using System;
using Cielonos.MainGame.Buffs;
using Cielonos.MainGame.Buffs.Character;
using Cielonos.MainGame.Characters;
using SLSUtilities.General;
using UnityEngine;

namespace Cielonos.MainGame.Inventory.Collections
{
    /// <summary>
    /// 穿甲弹头 / Armor Piercing Round
    /// Kinetics 攻击命中时降低目标护甲。
    /// </summary>
    public partial class ArmorPiercingRound : PassiveEquipmentBase
    {
        private const string EventKey = nameof(ArmorPiercingRound);
        
        public override void OnObtained()
        {
            base.OnObtained();
            Action<AttackAreaBase, CharacterBase, Attack.Context> onStartAttack = OnStartAttack;
            player.eventSm.onStartAttack.Add(EventKey, onStartAttack.ToPrioritized());
        }

        public override void OnDiscarded()
        {
            player.eventSm.onStartAttack.Remove(EventKey);
            base.OnDiscarded();
        }

        private void OnStartAttack(AttackAreaBase attackArea, CharacterBase target, Attack.Context context)
        {
            if (context.value.type == Attack.Type.Kinetics)
            {
                int armorReduction = Mathf.RoundToInt(passiveAttributeSm.GetItemAttribute("ArmorReduction"));
                new ArmorReduction(5f, armorReduction).Apply(target, player, this);
            }   
        }
    }

    public partial class ArmorPiercingRound
    {
        /// <summary>
        /// 穿甲弹头的Buff，默认降低目标等于unitedStack层数的护甲，持续5秒
        /// </summary>
        public class ArmorReduction : CharacterBuffBase
        {
            public ArmorReduction(float duration, int stack)
            {
                Initialize(BuffType.Positive, BuffDispelLevel.Basic);

                this.contentSubmodule = new ContentSubmodule(this);
                this.timeSubmodule = new TimeSubmodule(this, duration);
                this.unitedStackSubmodule = new UnitedStackSubmodule(this, stack);
                this.attributeSubmodule = new AttributeSubmodule(this);
            }

            public override bool OnBuffApply(out CharacterBuffBase existingBuff)
            {
                if (FindExistingSameBuff(out ArmorReduction existing))
                {
                    existingBuff = existing;
                    existing.timeSubmodule.RefreshDuration();
                    existing.unitedStackSubmodule.PickHigherStack(this.unitedStackSubmodule);
                    existing.UpdateArmorValue(existing.unitedStackSubmodule.stackAmount);
                    return false;
                }

                existingBuff = null;
                UpdateArmorValue(unitedStackSubmodule.stackAmount);
                return true;
            }
            
            /// <summary>
            /// 根据当前层数更新护甲加成数值。
            /// </summary>
            private void UpdateArmorValue(int stacks)
            {
                attributeSubmodule.numericChange[CharacterAttribute.Armor] = -stacks;
                attributeSubmodule.RefreshAllModifiedAttributes();
            }
        }
    }
}