using UnityEngine;
using BaseGames.Combat;
using BaseGames.Enemies.Abilities;

namespace BaseGames.Enemies.StatusEffects
{
    /// <summary>
    /// 冻结效果：停止敌人移动，中断所有能力，降低 BT Tick 频率。
    /// 效果持续期间每帧强制停止水平移动。
    /// </summary>
    public sealed class FrozenEffect : IStatusEffect
    {
        public StatusEffectType Type     => StatusEffectType.Frozen;
        public float            Duration { get; }
        public bool             IsFinished => _elapsed >= Duration;

        private float _elapsed;

        public FrozenEffect(float duration) => Duration = duration;

        public void OnApplied(EnemyBase enemy)
        {
            _elapsed = 0f;
            enemy.Abilities?.InterruptAll(InterruptReason.ExternalRequest);
            enemy.StopMovement();
            enemy.SetAggroTickRate(false);
        }

        public void Tick(EnemyBase enemy, float deltaTime)
        {
            _elapsed += deltaTime;
            enemy.Movement?.StopHorizontal();
        }

        public void OnRemoved(EnemyBase enemy) { }
    }

    /// <summary>
    /// 睡眠效果：敌人进入休眠状态，受到任意伤害立即唤醒。
    /// 持续时间可为负值（永久，直到被击醒）。
    /// </summary>
    public sealed class SleepEffect : IStatusEffect
    {
        public StatusEffectType Type     => StatusEffectType.Sleep;
        public float            Duration { get; }
        public bool             IsFinished => _awoken || (Duration >= 0f && _elapsed >= Duration);

        private float _elapsed;
        private bool  _awoken;
        private int   _lastHP;

        public SleepEffect(float duration = -1f) => Duration = duration;

        public void OnApplied(EnemyBase enemy)
        {
            _elapsed = 0f;
            _awoken  = false;
            _lastHP  = enemy.Stats != null ? enemy.Stats.CurrentHP : int.MaxValue;
            enemy.Abilities?.InterruptAll(InterruptReason.ExternalRequest);
            enemy.StopMovement();
            enemy.SetAggroTickRate(false);
        }

        public void Tick(EnemyBase enemy, float deltaTime)
        {
            _elapsed += deltaTime;
            enemy.Movement?.StopHorizontal();

            // 受击检测：HP 减少则唤醒
            if (enemy.Stats != null && enemy.Stats.CurrentHP < _lastHP)
                _awoken = true;
            if (enemy.Stats != null)
                _lastHP = enemy.Stats.CurrentHP;
        }

        public void OnRemoved(EnemyBase enemy) { }
    }

    /// <summary>
    /// 灼烧效果：每 tickInterval 秒对敌人造成 damagePerTick 点持续伤害。
    /// 不触发霸体判定（无 DamageFlags.ForceBreak），允许受击动作打断。
    /// </summary>
    public sealed class BurningEffect : IStatusEffect
    {
        public StatusEffectType Type     => StatusEffectType.Burning;
        public float            Duration { get; }
        public bool             IsFinished => _elapsed >= Duration;

        private readonly float _damagePerTick;
        private readonly float _tickInterval;
        private float          _elapsed;
        private float          _nextTick;

        public BurningEffect(float duration, float damagePerTick, float tickInterval = 0.5f)
        {
            Duration       = duration;
            _damagePerTick = damagePerTick;
            _tickInterval  = tickInterval;
        }

        public void OnApplied(EnemyBase enemy)
        {
            _elapsed  = 0f;
            _nextTick = _tickInterval;
        }

        public void Tick(EnemyBase enemy, float deltaTime)
        {
            _elapsed += deltaTime;
            if (_elapsed >= _nextTick)
            {
                _nextTick += _tickInterval;
                var info = new DamageInfo
                {
                    RawDamage   = (int)_damagePerTick,
                    Amount      = (int)_damagePerTick,
                    FinalDamage = (int)_damagePerTick,
                    Type        = DamageType.Fire,
                    Flags       = DamageFlags.None,
                };
                enemy.TakeDamage(info);
            }
        }

        public void OnRemoved(EnemyBase enemy) { }
    }
}