using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

namespace FlatKit;

public class FlatKitFog : ScriptableRendererFeature
{
	[Tooltip("To create new settings use 'Create > FlatKit > Fog Settings'.")]
	public FogSettings settings;

	[SerializeField]
	[HideInInspector]
	private Material _effectMaterial;

	private BlitTexturePass _blitTexturePass;

	private RenderTargetHandle _fogTexture;

	private Texture2D _lutDepth;

	private Texture2D _lutHeight;

	private static readonly string FogShaderName = "Hidden/FlatKit/FogFilter";

	private static readonly int DistanceLut = Shader.PropertyToID("_DistanceLUT");

	private static readonly int Near = Shader.PropertyToID("_Near");

	private static readonly int Far = Shader.PropertyToID("_Far");

	private static readonly int UseDistanceFog = Shader.PropertyToID("_UseDistanceFog");

	private static readonly int UseDistanceFogOnSky = Shader.PropertyToID("_UseDistanceFogOnSky");

	private static readonly int DistanceFogIntensity = Shader.PropertyToID("_DistanceFogIntensity");

	private static readonly int HeightLut = Shader.PropertyToID("_HeightLUT");

	private static readonly int LowWorldY = Shader.PropertyToID("_LowWorldY");

	private static readonly int HighWorldY = Shader.PropertyToID("_HighWorldY");

	private static readonly int UseHeightFog = Shader.PropertyToID("_UseHeightFog");

	private static readonly int UseHeightFogOnSky = Shader.PropertyToID("_UseHeightFogOnSky");

	private static readonly int HeightFogIntensity = Shader.PropertyToID("_HeightFogIntensity");

	private static readonly int DistanceHeightBlend = Shader.PropertyToID("_DistanceHeightBlend");

	public override void Create()
	{
		if (settings == null)
		{
			Debug.LogWarning("[FlatKit] Missing Fog Settings");
			return;
		}
		_blitTexturePass = new BlitTexturePass
		{
			renderPassEvent = settings.renderEvent
		};
		_fogTexture.Init("_EffectTexture");
	}

	public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
	{
		if (settings == null)
		{
			Debug.LogWarning("[FlatKit] Missing Fog Settings");
		}
		else if (CreateMaterials())
		{
			SetMaterialProperties();
			_blitTexturePass.Setup(_effectMaterial, useDepth: true, useNormals: false, useColor: false);
			renderer.EnqueuePass(_blitTexturePass);
		}
	}

	protected override void Dispose(bool disposing)
	{
		CoreUtils.Destroy(_effectMaterial);
	}

	private bool CreateMaterials()
	{
		if (_effectMaterial == null)
		{
			Shader shader = Shader.Find(FogShaderName);
			Shader shader2 = Shader.Find(BlitTexturePass.CopyEffectShaderName);
			if (shader == null || shader2 == null)
			{
				return false;
			}
			_effectMaterial = CoreUtils.CreateEngineMaterial(shader);
		}
		return true;
	}

	private void SetMaterialProperties()
	{
		if (!(_effectMaterial == null))
		{
			UpdateDistanceLut();
			_effectMaterial.SetTexture(DistanceLut, _lutDepth);
			_effectMaterial.SetFloat(Near, settings.near);
			_effectMaterial.SetFloat(Far, settings.far);
			_effectMaterial.SetFloat(UseDistanceFog, settings.useDistance ? 1f : 0f);
			_effectMaterial.SetFloat(UseDistanceFogOnSky, settings.useDistanceFogOnSky ? 1f : 0f);
			_effectMaterial.SetFloat(DistanceFogIntensity, settings.distanceFogIntensity);
			UpdateHeightLut();
			_effectMaterial.SetTexture(HeightLut, _lutHeight);
			_effectMaterial.SetFloat(LowWorldY, settings.low);
			_effectMaterial.SetFloat(HighWorldY, settings.high);
			_effectMaterial.SetFloat(UseHeightFog, settings.useHeight ? 1f : 0f);
			_effectMaterial.SetFloat(UseHeightFogOnSky, settings.useHeightFogOnSky ? 1f : 0f);
			_effectMaterial.SetFloat(HeightFogIntensity, settings.heightFogIntensity);
			_effectMaterial.SetFloat(DistanceHeightBlend, settings.distanceHeightBlend);
		}
	}

	private void UpdateDistanceLut()
	{
		if (settings.distanceGradient == null)
		{
			return;
		}
		if (_lutDepth != null)
		{
			Object.DestroyImmediate(_lutDepth);
		}
		_lutDepth = new Texture2D(256, 1, TextureFormat.RGBA32, mipChain: false)
		{
			wrapMode = TextureWrapMode.Clamp,
			hideFlags = HideFlags.HideAndDontSave,
			filterMode = FilterMode.Bilinear
		};
		for (float num = 0f; num < 256f; num += 1f)
		{
			Color color = settings.distanceGradient.Evaluate(num / 255f);
			for (float num2 = 0f; num2 < 1f; num2 += 1f)
			{
				_lutDepth.SetPixel(Mathf.CeilToInt(num), Mathf.CeilToInt(num2), color);
			}
		}
		_lutDepth.Apply();
	}

	private void UpdateHeightLut()
	{
		if (settings.heightGradient == null)
		{
			return;
		}
		if (_lutHeight != null)
		{
			Object.DestroyImmediate(_lutHeight);
		}
		_lutHeight = new Texture2D(256, 1, TextureFormat.RGBA32, mipChain: false)
		{
			wrapMode = TextureWrapMode.Clamp,
			hideFlags = HideFlags.HideAndDontSave,
			filterMode = FilterMode.Bilinear
		};
		for (float num = 0f; num < 256f; num += 1f)
		{
			Color color = settings.heightGradient.Evaluate(num / 255f);
			for (float num2 = 0f; num2 < 1f; num2 += 1f)
			{
				_lutHeight.SetPixel(Mathf.CeilToInt(num), Mathf.CeilToInt(num2), color);
			}
		}
		_lutHeight.Apply();
	}
}