using System.Collections.Generic;
using SLSUtilities.Feedback;
using SLSUtilities.Rendering.PostProcessing;
using UnityEngine;

namespace Cielonos.MainGame.Effects.Feedback
{
    /// <summary>
    /// RGB分离故障震动事件。
    /// </summary>
    public struct RGBSplitGlitchShakeEvent
    {
        private static event ShakeDelegate OnEvent;

        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
        private static void RuntimeInitialization() { OnEvent = null; }

        public delegate void ShakeDelegate(
            FeedbackContext feedbackContext,
            FloatCurveChannel intensityCurve,
            FloatCurveChannel speedCurve,
            bool stop
        );

        public static void Register(ShakeDelegate callback) { OnEvent += callback; }
        public static void Unregister(ShakeDelegate callback) { OnEvent -= callback; }

        public static void Trigger(
            FeedbackContext feedbackContext,
            FloatCurveChannel intensityCurve,
            FloatCurveChannel speedCurve = default,
            bool stop = false)
        {
            OnEvent?.Invoke(feedbackContext, intensityCurve, speedCurve, stop);
        }
    }

    /// <summary>
    /// RGB分离故障震动实例。
    /// </summary>
    public class RGBSplitGlitchShakeInstance : ShakeInstanceBase
    {
        public readonly FloatCurveChannel intensityCurve;
        public readonly FloatCurveChannel speedCurve;

        public RGBSplitGlitchShakeInstance(
            FeedbackContext feedbackContext,
            FloatCurveChannel intensityCurve,
            FloatCurveChannel speedCurve)
            : base(feedbackContext.timeSettings, feedbackContext.player.TimeProvider, feedbackContext.duration)
        {
            this.intensityCurve = intensityCurve;
            this.speedCurve = speedCurve;
        }
    }

    /// <summary>
    /// RGBSplitGlitch 的震动聚合器。
    /// </summary>
    [AddComponentMenu("SLS Utilities/Feedback Shakers/RGB Split Glitch Shaker")]
    public class RGBSplitGlitchShaker : MonoBehaviour
    {
        private RGBSplitGlitch _component;
        private float _initialIntensity;
        private float _initialSpeed;
        private bool _resolved;

        private readonly List<RGBSplitGlitchShakeInstance> _activeShakes = new List<RGBSplitGlitchShakeInstance>();

        private void Awake()
        {
            _resolved = TryResolve();
        }

        private void OnEnable()
        {
            RGBSplitGlitchShakeEvent.Register(OnShakeEvent);
        }

        private void OnDisable()
        {
            RGBSplitGlitchShakeEvent.Unregister(OnShakeEvent);
            StopAll();
        }

        private void Update()
        {
            if (!_resolved || _activeShakes.Count == 0) return;

            float additiveIntensity = 0f;
            float absoluteIntensity = 0f;
            bool hasAbsoluteIntensity = false;
            float additiveSpeed = 0f;
            float absoluteSpeed = 0f;
            bool hasAbsoluteSpeed = false;

            for (int i = _activeShakes.Count - 1; i >= 0; i--)
            {
                RGBSplitGlitchShakeInstance shake = _activeShakes[i];
                shake.timer += shake.timeProvider.GetDeltaTime(shake.timeSettings);

                float normalizedTime = shake.timer / shake.duration;

                float intensityValue = shake.intensityCurve.Evaluate(normalizedTime);
                if (shake.intensityCurve.relativeToInitial)
                {
                    additiveIntensity += intensityValue;
                }
                else
                {
                    absoluteIntensity = intensityValue;
                    hasAbsoluteIntensity = true;
                }

                float speedValue = shake.speedCurve.Evaluate(normalizedTime);
                if (shake.speedCurve.relativeToInitial)
                {
                    additiveSpeed += speedValue;
                }
                else
                {
                    absoluteSpeed = speedValue;
                    hasAbsoluteSpeed = true;
                }

                if (shake.IsFinished)
                {
                    _activeShakes.RemoveAt(i);
                }
            }

            float finalIntensity = hasAbsoluteIntensity ? absoluteIntensity : _initialIntensity + additiveIntensity;
            float finalSpeed = hasAbsoluteSpeed ? absoluteSpeed : _initialSpeed + additiveSpeed;
            _component.intensity.value = finalIntensity;
            _component.speed.value = finalSpeed;

            if (_activeShakes.Count == 0)
            {
                Restore();
            }
        }

        private void OnShakeEvent(
            FeedbackContext feedbackContext,
            FloatCurveChannel intensityCurve,
            FloatCurveChannel speedCurve,
            bool stop)
        {
            if (stop) { StopAll(); return; }
            if (!_resolved) _resolved = TryResolve();
            if (!_resolved) return;

            var instance = new RGBSplitGlitchShakeInstance(
                feedbackContext,
                intensityCurve,
                speedCurve
            );
            _activeShakes.Add(instance);
        }

        private bool TryResolve()
        {
            if (_component != null) return true;
            if (PostProcessingManager.Instance == null) return false;
            if (!PostProcessingManager.Instance.GetVolumeComponent(out _component)) return false;

            _initialIntensity = _component.intensity.value;
            _initialSpeed = _component.speed.value;
            return true;
        }

        private void Restore()
        {
            if (!_resolved) return;
            _component.intensity.value = _initialIntensity;
            _component.speed.value = _initialSpeed;
        }

        private void StopAll()
        {
            _activeShakes.Clear();
            Restore();
        }
    }
}