using System;
using Framework;
using Gameplay.Area;
using Gameplay.Unit;
using Gameplay.Level;
using Gameplay.Unit.Data;
using Gameplay.Area.Around;
using System.Collections.Generic;
using static Gameplay.Level.LevelData;

namespace Gameplay.AI
{
    public static class AIUtils
    {
        private static List<GameUnit> inSightEnemies = new List<GameUnit>(16);
        private static Dictionary<GameUnit, int> inSightDistanceList = new Dictionary<GameUnit, int>(16);

        private static List<GameUnit> allFriends = new List<GameUnit>(16);
        private static List<GameUnit> friendsInSight = new List<GameUnit>(16);

        private static Dictionary<int, int> patrolDistanceList = new Dictionary<int, int>(64);

        /// <summary>
        /// 寻找锁敌范围内最近的敌人
        /// </summary>
        public static GameUnit FindNearestEnemyInSightDistance(GameUnit owner)
        {
            try
            {
                if (owner == null) return null;

                var map = LevelManager.Instance.CurrentLevel.Map;
                if (map == null) return null;

                inSightEnemies.Clear();
                inSightDistanceList.Clear();
                GameUnitManager.instance.characterManager.SearchEnemies(owner, inSightEnemies);
                var ownerCellIndex = owner.transData?.cellIndex;
                for (var i = 0; i < inSightEnemies.Count; i++)
                {
                    var enemy = inSightEnemies[i];
                    if (enemy == null || enemy.statusData.isDead)
                    {
                        continue;
                    }

                    var enemyCellIndex = enemy.transData?.cellIndex;

                    if (!ownerCellIndex.HasValue || !enemyCellIndex.HasValue)
                    {
                        continue;
                    }

                    var distance = MapUtils.Distance(map, ownerCellIndex.Value, enemyCellIndex.Value);
                    if (distance <= owner.fightData.findEnemyRange &&
                        enemy.statusData.CheckCanBeTarget(owner, (int)owner.fightData.findEnemyRange))
                    {
                        inSightDistanceList.Add(enemy, distance);
                    }
                }

                if (inSightDistanceList.Count <= 0)
                {
                    return null;
                }
                else
                {
                    var minDistance = float.MaxValue;
                    GameUnit nearestEnemy = null;
                    foreach (var pair in inSightDistanceList)
                    {
                        if (minDistance > pair.Value)
                        {
                            minDistance = pair.Value;
                            nearestEnemy = pair.Key;
                        }
                    }

                    return nearestEnemy;
                }
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.FindNearestEnemyInSightDistance error: {0}", e);
                return null;
            }
        }

        /// <summary>
        /// 寻找锁敌范围内的友军
        /// </summary>
        public static List<GameUnit> FindFriendsInSightDistance(GameUnit owner)
        {
            try
            {
                if (owner == null) return null;

                var map = LevelManager.Instance.CurrentLevel.Map;
                if (map == null) return null;

                allFriends.Clear();
                friendsInSight.Clear();

                GameUnitManager.instance.characterManager.SearchFriends(owner, allFriends);

                var ownerCellIndex = owner.transData?.cellIndex;
                for (var i = 0; i < allFriends.Count; i++)
                {
                    var friend = allFriends[i];
                    if (friend == null || friend.GetID() == owner.GetID())
                    {
                        continue;
                    }

                    var friendCellIndex = friend.transData?.cellIndex;
                    if (!ownerCellIndex.HasValue || !friendCellIndex.HasValue)
                    {
                        continue;
                    }

                    var distance = MapUtils.Distance(map, ownerCellIndex.Value, friendCellIndex.Value);
                    if (distance <= owner.fightData.findEnemyRange)
                    {
                        friendsInSight.Add(friend);
                    }
                }

                return friendsInSight;
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.FindFriendsInSightDistance error: {0}", e);
                return null;
            }
        }

        /// <summary>
        /// 寻找范围内最近的敌方npc
        /// </summary>
        public static GameUnit FindNearestEnemyNpcInShootRange(GameUnit owner)
        {
            try
            {
                var enemyNpc = FindEnemyNpcInSight(owner);
                if (enemyNpc == null || enemyNpc.Count <= 0) return null;
                GameUnit nearestEnemy = null;
                var minDistance = float.MaxValue;
                foreach (var pair in enemyNpc)
                {
                    if (minDistance > pair.Value)
                    {
                        minDistance = pair.Value;
                        nearestEnemy = pair.Key;
                    }
                }

                return nearestEnemy;
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.FindNearestEnemyNpcInShootRange error: {0}", e);
                return null;
            }
        }

        /// <summary>
        /// 获取距离自己最近的单位
        /// </summary>
        public static GameUnit GetNearestGameUnit(GameUnit owner, GameUnit newUnit, GameUnit unit)
        {
            try
            {
                if (owner == null || newUnit == null || unit == null) return null;

                var map = LevelManager.Instance.CurrentLevel.Map;
                if (map == null) return null;

                var ownerCellIndex = owner.transData?.cellIndex;
                var unitCellIndex = unit.transData?.cellIndex;
                var newUnitCellIndex = newUnit.transData?.cellIndex;
                if (!ownerCellIndex.HasValue || !unitCellIndex.HasValue || !newUnitCellIndex.HasValue) return null;

                var distance = MapUtils.Distance(map, ownerCellIndex.Value, unitCellIndex.Value);
                var newDistance = MapUtils.Distance(map, ownerCellIndex.Value, newUnitCellIndex.Value);
                return distance <= newDistance ? unit : newUnit;
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.GetNearestGameUnit error: {0}", e);
                // 异常返回默认单位
                return unit;
            }
        }

        /// <summary>
        /// 寻找最近的巡逻点位
        /// </summary>
        public static int FindNearestPointInPatrolInfo(GameUnit owner, List<PatrolInfo> patrolInfos)
        {
            try
            {
                if (owner == null) return Constants.INVALID_ID;

                var map = LevelManager.Instance.CurrentLevel.Map;
                if (map == null) return Constants.INVALID_ID;

                patrolDistanceList.Clear();
                var ownerCellIndex = owner.transData?.cellIndex;
                for (var i = 0; i < patrolInfos.Count; i++)
                {
                    var point = map.BlockPosition2TGSCellIndex(patrolInfos[i].patrolPoint);

                    if (!ownerCellIndex.HasValue || point == Constants.INVALID_ID)
                    {
                        continue;
                    }

                    patrolDistanceList.Add(i,
                        MapUtils.Distance(map, ownerCellIndex.Value, point));
                }

                var minDistance = int.MaxValue;
                int nearestPoint = 0;
                foreach (var pair in patrolDistanceList)
                {
                    if (minDistance > pair.Value)
                    {
                        minDistance = pair.Value;
                        nearestPoint = pair.Key;
                    }
                }

                return nearestPoint;
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.FindNearestPointInPatrolInfo error: {0}", e);
                // 异常返回第一个索引点
                return 0;
            }
        }

        /// <summary>
        /// 巡逻点位转换为格子索引
        /// </summary>
        public static int GetPatrolPointIndexFromVector2Int(Map map, int patrolIndex, List<PatrolInfo> patrolInfos)
        {
            try
            {
                if (map == null || patrolIndex >= patrolInfos.Count) return -1;
                var patrolInfo = patrolInfos[patrolIndex];
                if (patrolInfo == null) return -1;
                return map.BlockPosition2TGSCellIndex(patrolInfo.patrolPoint);
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.GetPatrolPointIndexFromVector2Int error: {0}", e);
                // 异常返回无效格子索引
                return -1;
            }
        }

        /// <summary>
        /// 是否需要停掉AI
        /// </summary>
        public static bool IsNeedStop(GameUnit owner)
        {
            return owner.statusData.isRetreat || owner.statusData.isDead || owner.statusData.isOnVehicle ||
                   owner.statusData.isChaos || owner.statusData.isStun || owner.statusData.isLockPos;
        }

        /// <summary>
        /// 是否停止循环逻辑
        /// </summary>
        public static bool AINeedStopUpdate(Level.Level level)
        {
            if (level == null) return false;
            return level.IsPreparing() || level.IsEnd() || Math.Abs(level.GetSpeed() - 0f) < 0.01f;
        }

        /// <summary>
        /// 激活AI攻击
        /// </summary>
        public static void ActiveAIAttack(GameUnit owner)
        {
            try
            {
                if (owner == null) return;
                if (owner.statusData.isAttackActive) return;
                var map = LevelManager.Instance.CurrentLevel.Map;
                if (map == null) return;

                if (owner.controlData.targetEnemy != null)
                {
                    owner.statusData.isAttackActive = true;
                }
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.ActiveAIAttack error: {0}", e);
            }
        }

        /// <summary>
        /// 单位移动
        /// </summary>
        public static bool MoveTo(GameUnit owner, int cellIndex, bool cancelFollow = true)
        {
            try
            {
                if (owner == null || cellIndex == -1) return false;
                var map = LevelManager.Instance.CurrentLevel.Map;
                if (map == null) return false;
                var mapData = map.MapData;
                if (mapData == null) return false;
                var blockData = mapData.GetBlockData(cellIndex);
                if (blockData == null) return false;
                var typeProperty = blockData.GetTerrainTypeProperty();
                if (typeProperty == null || !typeProperty.selectable) return false;

                owner.MoveTo(cellIndex, cancelFollow);
                return true;
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.MoveTo error: {0}", e);
                return false;
            }
        }

        /// <summary>
        /// 单位撤退
        /// </summary>
        /// <returns></returns>
        public static bool MoveAway(GameUnit owner, GameUnit enemyUnit, bool cancelFollow = true)
        {
            try
            {
                if (enemyUnit == null) return false;
                var map = LevelManager.Instance.CurrentLevel.Map;
                if (map == null) return false;
                var mapData = map.MapData;
                if (mapData == null) return false;
                map.WorldPosition2BlockPosition(enemyUnit.Node.GetPosition(), out var targetEnemy2IntPos);
                var self2IntPos = map.TGSCellIndex2BlockPosition(owner.transData.cellIndex);
                var newSelf2IntPos = self2IntPos;
                newSelf2IntPos.x = Math.Clamp(
                    (self2IntPos.x - targetEnemy2IntPos.x) > 0 ? self2IntPos.x + 1 : self2IntPos.x - 1, 0,
                    map.MapData.Height - 1);
                newSelf2IntPos.y = Math.Clamp(
                    (self2IntPos.y - targetEnemy2IntPos.y) > 0 ? self2IntPos.y + 1 : self2IntPos.y - 1, 0,
                    map.MapData.Width - 1);
                if (self2IntPos == newSelf2IntPos) return false;
                var cellIndex = map.BlockPosition2TGSCellIndex(newSelf2IntPos);
                if (PathFinder.CanPass(cellIndex, owner))
                {
                    owner.MoveTo(cellIndex, cancelFollow);
                    return true;
                }

                return false;
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.MoveAway error: {0}", e);
                return false;
            }
        }

        /// <summary>
        /// AI 移动向敌人并检查
        /// </summary>
        public static void CheckAndMove(GameUnit owner, int cellIndex, bool cancelFollow = true)
        {
            try
            {
                if (!MoveTo(owner, cellIndex, cancelFollow)) return;

                if (owner.gameunitType != EGameUnitType.Character &&
                    owner.gameunitType != EGameUnitType.Vehicle) return;

                var units = AreaManager.instance.GetUnitsByCellIndex(cellIndex);
                foreach (var unit in units)
                {
                    if (unit.commonData.troopId == owner.commonData.troopId)
                    {
                    }
                    else
                    {
                        // 如果是敌人, 则设置敌人目标
                        if (unit.statusData.CheckCanBeTarget(owner, -1))
                        {
                            owner.controlData.markEnemy = unit;
                            owner.controlData.forceUpdateTarget = true;

                            return;
                        }
                    }
                }

                // 走到这里,说明没有目标,清空标记
                owner.controlData.markVehicle = null;
                owner.controlData.markEnemy = null;
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.CheckAndMove error: {0}", e);
            }
        }

        /// <summary>
        /// 判断是否有敌人重合 
        /// </summary>
        public static void CheckAreaIsOtherEnemyUnit(GameUnit owner, uint target)
        {
            try
            {
                if (owner == null || owner.statusData.isMoveing) return;
                var cellIndex = owner.transData.cellIndex;
                var units = AreaManager.instance.GetUnitsByCellIndex(cellIndex);
                var hasOther = false;
                foreach (var unit in units)
                {
                    if (unit == owner) continue;
                    if (!unit.commonData.canClaimStandCellIndex) continue;
                    if (unit.statusData.isMoveing) continue;
                    hasOther = true;
                    break;
                }

                if (!hasOther) return;
                if (target == Constants.INVALID_UINT_ID)
                {
                    MoveOtherCell(owner);
                }
                else
                {
                    var enemy = GameUnitManager.instance.infightUnits.Search(target);
                    if (enemy == null || enemy.statusData.isDead) return;
                    MoveOtherCanAttackCell(owner, enemy);
                }
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.CheckAreaIsOtherEnemyUnit error: {0}", e);
            }
        }

        /// <summary>
        /// 移动至周围可到达格子
        /// </summary>
        private static void MoveOtherCell(GameUnit owner, int maxDistance = 2)
        {
            try
            {
                var map = LevelManager.Instance.CurrentLevel?.Map;
                if (map == null || owner == null) return;
                var cellIndex = owner.transData.cellIndex;
                if (!AreaManager.instance.CheckContainsMoveUnit(cellIndex))
                    return;
                for (var i = 1; i <= maxDistance; i++)
                {
                    var minSteps = i - 1;
                    var maxSteps = i;
                    var cells = map.TerrainGridSystem.CellGetNeighboursWithinRange(cellIndex, minSteps, maxSteps,
                        canCrossCheckType: TGS.CanCrossCheckType.IgnoreCanCrossCheckOnAllCells);
                    foreach (var cell in cells)
                    {
                        if (!CheckCellCanSelect(cell)) continue;
                        if (!PathFinder.CanBasePass(cell, owner)) continue;
                        if (AreaManager.instance.CheckContainsMoveUnit(cell)) continue;
                        if (maxSteps > 1)
                        {
                            if (CheckPathExits(owner, cell))
                            {
                                owner.controlData.targetCellIndex = cell;
                                return;
                            }
                        }
                        else
                        {
                            owner.controlData.targetCellIndex = cell;
                            return;
                        }
                    }
                }

                // 无处可去
                owner.MoveTo(owner.transData.bornCellIndex, true);
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.MoveOtherCell error: {0}", e);
            }
        }

        /// <summary>
        /// 移动至周围可攻击格子
        /// </summary>
        private static void MoveOtherCanAttackCell(GameUnit owner, GameUnit enemy, int maxDistance = 2)
        {
            try
            {
                var map = LevelManager.Instance.CurrentLevel?.Map;
                if (map == null || owner == null || enemy == null) return;
                var enemyCellIndex = enemy.transData.cellIndex;
                var cellIndex = owner.transData.cellIndex;
                if (!AreaManager.instance.CheckContainsMoveUnit(cellIndex))
                    return;
                for (var i = 1; i <= maxDistance; i++)
                {
                    var minSteps = i - 1;
                    var maxSteps = i;
                    var cells = map.TerrainGridSystem.CellGetNeighboursWithinRange(cellIndex, minSteps, maxSteps,
                        canCrossCheckType: TGS.CanCrossCheckType.IgnoreCanCrossCheckOnAllCells);
                    foreach (var cell in cells)
                    {
                        if (!CheckCellCanSelect(cell)) continue;
                        if (!PathFinder.CanBasePass(cell, owner)) continue;
                        if (AreaManager.instance.CheckContainsMoveUnit(cell)) continue;
                        // 判断该位置可否攻击目标
                        var searchArea = AreaManager.instance.attackAreaManager.GetAttackArea(cell,
                            owner.fightData.attackDistance);
                        if (!searchArea.canAttackCells.Contains(enemyCellIndex)) continue;
                        if (maxSteps > 1)
                        {
                            if (CheckPathExits(owner, cell))
                            {
                                owner.controlData.targetCellIndex = cell;
                                return;
                            }
                        }
                        else
                        {
                            owner.controlData.targetCellIndex = cell;
                            return;
                        }
                    }
                }

                // 无处可去
                owner.MoveTo(owner.transData.bornCellIndex, true);
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.AvoidEnemy error: {0}", e);
            }
        }

        /// <summary>
        /// 计算当前位置与出生点位置是否超过防守距离
        /// </summary>
        public static bool CheckDistanceIsOver(GameUnit owner)
        {
            try
            {
                if (owner == null) return true;
                var map = LevelManager.Instance.CurrentLevel.Map;
                if (map == null) return true;
                var curPos = owner.transData.cellIndex;
                var bornPos = owner.unitLevelData.BornPosition;
                var distance = MapUtils.Distance(map, curPos, bornPos);
                return owner.unitLevelData.DefensiveDistance < distance;
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.CheckDistanceIsOver error: {0}", e);
                // 默认超出
                return true;
            }
        }

        /// <summary>
        /// 顺时针获取周围第一个能够到达的一圈格子
        /// </summary>
        public static int GetCanReachCellAround(Map map, GameUnit owner, int centerIndex, int step = 1)
        {
            var cellList = GetAroundCells(centerIndex, step);
            foreach (var cellIndex in cellList)
            {
                var blockData = map.GetBlockData(cellIndex);
                if (blockData == null) continue;
                var typeProperty = blockData.GetTerrainTypeProperty();
                if (typeProperty == null) continue;
                if (CheckPathExits(owner, cellIndex))
                {
                    return cellIndex;
                }
            }

            return -1;
        }

        /// <summary>
        /// 检查该点是否能通过
        /// </summary>
        /// <returns></returns>
        public static bool CheckCellCanPass(GameUnit owner, int cellIndex)
        {
            return PathFinder.CanPass(cellIndex, owner);
        }

        /// <summary>
        /// 检测是否存在路径
        /// </summary>
        public static bool CheckPathExits(GameUnit owner, int cellIndex)
        {
            var map = LevelManager.Instance.CurrentLevel.Map;
            if (owner == null || cellIndex == -1 || map == null) return false;
            var path = PathFinder.FindPath(map, cellIndex, owner);
            return path != null && path.Count > 0;
        }

        /// <summary>
        /// 设置cellIndex周围的通行级别
        /// </summary>
        /// <returns>Dic(格子,原来的通行级别)</returns>
        public static Dictionary<int, int> SetCellCrossLevel(Map map, GameUnit owner, int cellIndex, int step = 1)
        {
            if (map == null || owner == null) return null;
            var cells = new Dictionary<int, int>();
            var cellList = GetAroundCells(cellIndex, step);
            var crossLevel = owner.commonData.crossLevel + 1;
            foreach (var cell in cellList)
            {
                var blockData = map.GetBlockData(cell);
                if (blockData == null) continue;
                map.GetRuntimeBlockProperty(cell, out var data);
                var oldCrossLevel = data.crossLevel;
                if (data.crossLevel > crossLevel) continue;
                data.crossLevel = crossLevel + 1;
                map.SetRuntimeBlockProperty(cell, data);
                cells[cell] = oldCrossLevel;
                //DebugUtil.LogWarning("设置地格{0}的通行级别为:{1}", cell, crossLevel);
            }

            return cells;
        }

        /// <summary>
        /// 设置cellList通行级别
        /// </summary>
        public static void SetCellCrossLevel(Map map, Dictionary<int, int> cells)
        {
            if (map == null) return;
            foreach (var cell in cells)
            {
                var blockData = map.GetBlockData(cell.Key);
                if (blockData == null) continue;
                map.GetRuntimeBlockProperty(cell.Key, out var data);
                data.crossLevel = cell.Value;
                map.SetRuntimeBlockProperty(cell.Key, data);
                //DebugUtil.LogError("还原格子:{0}到{1}", cell.Key, cell.Value);
            }
        }

        /// <summary>
        /// 检测地格是否可选
        /// </summary>
        private static bool CheckCellCanSelect(int cellIndex)
        {
            var map = LevelManager.Instance.CurrentLevel.Map;
            if (map == null) return false;
            return MapUtils.GetTypeProperty(map, cellIndex) != null &&
                   MapUtils.GetTypeProperty(map, cellIndex).selectable;
        }

        /// <summary>
        /// 获得周围格子
        /// </summary>
        private static List<int> GetAroundCells(int centerIndex, int step = 1)
        {
            var cellList = new List<int>();
            AroundHelper.GetAround(centerIndex, step, cellList);
            return cellList;
        }

        /// <summary>
        /// 寻找锁敌范围内的敌方npc
        /// </summary>
        private static Dictionary<GameUnit, int> FindEnemyNpcInSight(GameUnit owner)
        {
            try
            {
                var enemyNpc = new Dictionary<GameUnit, int>();
                var level = LevelManager.Instance.CurrentLevel;
                if (level == null) return enemyNpc;
                var map = LevelManager.Instance.CurrentLevel.Map;
                if (map == null || level.SelfNpcLocalID == null || level.SelfNpcLocalID.Count <= 0) return enemyNpc;
                var enemyList = new List<GameUnit>();
                GameUnitManager.instance.characterManager.SearchEnemies(owner, enemyList);
                foreach (var enemy in enemyList)
                {
                    if (enemy.unitLevelData == null) continue;
                    if (level.SelfNpcLocalID.Contains(enemy.unitLevelData.LocalId))
                    {
                        var distance = MapUtils.Distance(map, enemy.transData.cellIndex, owner.transData.cellIndex);
                        if (distance <= owner.fightData.findEnemyRange)
                            enemyNpc.Add(enemy, distance);
                    }
                }

                return enemyNpc;
            }
            catch (Exception e)
            {
                DebugUtil.LogError("AIUtils.FindEnemyNpcInSight error: {0}", e);
                return null;
            }
        }
    }
}