using System;
using System.Collections.Generic;
using UniRx;
using UnityEngine;
using SLSUtilities.General;

namespace Cielonos.MainGame.Characters
{
    /// <summary>
    /// 选择依赖角色的哪一层时间倍率。
    /// </summary>
    public enum CreatorTimePolicy
    {
        CreatorFullTime,
        CreatorWithoutLocalTime,
        GlobalTime
    }

    public partial class CharacterBase
    {
    public partial class SelfTimeSubmodule : SubmoduleBase<CharacterBase>
    {
        private TimeManager timeManager => TimeManager.Instance;
        public IObservable<float> timeScaleObservable { get; private set; }
        
        public FloatReactiveProperty localTimeScale;
        private float globalTimeScale => timeManager.globalTimeScale.Value;
        private float playerTimeScale => timeManager.playerTimeScale.Value;
        private float alliedMinionTimeScale => timeManager.alliedMinionTimeScale.Value;
        private float enemyTimeScale => timeManager.enemyTimeScale.Value;
        private float nonPlayerTimeScale => timeManager.nonPlayerTimeScale.Value;
        
        public Dictionary<string, CooldownTimer> coolDownTimers = new Dictionary<string, CooldownTimer>();
        
        /// <summary>
        /// 不包含角色 localTimeScale 的时间倍率。
        /// 用于已经发射、应独立于发射者局部暂停的 AttackArea，同时仍受群体与全局时间效果影响。
        /// </summary>
        public float TimeScaleWithoutLocal => owner.fraction switch
        {
            Fraction.Player => globalTimeScale * playerTimeScale,
            Fraction.AlliedMinion => globalTimeScale * alliedMinionTimeScale * nonPlayerTimeScale,
            Fraction.Enemy => globalTimeScale * enemyTimeScale * nonPlayerTimeScale,
            Fraction.Neutral => globalTimeScale * nonPlayerTimeScale,
            _ => globalTimeScale
        };

        public float TimeScale => localTimeScale.Value * TimeScaleWithoutLocal;
        public float DeltaTimeWithoutLocal => Time.deltaTime * TimeScaleWithoutLocal;
        public float DeltaTime => Time.deltaTime * TimeScale;

        /// <summary>
        /// 按指定策略取得时间倍率，供 AttackArea、VFX 等由角色创建的独立对象使用。
        /// </summary>
        public float GetTimeScale(CreatorTimePolicy policy)
        {
            return policy switch
            {
                CreatorTimePolicy.CreatorFullTime => TimeScale,
                CreatorTimePolicy.CreatorWithoutLocalTime => TimeScaleWithoutLocal,
                CreatorTimePolicy.GlobalTime => 1f,
                _ => throw new ArgumentOutOfRangeException(nameof(policy), policy, null)
            };
        }

        public float GetDeltaTime(CreatorTimePolicy policy)
        {
            return Time.deltaTime * GetTimeScale(policy);
        }

        public SelfTimeSubmodule(CharacterBase entity) : base(entity)
        {
            localTimeScale = new FloatReactiveProperty(1);
            
            switch (owner.fraction)
            {
                case Fraction.Player:
                    // 依赖: local, global, player
                    timeScaleObservable = 
                        localTimeScale.CombineLatest(
                        timeManager.globalTimeScale, 
                        timeManager.playerTimeScale,
                        (local, global, player) => local * global * player
                    );
                    break;

                case Fraction.AlliedMinion:
                    // 依赖: local, global, alliedMinion, nonPlayer
                    timeScaleObservable = 
                        localTimeScale.CombineLatest(
                        timeManager.globalTimeScale, 
                        timeManager.alliedMinionTimeScale,
                        timeManager.nonPlayerTimeScale,
                        (local, global, minion, nonPlayer) => local * global * minion * nonPlayer
                    );
                    break;

                case Fraction.Enemy:
                    // 依赖: local, global, enemy, nonPlayer
                    timeScaleObservable = 
                        localTimeScale.CombineLatest(
                        timeManager.globalTimeScale, 
                        timeManager.enemyTimeScale,
                        timeManager.nonPlayerTimeScale,
                        (local, global, enemy, nonPlayer) => local * global * enemy * nonPlayer
                    );
                    break;

                case Fraction.Neutral:
                    // 依赖: local, global, nonPlayer
                    timeScaleObservable = 
                        localTimeScale.CombineLatest(
                        timeManager.globalTimeScale, 
                        timeManager.nonPlayerTimeScale,
                        (local, global, nonPlayer) => local * global * nonPlayer
                    );
                    break;
                
                default:
                    throw new ArgumentOutOfRangeException();
            }
        }

        public void SetUp(CharacterBase entity)
        {

            if (entity.animationSc.animator != null)
            {
                timeScaleObservable.Subscribe(timeScale =>
                {
                    entity.animationSc.animator.speed = timeScale;
                }).AddTo(entity);
            }
        }

        public void Update()
        {
            // 这里不需要每帧计算 TimeScale，因为它是通过 ReactiveProperty 自动更新的
            // 但是我们需要更新所有 Timer 的 currentTime
            foreach (var timer in coolDownTimers.Values)
            {
                timer.Update(DeltaTime);
            }
        }
    }

    public partial class SelfTimeSubmodule
    {
        /// <summary>
        /// 添加一个基于本地时间（Local DeltaTime）的计时器
        /// </summary>
        public IDisposable AddLocalTimer(float duration, Action onComplete, Action onUpdate = null)
        {
            // 用于记录累积时间
            float accumulatedTime = 0f;

            return Observable.EveryUpdate()
                .Select(_ => DeltaTime) // 1. 获取每帧的真实 DeltaTime
                .TakeWhile(dt => 
                {
                    // 2. 累加时间
                    accumulatedTime += dt;
                    // 3. 如果累积时间小于总时长，继续流；否则停止流并触发 OnCompleted
                    return accumulatedTime < duration;
                })
                .Subscribe(
                    _ => onUpdate?.Invoke(), // 每帧更新时执行 Action
                    () => onComplete?.Invoke() // 4. 流结束时（TakeWhile 返回 false）执行 Action
                ).AddTo(owner); // 5. 绑定生命周期到角色，防止内存泄漏
        }
        
        public IDisposable AddGlobalTimer(float duration, Action onComplete, Action onUpdate = null)
        {
            // 用于记录累积时间
            float accumulatedTime = 0f;

            return Observable.EveryUpdate()
                .Select(_ => Time.deltaTime) // 1. 获取每帧的全局 DeltaTime
                .TakeWhile(dt => 
                {
                    // 2. 累加时间
                    accumulatedTime += dt;
                    // 3. 如果累积时间小于总时长，继续流；否则停止流并触发 OnCompleted
                    return accumulatedTime < duration;
                })
                .Subscribe(
                    _ => onUpdate?.Invoke(), // 每帧更新时执行 Action
                    () => onComplete?.Invoke() // 4. 流结束时（TakeWhile 返回 false）执行 Action
                ).AddTo(owner); // 5. 绑定生命周期到角色，防止内存泄漏
        }
    }
    
    public partial class SelfTimeSubmodule
    {
        // 缓存一个默认的抛物线曲线，避免每次 null 时都 new 一个
        // 形状：(0,0) -> (0.5, 1) -> (1, 0)
        private static readonly AnimationCurve DefaultParabola = new AnimationCurve(
            new Keyframe(0f, 0f), 
            new Keyframe(0.5f, 1f), 
            new Keyframe(1f, 0f)
        );
        
        private IDisposable hitStopDisposable;
        
        /// <summary>
        /// 应用顿帧（Hit Stop）
        /// </summary>
        /// <param name="duration">持续时间（秒，基于全局游戏时间）</param>
        /// <param name="targetScale">目标缩放倍率（通常为 0 或 0.1）</param>
        public void ModifyTimeScale(float duration, float targetScale = 0f)
        {
            // 1. 如果之前有正在进行的顿帧，先取消它（防止旧的恢复逻辑覆盖新的设置）
            hitStopDisposable?.Dispose();

            // 2. 设置当前的缩放倍率
            localTimeScale.Value = targetScale;

            // 3. 开启计时器
            // 注意：这里使用 Scheduler.MainThread，它是基于 Time.time (全局时间) 的。
            // 这意味着：
            // - 它会受到 Time.timeScale (全局暂停) 的影响（符合预期，游戏暂停时顿帧也该暂停）。
            // - 它 *不会* 受到 timeScaleCoefficient (我们自己改的本地时间) 的影响（关键！）。
            hitStopDisposable = Observable.Timer(TimeSpan.FromSeconds(duration), Scheduler.MainThread)
                .Subscribe(_ => 
                {
                    // 计时结束，恢复为 1
                    localTimeScale.Value = 1f;
                    hitStopDisposable = null;
                })
                .AddTo(owner); // 安全性：如果角色在顿帧期间死亡/销毁，自动取消计时器
        }

        /// <summary>
        /// 使用曲线动态修改本地时间流速
        /// </summary>
        /// <param name="duration">持续时间（秒）</param>
        /// <param name="zeroValue">曲线起点值</param>
        /// <param name="oneValue">曲线终点值</param>
        /// <param name="easeType">插值曲线（null 则使用默认的 EaseInOut (从0到1) 曲线）</param>
        public void ModifyTimeScale(float duration, EaseType easeType, float zeroValue = 0, float oneValue = 1)
        {
            // 1. 清理旧的计时器
            hitStopDisposable?.Dispose();
            
            AnimationCurve curve = Ease.GetCurve(easeType);
            
            // 3. 记录开始时的累计时间
            float timer = 0f;

            // 4. 开启每帧更新的流
            hitStopDisposable = Observable.EveryUpdate()
                .TakeWhile(_ => timer < duration) // 当时间超过 duration 时结束流
                .Subscribe(
                    _ =>
                    {
                        // 累加时间
                        timer += DeltaTime;

                        // 计算归一化时间（0 到 1）
                        float normalizedTime = Mathf.Clamp01(timer / duration);

                        // 根据曲线获取当前的插值系数
                        float curveValue = curve.Evaluate(normalizedTime);

                        // 计算当前的时间缩放值
                        float currentScale = curveValue * (oneValue - zeroValue) + zeroValue;

                        // 应用到 timeScaleCoefficient
                        localTimeScale.Value = currentScale;
                    },
                    () =>
                    {
                        // 5. 计时结束后的收尾工作
                        // 通常为了安全，结束后我们会强制恢复到 1.0 (正常速度)
                        // 或者你可以恢复到 start，视具体需求而定
                        localTimeScale.Value = 1f;
                        hitStopDisposable = null;
                    }
                )
                .AddTo(owner); // 绑定生命周期
        }

        // 可选：提供一个强制恢复的方法，用于因为某些逻辑需要立刻打断顿帧时调用
        public void ResetTimeScale()
        {
            hitStopDisposable?.Dispose();
            localTimeScale.Value = 1f;
        }
    }

    public class CooldownTimer : Timer
    {
        public float originalDuration; // 可选：记录最初设置的持续时间，方便重置时使用
        
        public CooldownTimer(float duration) : base(duration)
        {
            this.originalDuration = duration;
        }
        
        /// <summary>
        /// 重置计时器，可以选择新的持续时间（如果不提供则使用原始持续时间）
        /// </summary>
        /// <param name="newDuration"></param>
        public override void Reset(float newDuration = -1f)
        {
            isCompleted = false;
            currentTime = 0f;
            duration = newDuration >= 0f ? newDuration : originalDuration;
        }
    }
    }
}