using System;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Rendering;
using UnityEngine.Playables;
using UnityEngine.Timeline;

namespace AibisDream.FixSystem
{
    [RequireComponent(typeof(Slider))]
    public class MemorySlider : MonoBehaviour
    {
        [SerializeField] private float defaultValue = 0f;
        [SerializeField] private float sliderMaxValue = 6f;
        [SerializeField] private float lockThreshold = 0.06f;
        [SerializeField] private TimelineAsset openAsset;
        [SerializeField] private TimelineAsset closeAsset;

        private Slider slider;
        private PlayableDirector playableDirector;
        private Volume _volume;

        /// <summary>视觉 Lock/Unlock（Timeline）；true = 收起未开，false = 已打开。</summary>
        private bool isLocked;

        public float TargetValue { get; set; }
        public bool IsFound { get; private set; }

        public event Action OnFound;
        public event Action OnLost;

        public void Init(Volume volume)
        {
            slider = GetComponent<Slider>();
            playableDirector = GetComponent<PlayableDirector>();

            _volume = volume;
            IsFound = false;
            slider.onValueChanged.RemoveAllListeners();
            slider.onValueChanged.AddListener(HandleValueChanged);
            slider.maxValue = sliderMaxValue;
            slider.value = defaultValue;
            UpdateVolumeWeight(slider.value);

            isLocked = true;
            SetInteractable(false);
        }

        /// <summary>仅控制是否可拖动，与 <see cref="UnlockSlider"/> / <see cref="LockSlider"/> 无关。</summary>
        public void SetInteractable(bool interactable) => slider.interactable = interactable;

        /// <summary>
        /// 新一轮搜索前复位滑条与 IsFound（不播 Timeline、不改变视觉锁状态）。
        /// 需先设置好 <see cref="TargetValue"/>。
        /// </summary>
        public void PrepareForSearch()
        {
            slider.value = defaultValue;
            HandleValueChanged(slider.value);
        }

        /// <summary>仅播放打开 Timeline（若有），不碰 interactable。</summary>
        public void UnlockSlider(Action onComplete = null)
        {
            if (!isLocked)
            {
                onComplete?.Invoke();
                return;
            }

            PlayTimeline(openAsset, () =>
            {
                isLocked = false;
                onComplete?.Invoke();
            });
        }

        /// <summary>仅播放收起 Timeline（若有），不碰 interactable。</summary>
        public void LockSlider(Action onComplete = null)
        {
            if (isLocked)
            {
                onComplete?.Invoke();
                return;
            }

            slider.value = 0f;
            UpdateVolumeWeight(0f);

            PlayTimeline(closeAsset, () =>
            {
                isLocked = true;
                onComplete?.Invoke();
            });
        }

        private void HandleValueChanged(float value)
        {
            float t = UpdateVolumeWeight(value);

            bool wasFound = IsFound;
            IsFound = t < lockThreshold;

            if (IsFound && !wasFound)
                OnFound?.Invoke();
            else if (!IsFound && wasFound)
                OnLost?.Invoke();
        }

        private float UpdateVolumeWeight(float value)
        {
            float distance = Mathf.Abs(value - TargetValue);
            float maxDistance = Mathf.Max(
                Mathf.Abs(slider.maxValue - TargetValue),
                Mathf.Abs(slider.minValue - TargetValue)
            );
            float t = Mathf.Clamp01(distance / maxDistance);

            if (_volume != null)
                _volume.weight = Mathf.Lerp(0, 1, t);

            return t;
        }

        private void PlayTimeline(TimelineAsset asset, Action onComplete)
        {
            if (asset == null || playableDirector == null)
            {
                onComplete?.Invoke();
                return;
            }

            playableDirector.Stop();
            playableDirector.playableAsset = asset;
            playableDirector.time = 0;
            playableDirector.extrapolationMode = DirectorWrapMode.None;

            Action<PlayableDirector> callback = null;
            callback = pd =>
            {
                playableDirector.stopped -= callback;
                onComplete?.Invoke();
            };
            playableDirector.stopped += callback;
            playableDirector.Play();
        }
    }
}