using System;
using System.Collections.Generic;
using Unity.Collections;
using UnityEngine.Scripting.APIUpdating;

namespace UnityEngine.Rendering.Universal
{
    [MovedFrom("UnityEngine.Rendering.LWRP")] public enum MixedLightingSetup
    {
        None,
        ShadowMask,
        Subtractive,
    };

    [MovedFrom("UnityEngine.Rendering.LWRP")] public struct RenderingData
    {
        public CullingResults cullResults;
        public CameraData cameraData;
        public LightData lightData;
        public ShadowData shadowData;
        public PostProcessingData postProcessingData;
        public bool supportsDynamicBatching;
        public PerObjectData perObjectData;
        public bool killAlphaInFinalBlit;
    }

    [MovedFrom("UnityEngine.Rendering.LWRP")] public struct LightData
    {
        public int mainLightIndex;
        public int additionalLightsCount;
        public int maxPerObjectAdditionalLightsCount;
        public NativeArray<VisibleLight> visibleLights;
        public bool shadeAdditionalLightsPerVertex;
        public bool supportsMixedLighting;
    }

    [MovedFrom("UnityEngine.Rendering.LWRP")] public struct CameraData
    {
        public Camera camera;
        public RenderTextureDescriptor cameraTargetDescriptor;
        public float renderScale;
        public bool isSceneViewCamera;
        public bool isDefaultViewport;
        public bool isHdrEnabled;
        public bool requiresDepthTexture;
        public bool requiresOpaqueTexture;

        public SortingCriteria defaultOpaqueSortFlags;

        public bool isStereoEnabled;

        public float maxShadowDistance;
        public bool postProcessEnabled;

#if POST_PROCESSING_STACK_2_0_0_OR_NEWER
        [Obsolete("The use of the Post-processing Stack V2 is deprecated in the Universal Render Pipeline. Use the builtin post-processing effects instead.")]
        public UnityEngine.Rendering.PostProcessing.PostProcessLayer postProcessLayer;
#endif

        public IEnumerator<Action<RenderTargetIdentifier, CommandBuffer>> captureActions;

        public LayerMask volumeLayerMask;
        public Transform volumeTrigger;

        public bool isStopNaNEnabled;
        public bool isDitheringEnabled;
        public AntialiasingMode antialiasing;
        public AntialiasingQuality antialiasingQuality;
    }

    [MovedFrom("UnityEngine.Rendering.LWRP")] public struct ShadowData
    {
        public bool supportsMainLightShadows;
        public bool requiresScreenSpaceShadowResolve;
        public int mainLightShadowmapWidth;
        public int mainLightShadowmapHeight;
        public int mainLightShadowCascadesCount;
        public Vector3 mainLightShadowCascadesSplit;
        public bool supportsAdditionalLightShadows;
        public int additionalLightsShadowmapWidth;
        public int additionalLightsShadowmapHeight;
        public bool supportsSoftShadows;
        public int shadowmapDepthBufferBits;
        public List<Vector4> bias;
    }

    public struct PostProcessingData
    {
        public ColorGradingMode gradingMode;
        public int lutSize;
    }

    public static class ShaderKeywordStrings
    {
        public static readonly string MainLightShadows = "_MAIN_LIGHT_SHADOWS";
        public static readonly string MainLightShadowCascades = "_MAIN_LIGHT_SHADOWS_CASCADE";
        public static readonly string AdditionalLightsVertex = "_ADDITIONAL_LIGHTS_VERTEX";
        public static readonly string AdditionalLightsPixel = "_ADDITIONAL_LIGHTS";
        public static readonly string AdditionalLightShadows = "_ADDITIONAL_LIGHT_SHADOWS";
        public static readonly string SoftShadows = "_SHADOWS_SOFT";
        public static readonly string MixedLightingSubtractive = "_MIXED_LIGHTING_SUBTRACTIVE";

        public static readonly string DepthNoMsaa = "_DEPTH_NO_MSAA";
        public static readonly string DepthMsaa2 = "_DEPTH_MSAA_2";
        public static readonly string DepthMsaa4 = "_DEPTH_MSAA_4";

        public static readonly string LinearToSRGBConversion = "_LINEAR_TO_SRGB_CONVERSION";
        public static readonly string KillAlpha = "_KILL_ALPHA";

        public static readonly string SmaaLow = "_SMAA_PRESET_LOW";
        public static readonly string SmaaMedium = "_SMAA_PRESET_MEDIUM";
        public static readonly string SmaaHigh = "_SMAA_PRESET_HIGH";
        public static readonly string PaniniGeneric = "_GENERIC";
        public static readonly string PaniniUnitDistance = "_UNIT_DISTANCE";
        public static readonly string BloomLQ = "_BLOOM_LQ";
        public static readonly string BloomHQ = "_BLOOM_HQ";
        public static readonly string BloomLQDirt = "_BLOOM_LQ_DIRT";
        public static readonly string BloomHQDirt = "_BLOOM_HQ_DIRT";
        public static readonly string UseRGBM = "_USE_RGBM";
        public static readonly string Distortion = "_DISTORTION";
        public static readonly string ChromaticAberration = "_CHROMATIC_ABERRATION";
        public static readonly string HDRGrading = "_HDR_GRADING";
        public static readonly string TonemapACES = "_TONEMAP_ACES";
        public static readonly string TonemapNeutral = "_TONEMAP_NEUTRAL";
        public static readonly string FilmGrain = "_FILM_GRAIN";
        public static readonly string Fxaa = "_FXAA";
        public static readonly string Dithering = "_DITHERING";

        public static readonly string HighQualitySampling = "_HIGH_QUALITY_SAMPLING";
    }

    public sealed partial class UniversalRenderPipeline
    {
        static List<Vector4> m_ShadowBiasData = new List<Vector4>();

        public static bool IsStereoEnabled(Camera camera)
        {
            if (camera == null)
                throw new ArgumentNullException("camera");

            bool isGameCamera = camera.cameraType == CameraType.Game || camera.cameraType == CameraType.VR;
            return XRGraphics.enabled && isGameCamera && (camera.stereoTargetEye == StereoTargetEyeMask.Both);
        }

        void SortCameras(Camera[] cameras)
        {
            Array.Sort(cameras, (lhs, rhs) => (int)(lhs.depth - rhs.depth));
        }

        static RenderTextureDescriptor CreateRenderTextureDescriptor(Camera camera, float renderScale,
            bool isStereoEnabled, bool isHdrEnabled, int msaaSamples, bool needsAlpha)
        {
            RenderTextureDescriptor desc;
            RenderTextureFormat renderTextureFormatDefault = RenderTextureFormat.Default;

            if (isStereoEnabled)
            {
                desc = XRGraphics.eyeTextureDesc;
                renderTextureFormatDefault = desc.colorFormat;
            }
            else
            {
                desc = new RenderTextureDescriptor(camera.pixelWidth, camera.pixelHeight);
                desc.width = (int)((float)desc.width * renderScale);
                desc.height = (int)((float)desc.height * renderScale);
            }

            bool use32BitHDR = !needsAlpha && RenderingUtils.SupportsRenderTextureFormat(RenderTextureFormat.RGB111110Float);
            RenderTextureFormat hdrFormat = (use32BitHDR) ? RenderTextureFormat.RGB111110Float : RenderTextureFormat.DefaultHDR;
            if (camera.targetTexture != null)
            {
                desc.colorFormat = camera.targetTexture.descriptor.colorFormat;
                desc.depthBufferBits = camera.targetTexture.descriptor.depthBufferBits;
                desc.msaaSamples = camera.targetTexture.descriptor.msaaSamples;
                desc.sRGB = camera.targetTexture.descriptor.sRGB;
            }
            else
            {
                desc.colorFormat = isHdrEnabled ? hdrFormat : renderTextureFormatDefault;
                desc.depthBufferBits = 32;
                desc.msaaSamples = msaaSamples;
                desc.sRGB = (QualitySettings.activeColorSpace == ColorSpace.Linear);
            }
            
            desc.enableRandomWrite = false;
            desc.bindMS = false;
            desc.useDynamicScale = camera.allowDynamicResolution;
            return desc;
        }
    }
}