using System.Text;
using Milimoe.FunGame.Core.Api.Utility;
using Milimoe.FunGame.Core.Interface.Base;
using Milimoe.FunGame.Core.Interface.Entity;
using Milimoe.FunGame.Core.Library.Constant;

namespace Milimoe.FunGame.Core.Entity
{
    /// <summary>
    /// 与 <see cref="Character"/> 不同，构造技能时，建议继承此类再构造
    /// </summary>
    public class Skill : BaseEntity, ISkill, IActiveEnable
    {
        /// <summary>
        /// 唯一标识符 [ 只有物品技能需要赋值，用于表示与其关联的物品：<see cref="Item.Guid"/> ]
        /// <para>其他情况请保持此属性为 <see cref="Guid.Empty"/></para>
        /// </summary>
        public override Guid Guid { get; set; } = Guid.Empty;

        /// <summary>
        /// 此技能所属的角色
        /// </summary>
        public Character? Character { get; set; } = null;

        /// <summary>
        /// 技能描述
        /// </summary>
        public virtual string Description { get; set; } = "";

        /// <summary>
        /// 技能的通用描述
        /// </summary>
        public virtual string GeneralDescription { get; set; } = "";

        /// <summary>
        /// 驱散性和被驱散性的描述
        /// </summary>
        public virtual string DispelDescription { get; set; } = "";

        /// <summary>
        /// 释放技能时的口号
        /// </summary>
        public virtual string Slogan { get; set; } = "";

        /// <summary>
        /// 技能等级，等于 0 时可以称之为尚未学习
        /// </summary>
        public int Level
        {
            get
            {
                return Math.Max(0, _Level);
            }
            set
            {
                int max = SkillSet.GetSkillMaxLevel(SkillType, GameplayEquilibriumConstant);
                _Level = Math.Min(Math.Max(0, value), max);
                OnLevelUp();
            }
        }

        /// <summary>
        /// 技能类型 [ 此项为最高优先级 ]
        /// </summary>
        [InitRequired]
        public SkillType SkillType { get; set; } = SkillType.Passive;

        /// <summary>
        /// 是否是主动技能 [ 此项为高优先级 ]
        /// </summary>
        public bool IsActive => SkillType != SkillType.Passive;

        /// <summary>
        /// 是否可用 [ 此项为高优先级 ]
        /// </summary>
        public bool Enable { get; set; } = true;

        /// <summary>
        /// 效果持续生效中 [ 此项为高优先级 ] [ 此项设置为true后不允许再次释放，防止重复释放 ]
        /// </summary>
        public bool IsInEffect { get; set; } = false;

        /// <summary>
        /// 是否是爆发技 [ 此项为高优先级 ]
        /// </summary>
        public bool IsSuperSkill => SkillType == SkillType.SuperSkill;

        /// <summary>
        /// 是否属于魔法 [ <see cref="IsActive"/> 必须为 true ]，反之为战技
        /// </summary>
        public bool IsMagic => SkillType == SkillType.Magic;

        /// <summary>
        /// 是否无视施法距离（全图施法），魔法默认为 true，战技默认为 false
        /// </summary>
        public bool CastAnyWhere { get; set; } = false;
        
        /// <summary>
        /// 施法距离 [ 单位：格 ]
        /// </summary>
        [InitOptional]
        public int CastRange { get; set; } = 5;

        /// <summary>
        /// 可选取自身
        /// </summary>
        public virtual bool CanSelectSelf { get; set; } = false;

        /// <summary>
        /// 可选取敌对角色
        /// </summary>
        public virtual bool CanSelectEnemy { get; set; } = true;

        /// <summary>
        /// 可选取友方角色
        /// </summary>
        public virtual bool CanSelectTeammate { get; set; } = false;

        /// <summary>
        /// 选取所有敌对角色，优先级大于 <see cref="CanSelectTargetCount"/>
        /// </summary>
        public virtual bool SelectAllEnemies { get; set; } = false;

        /// <summary>
        /// 选取所有友方角色，优先级大于 <see cref="CanSelectTargetCount"/>，默认包含自身
        /// </summary>
        public virtual bool SelectAllTeammates { get; set; } = false;

        /// <summary>
        /// 可选取的作用目标数量
        /// </summary>
        public virtual int CanSelectTargetCount { get; set; } = 1;

        /// <summary>
        /// 可选取的作用范围 [ 单位：格 ]
        /// </summary>
        public virtual int CanSelectTargetRange { get; set; } = 0;

        /// <summary>
        /// 选取角色的条件
        /// </summary>
        public List<Func<Character, bool>> SelectTargetPredicates { get; } = [];

        /// <summary>
        /// 实际魔法消耗 [ 魔法 ]
        /// </summary>
        public double RealMPCost => Math.Max(0, MPCost * (1 - Calculation.PercentageCheck((Character?.INT ?? 0) * GameplayEquilibriumConstant.INTtoCastMPReduce)));

        /// <summary>
        /// 魔法消耗 [ 魔法 ]
        /// </summary>
        [InitOptional]
        public virtual double MPCost { get; set; } = 0;

        /// <summary>
        /// 吟唱时间 [ 魔法 ]
        /// </summary>
        [InitOptional]
        public virtual double CastTime { get; set; } = 0;

        /// <summary>
        /// 实际吟唱时间 [ 魔法 ]
        /// </summary>
        public double RealCastTime => Math.Max(0, CastTime * (1 - Calculation.PercentageCheck(Character?.AccelerationCoefficient ?? 0)));

        /// <summary>
        /// 实际能量消耗 [ 战技 ]
        /// </summary>
        public double RealEPCost => CostAllEP ? Math.Max(MinCostEP, Character?.EP ?? MinCostEP) : (IsSuperSkill ? EPCost : Math.Max(0, EPCost * (1 - Calculation.PercentageCheck((Character?.INT ?? 0) * GameplayEquilibriumConstant.INTtoCastEPReduce))));

        /// <summary>
        /// 能量消耗 [ 战技 ]
        /// </summary>
        [InitOptional]
        public virtual double EPCost { get; set; } = 0;

        /// <summary>
        /// 消耗所有能量 [ 战技 ]
        /// </summary>
        public virtual bool CostAllEP { get; set; } = false;

        /// <summary>
        /// 消耗所有能量的最小能量限制 [ 战技 ] 默认值：100
        /// </summary>
        public virtual double MinCostEP { get; set; } = 100;

        /// <summary>
        /// 上一次释放此技能消耗的魔法 [ 魔法 ]
        /// </summary>
        public double LastCostMP { get; set; } = 0;

        /// <summary>
        /// 上一次释放此技能消耗的能量 [ 战技 ]
        /// </summary>
        public double LastCostEP { get; set; } = 0;

        /// <summary>
        /// 实际冷却时间
        /// </summary>
        public double RealCD => Math.Max(0, CD * (1 - (Character?.CDR ?? 0)));

        /// <summary>
        /// 冷却时间
        /// </summary>
        [InitRequired]
        public virtual double CD { get; set; } = 0;

        /// <summary>
        /// 剩余冷却时间 [ 建议配合 <see cref="Enable"/>  属性使用 ]
        /// </summary>
        public double CurrentCD { get; set; } = 0;

        /// <summary>
        /// 硬直时间
        /// </summary>
        [InitRequired]
        public virtual double HardnessTime { get; set; } = 0;

        /// <summary>
        /// 额外硬直时间 [ 技能和物品相关 ]
        /// </summary>
        public double ExHardnessTime { get; set; } = 0;

        /// <summary>
        /// 额外硬直时间% [ 技能和物品相关 ]
        /// </summary>
        public double ExHardnessTime2 { get; set; } = 0;

        /// <summary>
        /// 实际硬直时间
        /// </summary>
        public double RealHardnessTime => Math.Max(0, (HardnessTime + ExHardnessTime) * (1 + ExHardnessTime2) * (1 - Calculation.PercentageCheck(Character?.ActionCoefficient ?? 0)));

        /// <summary>
        /// 效果列表
        /// </summary>
        public HashSet<Effect> Effects { get; } = [];

        /// <summary>
        /// 用于动态扩展技能的参数
        /// </summary>
        public Dictionary<string, object> Values { get; } = [];

        /// <summary>
        /// 游戏中的行动顺序表实例，在技能效果被触发时，此实例会获得赋值，使用时需要判断其是否存在
        /// </summary>
        public IGamingQueue? GamingQueue { get; set; } = null;

        /// <summary>
        /// 技能是否属于某个物品
        /// </summary>
        public Item? Item { get; set; } = null;

        /// <summary>
        /// 继承此类实现时，调用基类的构造函数
        /// </summary>
        /// <param name="type"></param>
        /// <param name="character"></param>
        protected Skill(SkillType type, Character? character = null)
        {
            SkillType = type;
            CastAnyWhere = SkillType == SkillType.Magic;
            Character = character;
        }

        /// <summary>
        /// 用于构造 JSON
        /// </summary>
        internal Skill() { }

        /// <summary>
        /// 设置一些属性给从工厂构造出来的 <paramref name="newbyFactory"/> 对象
        /// </summary>
        /// <param name="newbyFactory"></param>
        public void SetPropertyToItemModuleNew(Skill newbyFactory)
        {
            newbyFactory.GamingQueue = GamingQueue;
            newbyFactory.Enable = Enable;
            newbyFactory.IsInEffect = IsInEffect;
            newbyFactory.CurrentCD = CurrentCD;
        }

        /// <summary>
        /// 触发技能升级
        /// </summary>
        public void OnLevelUp()
        {
            if (!IsActive && Level > 0)
            {
                foreach (Effect e in AddPassiveEffectToCharacter())
                {
                    e.GamingQueue = GamingQueue;
                    if (Character != null && !Character.Effects.Contains(e))
                    {
                        Character.Effects.Add(e);
                        e.OnEffectGained(Character);
                    }
                }
            }
            if (Level > 0 && Character != null)
            {
                Effect[] effects = [.. Character.Effects.Where(e => e.IsInEffect)];
                foreach (Effect e in effects)
                {
                    e.OnSkillLevelUp(Character, Level);
                }
            }
        }

        /// <summary>
        /// 当获得技能时
        /// </summary>
        /// <param name="queue"></param>
        public void OnSkillGained(IGamingQueue queue)
        {
            GamingQueue = queue;
            OnLevelUp();
        }

        /// <summary>
        /// 在技能持有者的回合开始前
        /// </summary>
        /// <param name="character"></param>
        /// <param name="enemys"></param>
        /// <param name="teammates"></param>
        /// <param name="skills"></param>
        /// <param name="items"></param>
        public virtual void OnTurnStart(Character character, List<Character> enemys, List<Character> teammates, List<Skill> skills, List<Item> items)
        {

        }

        /// <summary>
        /// 获取可选择的目标列表
        /// </summary>
        /// <param name="caster"></param>
        /// <param name="enemys"></param>
        /// <param name="teammates"></param>
        /// <returns></returns>
        public virtual List<Character> GetSelectableTargets(Character caster, List<Character> enemys, List<Character> teammates)
        {
            List<Character> selectable = [];

            if (CanSelectSelf)
            {
                selectable.Add(caster);
            }

            ImmuneType checkType = ImmuneType.Skilled | ImmuneType.All;
            if (IsMagic)
            {
                checkType |= ImmuneType.Magical;
            }

            foreach (Character character in enemys)
            {
                IEnumerable<Effect> effects = character.Effects.Where(e => e.IsInEffect);
                if (CanSelectEnemy && ((character.ImmuneType & checkType) == ImmuneType.None ||
                    effects.Any(e => e.IgnoreImmune == ImmuneType.All || e.IgnoreImmune == ImmuneType.Skilled || (IsMagic && e.IgnoreImmune == ImmuneType.Magical))))
                {
                    selectable.Add(character);
                }
            }
            
            foreach (Character character in teammates)
            {
                IEnumerable<Effect> effects = character.Effects.Where(e => e.IsInEffect);
                if (CanSelectTeammate && ((character.ImmuneType & checkType) == ImmuneType.None ||
                    effects.Any(e => e.IgnoreImmune == ImmuneType.All || e.IgnoreImmune == ImmuneType.Skilled || (IsMagic && e.IgnoreImmune == ImmuneType.Magical))))
                {
                    selectable.Add(character);
                }
            }

            // 其他条件
            selectable = [.. selectable.Where(c => SelectTargetPredicates.All(f => f(c)))];

            return selectable;
        }

        /// <summary>
        /// 选取技能目标
        /// </summary>
        /// <param name="caster"></param>
        /// <param name="enemys"></param>
        /// <param name="teammates"></param>
        /// <returns></returns>
        public virtual List<Character> SelectTargets(Character caster, List<Character> enemys, List<Character> teammates)
        {
            List<Character> tobeSelected = GetSelectableTargets(caster, enemys, teammates);

            List<Character> targets = [];

            if (SelectAllTeammates || SelectAllEnemies)
            {
                if (SelectAllTeammates)
                {
                    targets.AddRange(tobeSelected.Where(c => c == caster || teammates.Contains(c)));
                }
                if (SelectAllEnemies)
                {
                    targets.AddRange(tobeSelected.Where(enemys.Contains));
                }
            }
            else if (tobeSelected.Count <= CanSelectTargetCount)
            {
                targets.AddRange(tobeSelected);
            }
            else
            {
                targets.AddRange(tobeSelected.OrderBy(x => Random.Shared.Next()).Take(CanSelectTargetCount));
            }

            return [.. targets.Distinct()];
        }

        /// <summary>
        /// 技能开始吟唱时 [ 吟唱魔法、释放战技和爆发技、预释放爆发技均可触发 ]
        /// </summary>
        /// <param name="queue"></param>
        /// <param name="caster"></param>
        /// <param name="targets"></param>
        public void OnSkillCasting(IGamingQueue queue, Character caster, List<Character> targets)
        {
            GamingQueue = queue;
            foreach (Effect e in Effects)
            {
                e.GamingQueue = GamingQueue;
                e.OnSkillCasting(caster, targets);
            }
        }

        /// <summary>
        /// 技能效果触发前
        /// </summary>
        public void BeforeSkillCasted()
        {
            LastCostMP = RealMPCost;
            LastCostEP = RealEPCost;
        }

        /// <summary>
        /// 触发技能效果 [ 局内版 ]
        /// </summary>
        /// <param name="queue"></param>
        /// <param name="caster"></param>
        /// <param name="targets"></param>
        public void OnSkillCasted(IGamingQueue queue, Character caster, List<Character> targets)
        {
            GamingQueue = queue;
            foreach (Effect e in Effects)
            {
                e.GamingQueue = GamingQueue;
                e.OnSkillCasted(caster, targets, Values);
            }
        }

        /// <summary>
        /// 对目标触发技能效果
        /// </summary>
        /// <param name="user"></param>
        /// <param name="targets"></param>
        public void OnSkillCasted(User user, List<Character> targets)
        {
            foreach (Effect e in Effects)
            {
                e.OnSkillCasted(user, targets, Values);
            }
        }

        /// <summary>
        /// 检查角色是否在 AI 控制状态
        /// </summary>
        /// <param name="character"></param>
        /// <returns></returns>
        public bool IsCharacterInAIControlling(Character character)
        {
            return GamingQueue?.IsCharacterInAIControlling(character) ?? false;
        }

        /// <summary>
        /// 被动技能，需要重写此方法，返回被动特效给角色 [ 此方法会在技能学习时触发 ]
        /// </summary>
        /// <returns></returns>
        public virtual IEnumerable<Effect> AddPassiveEffectToCharacter()
        {
            return [];
        }

        /// <summary>
        /// 返回技能的详细说明
        /// </summary>
        /// <param name="showOriginal"></param>
        /// <param name="showCD"></param>
        /// <param name="showHardness"></param>
        /// <returns></returns>
        public string GetInfo(bool showOriginal = false, bool showCD = true, bool showHardness = true)
        {
            StringBuilder builder = new();

            string type = IsSuperSkill ? "【爆发技】" : (IsMagic ? "【魔法】" : (IsActive ? "【主动】" : "【被动】"));
            string level = Level > 0 ? " - 等级 " + Level : " - 尚未学习";
            builder.AppendLine(type + Name + level);
            builder.AppendLine("技能描述：" + (Level == 0 && GeneralDescription.Trim() != "" ? GeneralDescription : Description));
            if (CurrentCD > 0)
            {
                builder.AppendLine($"正在冷却：剩余 {CurrentCD:0.##} {GameplayEquilibriumConstant.InGameTime}");
            }
            if (!Enable)
            {
                builder.AppendLine("技能当前不可用");
            }
            if (IsInEffect)
            {
                builder.AppendLine("效果结束前不可用");
            }
            if (DispelDescription != "")
            {
                builder.AppendLine($"{DispelDescription}");
            }
            if (IsActive && (Item?.IsInGameItem ?? true))
            {
                if (SkillType == SkillType.Item)
                {
                    if (RealMPCost > 0)
                    {
                        builder.AppendLine($"魔法消耗：{RealMPCost:0.##}{(showOriginal && RealMPCost != MPCost ? $"（原始值：{MPCost:0.##}）" : "")}");
                    }
                    if (RealEPCost > 0)
                    {
                        builder.AppendLine($"能量消耗：{RealEPCost:0.##}{(showOriginal && RealEPCost != EPCost ? $"（原始值：{EPCost:0.##}）" : "")}");
                    }
                }
                else
                {
                    if (IsSuperSkill)
                    {
                        builder.AppendLine($"能量消耗：{RealEPCost:0.##}{(showOriginal && RealEPCost != EPCost ? $"（原始值：{EPCost:0.##}）" : "")}");
                    }
                    else
                    {
                        if (IsMagic)
                        {
                            builder.AppendLine($"魔法消耗：{RealMPCost:0.##}{(showOriginal && RealMPCost != MPCost ? $"（原始值：{MPCost:0.##}）" : "")}");
                            builder.AppendLine($"吟唱时间：{RealCastTime:0.##}{(showOriginal && RealCastTime != CastTime ? $"（原始值：{CastTime:0.##}）" : "")}");
                        }
                        else
                        {
                            builder.AppendLine($"能量消耗：{RealEPCost:0.##}{(showOriginal && RealEPCost != EPCost ? $"（原始值：{EPCost:0.##}）" : "")}");
                        }
                    }
                }
                if (showCD && CD > 0)
                {
                    builder.AppendLine($"冷却时间：{RealCD:0.##}{(showOriginal && RealCD != CD ? $"（原始值：{CD:0.##}）" : "")}");
                }
                if (showHardness && HardnessTime > 0)
                {
                    builder.AppendLine($"硬直时间：{RealHardnessTime:0.##}{(showOriginal && RealHardnessTime != HardnessTime ? $"（原始值：{HardnessTime:0.##}）" : "")}");
                }
            }

            return builder.ToString();
        }

        /// <summary>
        /// 返回技能的详细说明
        /// </summary>
        /// <returns></returns>
        public override string ToString() => GetInfo(true);

        /// <summary>
        /// 返回技能的详细说明，有选项
        /// </summary>
        /// <param name="showOriginal"></param>
        /// <param name="showCD"></param>
        /// <param name="showHardness"></param>
        /// <returns></returns>
        public string ToString(bool showOriginal, bool showCD, bool showHardness)
        {
            return GetInfo(showOriginal, showCD, showHardness);
        }

        /// <summary>
        /// 判断两个技能是否相同 检查Id.Name
        /// </summary>
        /// <param name="other"></param>
        /// <returns></returns>
        public override bool Equals(IBaseEntity? other)
        {
            return other is Skill c && c.Id + "." + c.Name == Id + "." + Name;
        }

        /// <summary>
        /// 复制一个技能
        /// </summary>
        /// <returns></returns>
        public Skill Copy(bool copyProperty = true, IEnumerable<Skill>? skillsDefined = null)
        {
            Dictionary<string, object> args = new()
            {
                { "values", Values }
            };
            Skill? skillDefined = null;
            if (skillsDefined != null && skillsDefined.FirstOrDefault(i => i.GetIdName() == GetIdName()) is Skill temp)
            {
                skillDefined = temp;
            }
            if (skillDefined != null)
            {
                args["values"] = skillDefined.Values;
            }
            Skill skill = Factory.OpenFactory.GetInstance<Skill>(Id, Name, args);
            skillDefined ??= this;
            if (copyProperty) SetPropertyToItemModuleNew(skill);
            skill.Id = skillDefined.Id;
            skill.Name = skillDefined.Name;
            skill.Description = skillDefined.Description;
            skill.GeneralDescription = skillDefined.GeneralDescription;
            skill.DispelDescription = skillDefined.DispelDescription;
            skill.SkillType = skillDefined.SkillType;
            skill.MPCost = skillDefined.MPCost;
            skill.CastTime = skillDefined.CastTime;
            skill.EPCost = skillDefined.EPCost;
            skill.CD = skillDefined.CD;
            skill.HardnessTime = skillDefined.HardnessTime;
            skill.GamingQueue = skillDefined.GamingQueue;
            if (skill is OpenSkill)
            {
                foreach (Effect e in skillDefined.Effects)
                {
                    // 特效没法动态扩展，必须使用编程钩子实现，因此动态扩展的技能需要使用代码定义的特效
                    Effect neweffect = e.Copy(skill, true);
                    if (skill.GamingQueue != null)
                    {
                        neweffect.GamingQueue = skill.GamingQueue;
                    }
                    skill.Effects.Add(neweffect);
                }
            }
            return skill;
        }

        /// <summary>
        /// 等级
        /// </summary>
        private int _Level = 0;
    }
}