using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using OfficeOpenXml.FormulaParsing.Excel.Functions.Math;
using WIDESEAWCS_Core.Helper;
using WIDESEAWCS_DTO.PlacedBlockDTO;
using WIDESEAWCS_DTO.TaskInfo;
using WIDESEAWCS_IBasicInfoService;

namespace WIDESEAWCS_BasicInfoService
{
    /// <summary>
    /// 货物放置服务，提供集装箱内货物摆放位置计算功能
    /// </summary>
    /// <remarks>
    /// 主要功能包括： <br/>
    /// 1. 根据货物尺寸自动计算最优摆放位置 <br/>
    /// 2. 支持横向/纵向两种摆放方式 <br/>
    /// 3. 考虑吸盘尺寸、容器边界等物理限制 <br/>
    /// 4. 提供任务位置坐标转换功能 <br/>
    ///  <br/>
    /// 核心参数： <br/>
    /// - SPACING: 货物间最小间距 <br/>
    /// - MaxRotateLength: 最大旋转长度限制 <br/>
    /// - MaxY/MinY: Y轴坐标限制 <br/>
    /// - SuctionLength/Width: 吸盘尺寸参数
    /// </remarks>
    public class PlaceBlockService
    {
        /// <summary>
        /// 获取配置文件中"Spacing"键对应的整数值，表示间距值
        /// </summary>
        public static int SPACING = AppSettings.GetValue("Spacing").ObjToInt();

        /// <summary>
        /// 获取或设置最大旋转长度配置值
        /// </summary>
        public static int MaxRotateLength = AppSettings.GetValue("MaxRotateLength").ObjToInt();

        /// <summary>
        /// 最大Y坐标限制（毫米）
        /// </summary>
        public const int MaxY = 600;

        /// <summary>
        /// 最小横向Y坐标限制（毫米）
        /// </summary>
        public static int MinY = AppSettings.GetValue("MinY").ObjToInt();

        /// <summary>
        /// 旋转抓取Y轴偏移量（毫米）
        /// </summary>
        public static int RotateYOffset = AppSettings.GetValue("RotateYOffset").ObjToInt();

        /// <summary>
        /// 吸盘横向长度
        /// </summary>
        public const int SuctionLengthH = 920;

        /// <summary>
        /// 吸盘横向宽度
        /// </summary>
        public const int SuctionWidthH = 530;

        /// <summary>
        /// 吸盘纵向长度
        /// </summary>
        public const int SuctionLengthZ = 530;

        /// <summary>
        /// 吸盘纵向宽度
        /// </summary>
        public const int SuctionWidthZ = 130;

        /// <summary>
        /// 容器尺寸
        /// </summary>
        public ContainerSize ContainerSize { get; private set; }

        /// <summary>
        /// 已放置货物
        /// </summary>
        public List<PlacedBlock> PlacedBlocks { get; private set; }

        /// <summary>
        /// 容器地板的放置块实例
        /// </summary>
        private readonly PlacedBlock containerFloor;

        /// <summary>
        /// 初始化放置区块服务
        /// </summary>
        /// <param name="containerSize">容器尺寸</param>
        /// <param name="placedBlocks">已放置区块列表，可选参数</param>
        /// <remarks>
        /// 构造函数会初始化容器尺寸和已放置区块列表。
        /// 如果未提供placedBlocks或列表为空，将创建新的空列表。
        /// 同时会创建表示容器底部的PlacedBlock对象。
        /// </remarks>
        public PlaceBlockService(ContainerSize containerSize, List<PlacedBlock>? placedBlocks = null)
        {
            containerSize.Length = containerSize.Length;
            containerSize.Width = containerSize.Width;
            ContainerSize = containerSize;
            if (placedBlocks == null || placedBlocks.Count == 0)
            {
                PlacedBlocks = new List<PlacedBlock>();
            }
            else
            {
                PlacedBlocks = placedBlocks;
            }
            containerFloor = new PlacedBlock(new Point3D(0, 0, 0), ContainerSize.Length, ContainerSize.Width, 0);

            //containerFloor = new PlacedBlock(new Point3D(SPACING, SPACING, 0), ContainerSize.Length - 2 * SPACING, ContainerSize.Width - 2 * SPACING, 0);
        }

        /// <summary>
        /// 根据给定的长宽高寻找合适的放置位置
        /// </summary>
        /// <param name="length">块的长度</param>
        /// <param name="width">块的宽度</param>
        /// <param name="height">块的高度</param>
        /// <returns>可放置的3D坐标点，若无法放置则返回null</returns>
        /// <remarks>
        /// 方法会自动处理长宽参数，确保length >= width
        /// 在放置前会先检查块的有效性
        /// </remarks>
        public Point3D? PlaceBlock(int length, int width, int height)
        {
            int tempLength = length;
            int tempWidth = width;

            if (length < width)
            {
                length = tempWidth;
                width = tempLength;
            }

            if (!IsValidBlock(length, width, height))
                return null;

            return FindStackablePosition(length, width, height);
        }

        /// <summary>
        /// 根据给定的长、宽、高和边缘值放置一个块，并返回可放置的位置
        /// </summary>
        /// <param name="length">块的长度</param>
        /// <param name="width">块的宽度</param>
        /// <param name="height">块的高度</param>
        /// <param name="edge">边缘值</param>
        /// <returns>可放置的位置信息，若块无效则返回null</returns>
        public TaskPosition? PlaceBlock(int length, int width, int height, int edge)
        {
            int tempLength = length;
            int tempWidth = width;

            if (length < width)
            {
                length = tempWidth;
                width = tempLength;
            }

            if (!IsValidBlock(length, width, height))
                return null;

            return FindStackablePosition(length, width, height, edge);
        }

        /// <summary>
        /// 检查给定的长宽高是否构成有效的块体尺寸
        /// </summary>
        /// <param name="l">长度</param>
        /// <param name="w">宽度</param>
        /// <param name="h">高度</param>
        /// <returns>如果尺寸有效返回true，否则返回false</returns>
        /// <remarks>
        /// 有效块体需满足：长宽高都大于0，且长宽不超过容器尺寸减去两倍间距，高度不超过容器高度
        /// </remarks>
        private bool IsValidBlock(int l, int w, int h)
        {
            return l > 0 && w > 0 && h > 0 &&
                   l <= ContainerSize.Length &&
                   w <= ContainerSize.Width &&
                   h < ContainerSize.Height;
        }

        //private bool IsValidBlock(int l, int w, int h)
        //{
        //    return l > 0 && w > 0 && h > 0 &&
        //           l <= ContainerSize.Length - 2 * SPACING &&
        //           w <= ContainerSize.Width - 2 * SPACING &&
        //           h < ContainerSize.Height;
        //}

        /// <summary>
        /// 在容器中查找可放置指定尺寸块体的有效位置
        /// </summary>
        /// <param name="l">块体长度</param>
        /// <param name="w">块体宽度</param>
        /// <param name="h">块体高度</param>
        /// <returns>可放置位置的3D坐标点，若无合适位置则返回null</returns>
        /// <remarks>
        /// 1. 通过分析已放置块体生成候选支撑层
        /// 2. 考虑容器底部和支撑块的不同间隔规则
        /// 3. 优先检查角落位置以提高搜索效率
        /// </remarks>
        private Point3D? FindStackablePosition(int l, int w, int h)
        {
            // 生成候选支撑层（包含容器底部）
            var candidateLayers = PlacedBlocks
                .Select(b => b.Position.Z + b.Height)
                .Append(0)
                .Distinct()
                .OrderBy(z => z)
                .ToList();

            foreach (var baseZ in candidateLayers)
            {
                if (baseZ + h > ContainerSize.Height) continue;

                // 获取当前层的支撑块（包含虚拟容器底部）
                var supports = GetSupportBlocks(baseZ);

                foreach (var support in supports)
                {
                    // 计算有效叠放区域（修正间隔逻辑）
                    int xStart = support.Position.X;
                    int yStart = support.Position.Y;

                    // 容器底部支撑必须内缩间隔（即使尺寸相同）
                    if (support == containerFloor)
                    {
                        xStart = support.Position.X;
                        yStart = support.Position.Y;
                    }

                    int xEnd = support.Position.X + support.Length - l;
                    int yEnd = support.Position.Y + support.Width - w;

                    // 普通支撑块仅在尺寸不同时加间隔
                    if (support != containerFloor &&
                       (l != support.Length && w != support.Width))
                    {
                        xStart += SPACING;
                        yStart += SPACING;
                        xEnd -= SPACING;
                        yEnd -= SPACING;
                    }

                    // 最终容器边界约束
                    xEnd = Math.Min(xEnd, ContainerSize.Length - l - SPACING);
                    yEnd = Math.Min(yEnd, ContainerSize.Width - w - SPACING);

                    if (xStart > xEnd || yStart > yEnd) continue;

                    // 优化搜索：优先角落位置
                    for (int x = xStart; x <= xEnd; x += 10)
                    {
                        for (int y = yStart; y <= yEnd; y += 10)
                        {
                            var candidate = new Point3D(x, y, baseZ);
                            if (IsPositionValid(candidate, l, w, h))
                            {
                                var placed = new PlacedBlock(candidate, l, w, h);
                                //PlacedBlocks.Add(placed);
                                return candidate;
                            }
                        }
                    }
                }
            }
            return null;
        }

        /// <summary>
        /// 在容器中查找可堆叠位置
        /// </summary>
        /// <param name="l">物品长度</param>
        /// <param name="w">物品宽度</param>
        /// <param name="h">物品高度</param>
        /// <param name="edge">边缘类型</param>
        /// <returns>返回找到的有效任务位置，若找不到则返回null</returns>
        /// <remarks>
        /// 1. 生成候选支撑层（包含容器底部）
        /// 2. 遍历每层支撑块计算有效叠放区域
        /// 3. 考虑容器边界约束和间隔规则
        /// 4. 优先检查角落位置以提高搜索效率
        /// </remarks>
        private TaskPosition? FindStackablePosition(int l, int w, int h, int edge)
        {
            // 生成候选支撑层（包含容器底部）
            var candidateLayers = PlacedBlocks
                .Select(b => b.Position.Z + b.Height)
                .Append(0)
                .Distinct()
                .OrderBy(z => z)
                .ToList();

            foreach (var baseZ in candidateLayers)
            {
                if (baseZ + h > ContainerSize.Height) continue;

                // 获取当前层的支撑块（包含虚拟容器底部）
                var supports = GetSupportBlocks(baseZ);

                foreach (var support in supports)
                {
                    // 计算有效叠放区域（修正间隔逻辑）
                    int xStart = support.Position.X;
                    int yStart = support.Position.Y;

                    int xEnd = support.Position.X + support.Length - l;
                    int yEnd = support.Position.Y + support.Width - w;

                    // 最终容器边界约束
                    xEnd = Math.Min(xEnd, ContainerSize.Length - l);
                    yEnd = Math.Min(yEnd, ContainerSize.Width - w);

                    if (xStart > xEnd || yStart > yEnd) continue;

                    // 优化搜索：优先角落位置
                    for (int x = xStart; x <= xEnd; x += 10)
                    {
                        for (int y = yStart; y <= yEnd; y += 10)
                        {
                            var candidate = new Point3D(x, y, baseZ);
                            if (IsPositionValid(candidate, l, w, h))
                            {
                                TaskPosition taskPosition = GetTaskPosition(candidate, l, w, h, edge);
                                if (IsPositionValid(taskPosition))
                                {
                                    return taskPosition;
                                }

                            }
                        }
                    }
                }
            }
            return null;
        }

        /// <summary>
        /// 获取指定高度层的支撑块
        /// </summary>
        /// <param name="baseZ">需要支撑的高度层</param>
        /// <returns>按面积从大到小排序的支撑块集合，当baseZ=0且无支撑块时返回容器底部</returns>
        private IEnumerable<PlacedBlock> GetSupportBlocks(int baseZ)
        {
            var blocks = PlacedBlocks
                .Where(b => b.Position.Z + b.Height == baseZ)
                .OrderBy(b => b.Position.X)
                .ThenBy(b => b.Position.Y)
                /*.OrderByDescending(b => b.Length * b.Width)*/
                .ToList();

            // 当baseZ=0时添加容器底部支撑
            if (baseZ == 0 && blocks.Count == 0)
            {
                return new List<PlacedBlock> { containerFloor };
            }

            return blocks;
        }

        /// <summary>
        /// 检查指定位置是否有效，即该位置是否可以放置指定尺寸的块体
        /// </summary>
        /// <param name="pos">要检查的位置坐标</param>
        /// <param name="l">块体长度</param>
        /// <param name="w">块体宽度</param>
        /// <param name="h">块体高度</param>
        /// <returns>如果位置有效且不与其他已放置块体重叠则返回true，否则返回false</returns>
        /// <remarks>
        /// 检查条件包括：
        /// 1. 是否超出容器尺寸限制
        /// 2. X坐标是否超过1600限制
        /// 3. 当X坐标超过MaxY且长度超过MaxRotateLength时的限制
        /// 4. 是否与已放置的块体发生重叠（考虑SPACING间距）
        /// </remarks>
        private bool IsPositionValid(Point3D pos, int l, int w, int h)
        {
            if (pos.X + l > ContainerSize.Length ||
                pos.Y + w > ContainerSize.Width)
                return false;

            if (pos.X > 1600)
                return false;

            if (pos.X > MaxY && l > MaxRotateLength) return false;

            var newBlock = new PlacedBlock(pos, l, w, h);
            return !PlacedBlocks.Any(existing =>
            {
                bool xOverlap = newBlock.Position.X < existing.Position.X + existing.Length + SPACING &&
                              newBlock.Position.X + newBlock.Length + SPACING > existing.Position.X;

                bool yOverlap = newBlock.Position.Y < existing.Position.Y + existing.Width + SPACING &&
                              newBlock.Position.Y + newBlock.Width + SPACING > existing.Position.Y;

                bool zOverlap = newBlock.Position.Z < existing.Position.Z + existing.Height &&
                              newBlock.Position.Z + h > existing.Position.Z;

                return xOverlap && yOverlap && zOverlap;
            });
        }

        //private bool IsPositionValid(Point3D pos, int l, int w, int h)
        //{
        //    // 边界检查（含容器边缘间隔）
        //    if (pos.X < SPACING ||
        //        pos.Y < SPACING ||
        //        pos.X + l > ContainerSize.Length - SPACING ||
        //        pos.Y + w > ContainerSize.Width - SPACING)
        //        return false;

        //    if (pos.X > 1600)
        //        return false;

        //    if (pos.X > MaxY && l > MaxRotateLength) return false;

        //    // 三维碰撞检测
        //    var newBlock = new PlacedBlock(pos, l, w, h);
        //    return !PlacedBlocks.Any(existing =>
        //    {
        //        bool xOverlap = newBlock.Position.X < existing.Position.X + existing.Length + SPACING &&
        //                      newBlock.Position.X + newBlock.Length + SPACING > existing.Position.X;

        //        bool yOverlap = newBlock.Position.Y < existing.Position.Y + existing.Width + SPACING &&
        //                      newBlock.Position.Y + newBlock.Width + SPACING > existing.Position.Y;

        //        bool zOverlap = newBlock.Position.Z < existing.Position.Z + existing.Height &&
        //                      newBlock.Position.Z + h > existing.Position.Z;

        //        return xOverlap && yOverlap && zOverlap;
        //    });
        //}

        /// <summary>
        /// 检查任务位置是否有效
        /// </summary>
        /// <param name="pos">要检查的任务位置</param>
        /// <returns>如果Y轴坐标在有效范围内返回true，否则返回false</returns>
        private bool IsPositionValid(TaskPosition pos)
        {
            return pos.PutPositionY <= MaxY && pos.PutPositionY >= 0 && pos.TakePositionY >= 0;
        }

        /// <summary>
        /// 根据给定的三维坐标和尺寸参数计算任务位置信息
        /// </summary>
        /// <param name="point3D">起始三维坐标点</param>
        /// <param name="length">物体长度</param>
        /// <param name="width">物体宽度</param>
        /// <param name="height">物体高度</param>
        /// <param name="edge">边缘标识(0/1)</param>
        /// <returns>包含取放货位置信息的TaskPosition对象</returns>
        /// <remarks>
        /// 该方法根据物体尺寸自动选择单吸盘或双吸盘模式，
        /// 并计算吸盘中心点位置，同时处理边界条件限制。
        /// 横向放置时最小Y坐标为155，纵向时为350，最大Y坐标为700。
        /// </remarks>
        public TaskPosition GetTaskPosition(Point3D point3D, int length, int width, int height, int edge)
        {
            //放货位置板材中心点
            Point3D putCenter = new Point3D(point3D.X + length / 2, point3D.Y + width / 2, point3D.Z + height / 2);

            //取货位置板材中心点
            Point3D takeCenter = new Point3D(length / 2, width / 2, height / 2);

            //吸盘长530 间隔660  最大920 吸盘宽130
            int positionR = 1;

            int takePositionX = 0;
            int takePositionY = 0;
            int takePositionZ = 0;
            int putPositionX = 0;
            int putPositionY = 0;
            int putPositionZ = 0;

            //1.如果长度大于920，宽度大于等于300，则可以使用双吸盘横向吸取
            if (length > 920) //横向双吸
            {
                //吸盘尺寸
                Point3D deviceCenter = new Point3D(530 / 2, 920 / 2, 0);

                positionR = 1;
                takePositionX = (takeCenter.Y - deviceCenter.X);
                takePositionY = (takeCenter.X - deviceCenter.Y);
                takePositionZ = 10;

                putPositionX = (putCenter.Y - deviceCenter.X);
                putPositionY = (putCenter.X - deviceCenter.Y);
                putPositionZ = point3D.Z;
            }
            else//横向单吸
            {
                //吸盘尺寸
                Point3D deviceCenter = new Point3D(530 / 2, 130 / 2, 0);

                positionR = 1;
                takePositionX = (takeCenter.Y - deviceCenter.X);
                takePositionY = (takeCenter.X - deviceCenter.Y);
                takePositionZ = 10;

                putPositionX = (putCenter.Y - deviceCenter.X);
                putPositionY = (putCenter.X - deviceCenter.Y);
                putPositionZ = point3D.Z;
            }

            if (takePositionY <= MinY)
            {
                takePositionY = 0;
                putPositionY = point3D.X + MinY;
            }
            else
            {
                takePositionY -= MinY;
            }

            if (putPositionY > MaxY)
            {
                int moreY = putPositionY - MaxY;
                if (takePositionY - moreY > 0)
                {
                    takePositionY -= moreY;
                    putPositionY = MaxY;
                }
                else if (Math.Abs(takePositionY - moreY) < SPACING)
                {
                    takePositionY = 0;
                    putPositionY = Math.Abs(takePositionY - moreY) + MinY;
                }
                else
                {
                    int count = PlacedBlocks.Where(x => x.Position.Y == 10).Count();
                    putPositionY = point3D.X - 920 + 130 + RotateYOffset;
                    takePositionY = length - MinY - 130 - RotateYOffset;
                    if (putPositionY < 0 && takePositionY + putPositionY >= 0)
                    {
                        takePositionY += putPositionY;
                        putPositionY = 0;
                    }
                    positionR = 2;
                }
            }

            if (positionR == 2 && edge == 0)
            {
                takePositionX = width - 530;
                putPositionX = point3D.Y;
            }
            else if (positionR == 2 && edge == 1)
            {
                takePositionX = 0;
                putPositionX = point3D.Y + width - 530;
            }
            else if (positionR == 1 && edge == 1)
            {
                if(width > ContainerSize.Width)
                {
                    takePositionX = 0;
                    putPositionX = point3D.Y;
                }
                else
                {
                    takePositionX = width - 530;
                    putPositionX = point3D.Y + (width - 530);
                }
            }
            else if (positionR == 1 && edge == 0)
            {
                if (putPositionX < 0)
                {
                    takePositionX = 0;
                    putPositionX = point3D.Y;
                }
            }

            if (takePositionY < 0 && Math.Abs(takePositionY) < SPACING)
            {
                takePositionY = 0;
            }

            TaskPosition taskPosition = new TaskPosition()
            {
                PositionR = positionR,
                TakePositionX = takePositionX,
                TakePositionY = takePositionY,
                TakePositionZ = takePositionZ,
                PutPositionX = putPositionX,
                PutPositionY = putPositionY,
                PutPositionZ = putPositionZ,
                TakeCenterPositionX = takeCenter.X,
                TakeCenterPositionY = takeCenter.Y,
                TakeCenterPositionZ = takeCenter.Z,
                PutCenterPositionX = putCenter.X,
                PutCenterPositionY = putCenter.Y,
                PutCenterPositionZ = putCenter.Z,
                PositionX = point3D.X,
                PositionY = point3D.Y,
                PositionZ = point3D.Z
            };

            return taskPosition;
        }
    }
}