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

namespace Cielonos.MainGame.Inventory.Collections
{
    /// <summary>
    /// 记忆外骨骼 / Memory Exoskeleton
    /// 记录并调校玩家的动作模式：每击杀一个敌人，获得1%攻击速度加成（叠层）。
    /// 切换主武器时，外骨骼需要重新适配，叠层归零。
    /// </summary>
    public class MemoryExoskeleton : PassiveEquipmentBase
    {
        private const string EventKey = "MemoryExoskeleton";
        private int _currentStacks;

        public override void OnObtained()
        {
            base.OnObtained();
            _currentStacks = 0;

            Action<AttackAreaBase, CharacterBase, Attack.Result> onFinishAttack = OnFinishAttack;
            player.eventSm.onFinishAttack.Add(EventKey, onFinishAttack.ToPrioritized());

            Action<MainWeaponBase> onMainWeaponChanged = OnMainWeaponChanged;
            player.eventSm.onMainWeaponChanged.Add(EventKey, onMainWeaponChanged.ToPrioritized());
        }

        public override void OnDiscarded()
        {
            player.eventSm.onMainWeaponChanged.Remove(EventKey);
            player.eventSm.onFinishAttack.Remove(EventKey);

            // 清除已施加的攻击速度加成
            if (_currentStacks > 0)
            {
                _currentStacks = 0;
                ApplyAttackSpeed(0f);
            }

            base.OnDiscarded();
        }

        /// <summary>
        /// 攻击结算完成时检查是否击杀目标，是则叠加攻击速度。
        /// </summary>
        private void OnFinishAttack(AttackAreaBase attackArea, CharacterBase target, Attack.Result result)
        {
            if (!result.causedDeath) return;

            float attackSpeedPerKill = passiveAttributeSm.GetItemAttribute("AttackSpeedPerKill");
            float maxAttackSpeed = passiveAttributeSm.GetItemAttribute("MaxAttackSpeed");
            
            _currentStacks++;
            float newAttackSpeed = _currentStacks * attackSpeedPerKill;
            newAttackSpeed = Mathf.Min(newAttackSpeed, maxAttackSpeed);
            
            ApplyAttackSpeed(newAttackSpeed);
        }

        /// <summary>
        /// 切换主武器时，外骨骼需要重新适配当前武器，叠层归零。
        /// </summary>
        private void OnMainWeaponChanged(MainWeaponBase newWeapon)
        {
            if (_currentStacks <= 0) return;

            _currentStacks = 0;
            ApplyAttackSpeed(0f);
            MainGameBaseCollection.Instance.InfoText()?.Spawn(player.centerPosition, "Exo Reset");
        }

        /// <summary>
        /// 将攻击速度加成写入属性系统并刷新。
        /// </summary>
        private void ApplyAttackSpeed(float bonus)
        {
            if (bonus > 0f)
            {
                passiveAttributeSm.charAttrNumericChange[CharacterAttribute.AttackSpeed] = bonus;
            }
            else
            {
                passiveAttributeSm.charAttrNumericChange.Remove(CharacterAttribute.AttackSpeed);
            }

            player.attributeSm.RefreshAttribute(CharacterAttribute.AttackSpeed);
        }
    }
}