycount)
                            {
                                MMapNode near = mmap.getMapNode(dx, dy);
                                if (near != null && !near.Blocked)
                                {
                                    nexts.Add(near);
                                }
                            }
                        }
                        this.nextnodes = nexts.ToArray();
                    }
                    this.IsAllCross = (near_table.Length == nextnodes.Length);
                    this.complexity = mmap.manhattan.cell_sqrt * (near_table.Length - nextnodes.Length);
                }
            }

            public override bool TestCross(MapNode father)
            {
                return !Blocked;
            }
            public override float GetG(MapNode target)
            {
                MMapNode t = (MMapNode)target;
                float ndx = this.bx - t.bx;
                float ndy = this.by - t.by;
                //sqrt (ndx * ndx + ndy * ndy)//
                return (float)Math.Sqrt((ndx * ndx) + (ndy * ndy)) + this.complexity;
            }
            public override float GetH(MapNode father)
            {
                if (father == this) return 0;
                MMapNode t = (MMapNode)father;
                if (this.bx != t.bx && this.by != t.by)
                {
                    //sqrt (1 * 1 + 1 * 1)//
                    return SQRT_TOW + t.complexity;// SQRT_TOW;
                }
                return SQRT_ONE + t.complexity;
            }
            private readonly static float SQRT_TOW = (float)Math.Sqrt(2);
            private readonly static float SQRT_ONE = 1;
            //----------------------------------------------------------------------------------------------------------------------------

            /// <summary>
            /// 和矩形碰撞
            /// </summary>
            /// <param name="x1"></param>
            /// <param name="y1"></param>
            /// <param name="x2"></param>
            /// <param name="y2"></param>
            /// <returns></returns>
            public bool TouchRect(float x1, float y1, float x2, float y2)
            {
                return (mesh != null && mesh.TouchRect(x1, y1, x2, y2));
            }
            /// <summary>
            /// 和线段检测碰撞
            /// </summary>
            /// <returns></returns>
            /// <param name="x1"></param>
            /// <param name="y1"></param>
            /// <param name="x2"></param>
            /// <param name="y2"></param>
            /// <returns></returns>
            public bool TouchLine(float x1, float y1, float x2, float y2)
            {
                return (mesh != null && mesh.TouchLine(x1, y1, x2, y2));
            }
            /// <summary>
            /// 获得线段和此碰撞最近的焦点
            /// </summary>
            /// <returns></returns>
            public bool GetLineTouchPoint(float sx, float sy, float dx, float dy, out float touch_x, out float touch_y, out float touch_distance)
            {
                if (mesh != null)
                {
                    return mesh.GetLineTouchPoint(sx, sy, dx, dy, out touch_x, out touch_y, out touch_distance);
                }
                touch_x = 0;
                touch_y = 0;
                touch_distance = 0;
                return false;
            }

            /// <summary>
            /// 单元格碰撞网格
            /// </summary>
            public class BlockMesh
            {
                /// <summary>
                /// 实例数量
                /// </summary>
                public static int ActiveObjectCount { get { return s_active_object_count.Value; } }
                private static AtomicInteger s_active_object_count = new AtomicInteger(0);
                private BlockMesh() { s_active_object_count++; }
                ~BlockMesh() { s_active_object_count--; }

                private BitSet8 c_block = new BitSet8(0xFF);
                private CommonLang.Geometry.Vector2 c_point_TL;
                private CommonLang.Geometry.Vector2 c_point_TR;
                private CommonLang.Geometry.Vector2 c_point_BR;
                private CommonLang.Geometry.Vector2 c_point_BL;

                private bool c_block_T { get { return c_block.Get(0); } set { c_block.Set(0, value); } }
                private bool c_block_L { get { return c_block.Get(1); } set { c_block.Set(1, value); } }
                private bool c_block_R { get { return c_block.Get(2); } set { c_block.Set(2, value); } }
                private bool c_block_B { get { return c_block.Get(3); } set { c_block.Set(3, value); } }

                public bool IsTestTop { get { return c_block_T; } }
                public bool IsTestLeft { get { return c_block_L; } }
                public bool IsTestRight { get { return c_block_R; } }
                public bool IsTestBottom { get { return c_block_B; } }

                internal static BlockMesh CreateMesh(int bx, int by, MTerrain mmap)
                {
                    bool c_block_L = mmap.touchMapBlock(bx - 1, by);
                    bool c_block_R = mmap.touchMapBlock(bx + 1, by);
                    bool c_block_T = mmap.touchMapBlock(bx, by - 1);
                    bool c_block_B = mmap.touchMapBlock(bx, by + 1);
                    // 四周全部阻挡，忽略 //
                    if (c_block_L && c_block_R && c_block_T && c_block_B)
                    {
                        return null;
                    }
                    // 四周全部非阻挡，忽略 //
                    if (!c_block_L && !c_block_R && !c_block_T && !c_block_B)
                    {
                        return null;
                    }
                    BlockMesh ret = new BlockMesh();
                    float cellw = mmap.map_data.CellW;
                    float cellh = mmap.map_data.CellH;
                    float c_sx = bx * cellw;
                    float c_sy = by * cellh;
                    float c_dx = c_sx + cellw;
                    float c_dy = c_sy + cellh;
                    ret.c_point_TL = new CommonLang.Geometry.Vector2(c_sx, c_sy);
                    ret.c_point_TR = new CommonLang.Geometry.Vector2(c_dx, c_sy);
                    ret.c_point_BR = new CommonLang.Geometry.Vector2(c_dx, c_dy);
                    ret.c_point_BL = new CommonLang.Geometry.Vector2(c_sx, c_dy);
                    ret.c_block_L = c_block_L;
                    ret.c_block_R = c_block_R;
                    ret.c_block_T = c_block_T;
                    ret.c_block_B = c_block_B;
                    return ret;
                }


                /// <summary>
                /// 和矩形碰撞
                /// </summary>
                /// <param name="x1"></param>
                /// <param name="y1"></param>
                /// <param name="x2"></param>
                /// <param name="y2"></param>
                /// <returns></returns>
                public bool TouchRect(float x1, float y1, float x2, float y2)
                {
                    return CMath.intersectRect(c_point_TL.X, c_point_TL.Y, c_point_BR.X, c_point_BR.Y, x1, y1, x2, y2);
                }

                /// <summary>
                /// 和线段检测碰撞
                /// </summary>
                /// <returns></returns>
                public bool TouchLine(float x1, float y1, float x2, float y2)
                {
                    // T
                    if (c_block_T && CMath.intersectLine(c_point_TL.X, c_point_TL.Y, c_point_TR.X, c_point_TR.Y, x1, y1, x2, y2))
                    {
                        return true;
                    }
                    // L
                    if (c_block_L && CMath.intersectLine(c_point_TL.X, c_point_TL.Y, c_point_BL.X, c_point_BL.Y, x1, y1, x2, y2))
                    {
                        return true;
                    }
                    // R
                    if (c_block_R && CMath.intersectLine(c_point_TR.X, c_point_TR.Y, c_point_BR.X, c_point_BR.Y, x1, y1, x2, y2))
                    {
                        return true;
                    }
                    // B
                    if (c_block_B && CMath.intersectLine(c_point_BL.X, c_point_BL.Y, c_point_BR.X, c_point_BR.Y, x1, y1, x2, y2))
                    {
                        return true;
                    }
                    return false;
                }


                /// <summary>
                /// 获得线段和此碰撞最近的焦点
                /// </summary>
                /// <returns></returns>
                public bool GetLineTouchPoint(float sx, float sy, float dx, float dy, out float touch_x, out float touch_y, out float touch_distance)
                {
                    CommonLang.Geometry.Vector2 p0 = new CommonLang.Geometry.Vector2(sx, sy);
                    CommonLang.Geometry.Vector2 p1 = new CommonLang.Geometry.Vector2(dx, dy);
                    CommonLang.Geometry.Vector2 touch = p0;
                    CommonLang.Geometry.Vector2 min_p = p0;
                    float min_d = float.MaxValue;
                    bool ret = false;
                    // T
                    if (c_block_T && LineLineIntersect(ref p0, ref p1, ref c_point_TL, ref c_point_TR, ref touch, ref min_p, ref min_d))
                    {
                        ret = true;
                    }
                    // R
                    if (c_block_R && LineLineIntersect(ref p0, ref p1, ref c_point_TR, ref c_point_BR, ref touch, ref min_p, ref min_d))
                    {
                        ret = true;
                    }
                    // B
                    if (c_block_B && LineLineIntersect(ref p0, ref p1, ref c_point_BL, ref c_point_BR, ref touch, ref min_p, ref min_d))
                    {
                        ret = true;
                    }
                    // L
                    if (c_block_L && LineLineIntersect(ref p0, ref p1, ref c_point_TL, ref c_point_BL, ref touch, ref min_p, ref min_d))
                    {
                        ret = true;
                    }
                    touch_x = min_p.X;
                    touch_y = min_p.Y;
                    touch_distance = min_d;
                    return ret;
                }

                public void ToLines(List<CommonLang.Geometry.Line2> ret)
                {
                    if (c_block_T)
                    {
                        ret.Add(new CommonLang.Geometry.Line2(c_point_TL, c_point_TR));
                    }
                    if (c_block_R)
                    {
                        ret.Add(new CommonLang.Geometry.Line2(c_point_TR, c_point_BR));
                    }
                    if (c_block_B)
                    {
                        ret.Add(new CommonLang.Geometry.Line2(c_point_BL, c_point_BR));
                    }
                    if (c_block_L)
                    {
                        ret.Add(new CommonLang.Geometry.Line2(c_point_TL, c_point_BL));
                    }
                }

                private bool LineLineIntersect(
                    ref CommonLang.Geometry.Vector2 sp0,
                    ref CommonLang.Geometry.Vector2 sp1,
                    ref CommonLang.Geometry.Vector2 dp0,
                    ref CommonLang.Geometry.Vector2 dp1,
                    ref CommonLang.Geometry.Vector2 out_touch,
                    ref CommonLang.Geometry.Vector2 out_min_p,
                    ref float out_min_d)
                {
                    if (CommonLang.Geometry.CollisionMath.LineLineIntersect(sp0, sp1, dp0, dp1, out out_touch))
                    {
                        float d = (out_touch - sp0).LengthSquared();
                        if (d < out_min_d)
                        {
                            out_min_p = out_touch;
                            out_min_d = d;
                            return true;
                        }
                    }
                    return false;
                }
            }

        }

        /// <summary>
        /// 曼哈顿寻路路点
        /// </summary>
        public class MWayPoint : WayPoint, IEnumerable<MWayPoint>
        {
            /// <summary>
            /// 实例数量
            /// </summary>
            public static int ActiveObjectCount { get { return s_active_object_count.Value; } }
            private static AtomicInteger s_active_object_count = new AtomicInteger(0);

            private float _px, _py;
            private bool _center;
            public int BX { get; private set; }
            public int BY { get; private set; }
            public MWayPoint Next { get { return base.next as MWayPoint; } }
            public MWayPoint Tail { get { return base.tail as MWayPoint; } }
            public float PosX { get { return _px; } }
            public float PosY { get { return _py; } }
            public bool IsCenter { get { return _center; } }

            internal MWayPoint(MMapNode node)
                : base(node)
            {
                s_active_object_count++;
                this.BX = node.BX;
                this.BY = node.BY;
                this._px = node.PosX;
                this._py = node.PosY;
                this._center = true;
            }
            ~MWayPoint()
            {
                s_active_object_count--;
            }
            internal void SetPos(float x, float y)
            {
                this._px = x;
                this._py = y;
                this._center = (_px == (node as MMapNode).PosX && _py == (node as MMapNode).PosY);
            }
            public override void Dispose()
            {
                base.Dispose();
            }
            public override WayPoint Clone()
            {
                var ret = new MWayPoint(this.node as MMapNode);
                ret._px = this._px;
                ret._px = this._px;
                if (this.next != null)
                {
                    ret.LinkNext(this.next.Clone());
                }
                return ret;
            }

            public float GetTotalDistance()
            {
                float ret = 0;
                MWayPoint cur = this;
                while (cur != null)
                {
                    MWayPoint nex = cur.Next;
                    if (cur != null && nex != null)
                    {
                        ret += CMath.getDistance(cur.PosX, cur.PosY, nex.PosX, nex.PosY);
                    }
                    cur = nex;
                }
                return ret;
            }

#region IEnumerable
            IEnumerator<MWayPoint> IEnumerable<MWayPoint>.GetEnumerator()
            {
                return new Iterator(this);
            }
            System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
            {
                return new Iterator(this);
            }

            private struct Iterator : IEnumerator<MWayPoint>
            {
                private MWayPoint root;
                private MWayPoint current;
                public MWayPoint Current { get { return current; } }
                object System.Collections.IEnumerator.Current { get { return current; } }
                public Iterator(MWayPoint root)
                {
                    this.root = root;
                    this.current = null;
                }
                public void Dispose()
                {
                    this.current = null;
                }
                public bool MoveNext()
                {
                    if (current == null)
                    {
                        this.current = root;
                    }
                    else
                    {
                        this.current = current.Next;
                    }
                    return current != null;
                }
                public void Reset()
                {
                    this.current = null;
                }
            }
#endregion
        }
        

    }
}