using System;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;

namespace Continentis.MainGame
{
    public enum BuffDispelLevel
    {
        Basic = 0, //弱驱散
        Strong = 10, //强驱散
        Immune = 20, //不可驱散（死亡除外）
        Undispellable = 100 //不可驱散（包括死亡）
    }
        
    public enum BuffType
    {
        Positive,
        Negative,
        Neutral
    }
    
    public abstract partial class BuffBase<T>
    { 
        public string name;
        public string description;
        
        public BuffType buffType;
        public BuffDispelLevel dispelThreshold;

        protected virtual void Initialize(string name, string description, BuffType buffType, BuffDispelLevel dispelThreshold)
        {
            this.name = name;
            this.description = description;
            this.buffType = buffType;
            this.dispelThreshold = dispelThreshold;
        }
    }

    public partial class BuffBase<T>
    {
        protected bool FindExistingBuff<T1, T2>(out T2 existingBuff, List<T1> buffList) where T1 : BuffBase<T> where T2 : BuffBase<T>
        {
            existingBuff = null;
            
            foreach (T1 buff in buffList.Where(buff => buff.GetType() == typeof(T2)))
            {
                existingBuff = buff as T2;
                return true;
            }
            
            return false;
        }
        
        public abstract void Apply(T attached);
        
        public abstract void Remove();

        public abstract void UntriggerRemove();
        
        public virtual void Dispel(BuffDispelLevel dispelLevel)
        {
            if (CanBeDispelled(dispelLevel))
            {
                OnBuffDispel();
                Remove();
            }
        }
    }
    
    public partial class BuffBase<T>
    {
        //Buff生命周期函数

        /// <summary>
        /// Buff被尝试添加到角色时调用。
        /// </summary>
        public virtual bool OnBuffApply(out BuffBase<T> existingBuff)
        {
            throw new System.NotImplementedException(); //需要在子类中实现
        }
        
        /// <summary>
        /// Buff首次成功添加到角色后调用。在OnBuffApply完成，且返回true之后调用。
        /// 如果Buff在被添加时，发现已有同类Buff存在，则不会调用此函数。
        /// </summary>
        public virtual void OnAfterFirstApply()
        {
            
        }
        
        /// <summary>
        /// Buff被驱散（移除）时调用，在OnBuffRemove之前调用。
        /// </summary>
        public virtual void OnBuffDispel()
        {
            
        }
        
        /// <summary>
        /// Buff被正常移除时调用。在Buff生命周期结束时调用。
        /// UntriggerRemove不会调用此函数。但是此函数通常情况下绝不会被调用。
        /// </summary>
        public virtual void OnBuffRemove()
        {
            
        }
    }
    
    public partial class BuffBase<T>
    {
        /// <summary>
        /// 判断该Buff能否被指定驱散等级的驱散效果驱散。
        /// </summary>
        protected bool CanBeDispelled(BuffDispelLevel dispelLevel)
        {
            return dispelLevel >= dispelThreshold;
        }
    }
    
}