using UnityEngine;
using MoreMountains.Feedbacks;
using MoreMountains.Tools;
using System.Collections.Generic;
#if MM_CINEMACHINE
using Cinemachine;
#elif MM_CINEMACHINE3
using Unity.Cinemachine;
#endif

namespace MoreMountains.FeedbacksForThirdParty
{
    // 1. 定义震动实例类 (保存单个震动的状态)
    public class MMCinemachineRotationShakeInstance
    {
        public float Duration;
        public float Timer;
        public Vector3 Amplitude;
        public AnimationCurve Curve;
        public float Intensity;
        public TimescaleModes TimescaleMode;

        public MMCinemachineRotationShakeInstance(float duration, Vector3 amplitude, AnimationCurve curve, float intensity, TimescaleModes timescaleMode)
        {
            Duration = duration;
            Timer = 0f;
            Amplitude = amplitude;
            Curve = curve;
            Intensity = intensity;
            TimescaleMode = timescaleMode;
        }
    }

    // 2. 定义事件
    public struct MMCinemachineRotationShakeEvent
    {
        static private event Delegate OnEvent;
        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)] private static void RuntimeInitialization() { OnEvent = null; }
        public static void Register(Delegate callback) { OnEvent += callback; }
        public static void Unregister(Delegate callback) { OnEvent -= callback; }

        public delegate void Delegate(MMF_Feedback source, AnimationCurve shakeCurve, float duration, Vector3 rotationAmplitude, float remapMin, float remapMax, bool relative,
            float feedbacksIntensity = 1.0f, MMChannelData channelData = null, bool resetShakerValuesAfterShake = true, bool resetTargetValuesAfterShake = true, bool forwardDirection = true, TimescaleModes timescaleMode = TimescaleModes.Scaled, bool stop = false, bool restore = false);

        public static void Trigger(MMF_Feedback source, AnimationCurve shakeCurve, float duration, Vector3 rotationAmplitude, float remapMin, float remapMax, bool relative,
            float feedbacksIntensity = 1.0f, MMChannelData channelData = null, bool resetShakerValuesAfterShake = true, bool resetTargetValuesAfterShake = true, bool forwardDirection = true, TimescaleModes timescaleMode = TimescaleModes.Scaled, bool stop = false, bool restore = false)
        {
            OnEvent?.Invoke(source, shakeCurve, duration, rotationAmplitude, remapMin, remapMax, relative, feedbacksIntensity, channelData, resetShakerValuesAfterShake, resetTargetValuesAfterShake, forwardDirection, timescaleMode, stop, restore);
        }
    }

    /// <summary>
    /// Cinemachine Rotation Shaker (Additive / Mixing Support)
    /// X/Y applied to FollowTarget, Z applied to Camera Dutch.
    /// 支持多个 Feedback 同时叠加震动。
    /// </summary>
    [AddComponentMenu("More Mountains/Feedbacks/Shakers/Cinemachine/MM Cinemachine Rotation Shaker (Additive)")]
    #if MM_CINEMACHINE
    [RequireComponent(typeof(CinemachineVirtualCamera))]
    #elif MM_CINEMACHINE3
    [RequireComponent(typeof(CinemachineCamera))]
    #endif
    public class MMCinemachineRotationShaker : MMShaker
    {
        public Transform FollowTarget => _targetCamera.Follow;

        [MMInspectorGroup("Debug Info", true, 43)]
        [MMReadOnly]
        public int ActiveShakesCount = 0;

        #if MM_CINEMACHINE
        protected CinemachineVirtualCamera _targetCamera;
        #elif MM_CINEMACHINE3
        protected CinemachineCamera _targetCamera;
        #endif

        protected float _initialDutch;
        protected Quaternion _initialTargetRotation;
        
        // 活跃震动列表
        protected List<MMCinemachineRotationShakeInstance> _activeShakes = new List<MMCinemachineRotationShakeInstance>();

        protected override void Initialization()
        {
            // 不调用 base.Initialization() 以完全接管 Update 逻辑
            #if MM_CINEMACHINE
            _targetCamera = GetComponent<CinemachineVirtualCamera>();
            #elif MM_CINEMACHINE3
            _targetCamera = GetComponent<CinemachineCamera>();
            #endif
            GrabInitialValues();
        }

        protected override void GrabInitialValues()
        {
            if (_targetCamera != null)
            {
                #if MM_CINEMACHINE
                _initialDutch = _targetCamera.m_Lens.Dutch;
                #elif MM_CINEMACHINE3
                _initialDutch = _targetCamera.Lens.Dutch;
                #endif
            }

            if (FollowTarget != null)
            {
                _initialTargetRotation = FollowTarget.localRotation;
            }
        }

        // 自定义 Update 处理叠加逻辑
        protected override void Update()
        {
            if (_activeShakes.Count == 0)
            {
                Stop();
                return;
            }

            float totalX = 0f;
            float totalY = 0f;
            float totalZ = 0f;

            // 倒序遍历列表
            for (int i = _activeShakes.Count - 1; i >= 0; i--)
            {
                var shake = _activeShakes[i];

                // 更新时间
                float deltaTime = (shake.TimescaleMode == TimescaleModes.Scaled) ? Time.deltaTime : Time.unscaledDeltaTime;
                shake.Timer += deltaTime;

                // 计算当前强度
                float percent = Mathf.Clamp01(shake.Timer / shake.Duration);
                float curveValue = shake.Curve.Evaluate(percent);
                float currentIntensity = curveValue * shake.Intensity;

                // 累加 Euler 角度
                totalX += shake.Amplitude.x * currentIntensity;
                totalY += shake.Amplitude.y * currentIntensity;
                totalZ += shake.Amplitude.z * currentIntensity;

                // 移除过期震动
                if (shake.Timer >= shake.Duration)
                {
                    _activeShakes.RemoveAt(i);
                }
            }

            // 应用总偏移
            ApplyRotation(totalX, totalY, totalZ);

            // 更新 Debug 计数
            ActiveShakesCount = _activeShakes.Count;

            // 如果所有震动结束，强制归位
            if (_activeShakes.Count == 0)
            {
                ApplyRotation(0f, 0f, 0f);
            }
        }

        protected virtual void ApplyRotation(float xOffset, float yOffset, float zOffset)
        {
            // Z -> Dutch (直接加法)
            if (_targetCamera != null)
            {
                #if MM_CINEMACHINE
                _targetCamera.m_Lens.Dutch = _initialDutch + zOffset;
                #elif MM_CINEMACHINE3
                _targetCamera.Lens.Dutch = _initialDutch + zOffset;
                #endif
            }

            // X/Y -> FollowTarget (Quaternion 乘法)
            if (FollowTarget != null)
            {
                // 注意：这里我们将叠加后的 Euler 角度转换为 Quaternion，然后应用到初始旋转上
                FollowTarget.localRotation = _initialTargetRotation * Quaternion.Euler(xOffset, yOffset, 0f);
            }
        }

        public virtual void OnMMCinemachineRotationShakeEvent(MMF_Feedback source,
            AnimationCurve shakeCurve, float duration, Vector3 rotationAmplitude, 
            float remapMin, float remapMax, bool relative, float feedbacksIntensity = 1.0f, 
            MMChannelData channelData = null, bool resetShakerValuesAfterShake = true, 
            bool resetTargetValuesAfterShake = true, bool forwardDirection = true, 
            TimescaleModes timescaleMode = TimescaleModes.Scaled, bool stop = false, bool restore = false)
        {
            if (!CheckEventAllowed(channelData)) return;

            if (stop)
            {
                Stop();
                return;
            }
            if (restore)
            {
                ResetTargetValues();
                return;
            }

            // 创建新实例并加入列表
            MMCinemachineRotationShakeInstance newShake = new MMCinemachineRotationShakeInstance(
                duration,
                rotationAmplitude, // 这里的 Amplitude 已经是外部传入的基准值，Intensity 在 Update 中计算
                shakeCurve,
                feedbacksIntensity,
                timescaleMode
            );

            _activeShakes.Add(newShake);
            Play(source);
        }

        public override void Stop()
        {
            _activeShakes.Clear();
            ApplyRotation(0f, 0f, 0f);
        }

        protected override void ResetTargetValues()
        {
            base.ResetTargetValues();
            Stop();
        }

        public override void StartListening()
        {
            base.StartListening();
            MMCinemachineRotationShakeEvent.Register(OnMMCinemachineRotationShakeEvent);
        }

        public override void StopListening()
        {
            base.StopListening();
            MMCinemachineRotationShakeEvent.Unregister(OnMMCinemachineRotationShakeEvent);
        }
    }
}