using System;
using UnityEngine;
using Lean.Pool;
using Sirenix.OdinInspector;

namespace Cielonos.MainGame
{
    public class LightGradient : MonoBehaviour, IPoolable
    {
        [Required] public Light targetLight;

        [Tooltip("在特效生成时是否立刻启用渐变，注意，必须通过对象池生成。\n为true时，渐变效果从targetLight的默认intensity开始，否则需要调用EnableFade方法启用渐变")]
        public bool playOnSpawn = true;

        [Tooltip("光源渐变的生命周期")] public float life = 1f;
        
        [Tooltip("是否应用强度变化")] public bool applyIntensityFade = true;
        [Tooltip("初始强度")] [ShowIf("applyIntensityFade")] public float initialIntensity = 1;
        [Tooltip("渐变曲线")] [ShowIf("applyIntensityFade")] public AnimationCurve intensityFadeCurve;
        
        [Tooltip("是否应用范围变化")] public bool applyRangeFade = false;
        [Tooltip("初始范围")][ShowIf("applyRangeFade")]  public float initialRange = 1;
        [Tooltip("范围曲线")][ShowIf("applyRangeFade")]  public AnimationCurve rangeFadeCurve;
        
        [Tooltip("是否使用光源颜色渐变")] public bool useLightColorGradient = false;
        [Tooltip("光源颜色渐变")][ShowIf("useLightColorGradient")] public Gradient lightColorGradient;

        [HideInEditorMode]
        [SerializeField]
        private bool isFading;
        [HideInEditorMode]
        [SerializeField]
        private float time;
        
        private void Reset()
        {
            targetLight = GetComponent<Light>();
            intensityFadeCurve = AnimationCurve.EaseInOut(0, 1, 1, 0);
            rangeFadeCurve = AnimationCurve.EaseInOut(0, 1, 1, 0);
        }

        public void OnSpawn()
        {
            if (playOnSpawn && !isFading)
            {
                EnableFade(initialIntensity, initialRange);
            }
        }

        public void OnDespawn()
        {
            isFading = false;
        }

        public void EnableFade(float intensity, float initialRange)
        {
            if (targetLight == null) throw new NullReferenceException("Target Light is null");

            time = 0;
            isFading = true;
            if (applyIntensityFade)
            {
                this.initialIntensity = intensity;
                targetLight.intensity = intensity;
            }

            if (applyRangeFade)
            {
                this.initialRange = initialRange;
                targetLight.range = initialRange;
            }
        }


        void Update()
        {
            if (!isFading) return;
            
            time += Time.deltaTime;
            
            if (applyIntensityFade)
            {
                targetLight.intensity = initialIntensity * intensityFadeCurve.Evaluate(time / life);
            }

            if (applyRangeFade)
            {
                targetLight.range = initialRange * rangeFadeCurve.Evaluate(time / life);
            }
            
            if (useLightColorGradient)
            {
                targetLight.color = lightColorGradient.Evaluate(time / life);
            }
            
            if (time > life)
            {
                time = 0;
                isFading = false;
            }
        }
    }
}