//pipelinedefine
#define H_URP
using System.Collections.Generic;
using System.Linq;
using HTraceWSGI.Scripts.Extensions;
using HTraceWSGI.Scripts.Globals;
using UnityEngine;
using UnityEngine.Experimental.Rendering;
using UnityEngine.Rendering;

namespace HTraceWSGI.Scripts.Services.LightsCluster
{
	internal sealed class LightService : IService
	{
		internal struct LightInfo
		{
			public Vector3 Position;
		}

		private static readonly int _MaxCookieResolution      = Shader.PropertyToID("_MaxCookieResolution");
		private static readonly int _LightPointCookies_Output = Shader.PropertyToID("_LightPointCookies_Output");
		private static readonly int _LightSpotCookies_Output  = Shader.PropertyToID("_LightSpotCookies_Output");
		
		private static          LightService _instance;

		public static LightService Instance
		{
			get
			{
				if (_instance == null)
					_instance = new LightService();
				return _instance;
			}
		}

		private readonly Dictionary<Light, LightInfo> _lights         = new Dictionary<Light, LightInfo>(10);
		private readonly List<Light>                  _lightsToRemove = new List<Light>(20);
		private readonly List<Light>                  _lightsToUpdate = new List<Light>(20);

		public void Initialize()
		{
			
			HPunctualLight[] findObjectsByType = Object.FindObjectsByType<HPunctualLight>(FindObjectsSortMode.None);
			foreach (var light in findObjectsByType)
			{
				if (light.enabled == true)
					AddLight(light.Light);
			}
		}

		public void AddLight(Light light)
		{
			if (light == null || !light.enabled)
				return;

			if (light.type != LightType.Point && light.type != LightType.Spot)
				return;

			if (_lights.ContainsKey(light))
				return;

			
			var lightInfo = new LightInfo
			{
				Position = light.transform.position,
			};

			_lights[light] = lightInfo;
		}

		public void RemoveLight(Light light)
		{
			if (object.ReferenceEquals(light, null))
				return;

			RemoveLightData(light);
		}

		private void RemoveLightData(Light light)
		{
			if (_lights.TryGetValue(light, out var info))
			{
				_lights.Remove(light);
			}
		}

		public void LateUpdate()
		{
			_lightsToRemove.Clear();
			
			foreach (var kvp in _lights)
			{
				var key = kvp.Key;
				
				if (!key || !key.enabled || (key.type != LightType.Point && key.type != LightType.Spot))
				{
					_lightsToRemove.Add(key);
				}
			}
			
			for (int i = 0; i < _lightsToRemove.Count; i++)
			{
				RemoveLightData(_lightsToRemove[i]);
			}

			_lightsToUpdate.Clear();
			foreach (var kvp in _lights)
			{
				_lightsToUpdate.Add(kvp.Key);
			}

			for (int i = 0; i < _lightsToUpdate.Count; i++)
			{
				var key = _lightsToUpdate[i];
				var lightInfo = _lights[key];

				lightInfo.Position = key.transform.position;
				_lights[key] = lightInfo;
			}
			
			//CleanupUnusedCookies();

		}

		public IEnumerable<LightInfo> GetLights(Camera camera)
		{
			if (camera == null)
				yield break;

			var cameraPosition = camera.transform.position;

			foreach (var kvp in _lights)
			{
				var light = kvp.Key;
				var lightInfo = kvp.Value;

				if (!light || !light.enabled)
					continue;
				{
					yield return lightInfo;
				}
			}
		}

#if NONE
		public IEnumerable<LightInfo> GetLights(Camera camera)
		{
			foreach (var kvp in _lights)
			{
				var light = kvp.Key;
				var lightInfo = kvp.Value;

				if (!light || !light.enabled)
					continue;

				yield return lightInfo;
			}
		}
#endif


		public void Cleanup()
		{
			_lights.Clear();
		}
	}
}