using System;
using XCEngine;

namespace XCEngine.Rendering
{
    public sealed class ScriptableRenderContext
    {
        private enum RecordedScenePhase
        {
            Opaque = 0,
            Skybox = 1,
            Transparent = 3
        }

        private enum RecordedSceneInjectionPoint
        {
            BeforeOpaque = 0,
            AfterOpaque = 1,
            BeforeSkybox = 2,
            AfterSkybox = 3,
            BeforeTransparent = 4,
            AfterTransparent = 5
        }

        private enum RecordedFullscreenPassType
        {
            ColorScale = 0,
            ShaderVector = 1
        }

        private readonly ulong m_nativeHandle;
        private CameraData m_cameraData;
        private LightingData m_lightingData;
        private ShadowData m_shadowData;
        private EnvironmentData m_environmentData;
        private FinalColorData m_finalColorData;
        private StageColorData m_stageColorData;

        internal ScriptableRenderContext(ulong nativeHandle)
        {
            m_nativeHandle = nativeHandle;
        }

        public CameraFrameStage stage =>
            (CameraFrameStage)InternalCalls.Rendering_ScriptableRenderContext_GetStage(
                m_nativeHandle);

        public CameraData cameraData =>
            m_cameraData ?? (m_cameraData = ResolveCameraData());

        public LightingData lightingData =>
            m_lightingData ?? (m_lightingData = ResolveLightingData());

        public ShadowData shadowData =>
            m_shadowData ?? (m_shadowData = ResolveShadowData());

        public EnvironmentData environmentData =>
            m_environmentData ??
            (m_environmentData = ResolveEnvironmentData());

        public FinalColorData finalColorData =>
            m_finalColorData ??
            (m_finalColorData = ResolveFinalColorData());

        public StageColorData stageColorData =>
            m_stageColorData ??
            (m_stageColorData = ResolveStageColorData());

        public bool RecordScene()
        {
            return InternalCalls
                .Rendering_ScriptableRenderContext_RecordScene(
                    m_nativeHandle);
        }

        public bool RecordOpaqueScenePhase()
        {
            return RecordScenePhaseInternal(
                RecordedScenePhase.Opaque);
        }

        public bool RecordSkyboxScenePhase()
        {
            return RecordScenePhaseInternal(
                RecordedScenePhase.Skybox);
        }

        public bool RecordTransparentScenePhase()
        {
            return RecordScenePhaseInternal(
                RecordedScenePhase.Transparent);
        }

        public bool RecordBeforeOpaqueInjection()
        {
            return RecordSceneInjectionPointInternal(
                RecordedSceneInjectionPoint.BeforeOpaque);
        }

        public bool RecordAfterOpaqueInjection()
        {
            return RecordSceneInjectionPointInternal(
                RecordedSceneInjectionPoint.AfterOpaque);
        }

        public bool RecordBeforeSkyboxInjection()
        {
            return RecordSceneInjectionPointInternal(
                RecordedSceneInjectionPoint.BeforeSkybox);
        }

        public bool RecordAfterSkyboxInjection()
        {
            return RecordSceneInjectionPointInternal(
                RecordedSceneInjectionPoint.AfterSkybox);
        }

        public bool RecordBeforeTransparentInjection()
        {
            return RecordSceneInjectionPointInternal(
                RecordedSceneInjectionPoint.BeforeTransparent);
        }

        public bool RecordAfterTransparentInjection()
        {
            return RecordSceneInjectionPointInternal(
                RecordedSceneInjectionPoint.AfterTransparent);
        }

        public bool RecordColorScaleFullscreenPass(
            Vector4 colorScale)
        {
            return RecordFullscreenPassInternal(
                RecordedFullscreenPassType.ColorScale,
                string.Empty,
                string.Empty,
                colorScale);
        }

        public bool RecordShaderVectorFullscreenPass(
            string shaderPath,
            Vector4 vectorPayload,
            string passName = null)
        {
            if (string.IsNullOrEmpty(shaderPath))
            {
                throw new ArgumentException(
                    "Fullscreen shader path cannot be null or empty.",
                    nameof(shaderPath));
            }

            return RecordFullscreenPassInternal(
                RecordedFullscreenPassType.ShaderVector,
                shaderPath,
                passName ?? string.Empty,
                vectorPayload);
        }

        private bool RecordScenePhaseInternal(
            RecordedScenePhase scenePhase)
        {
            return InternalCalls
                .Rendering_ScriptableRenderContext_RecordScenePhase(
                    m_nativeHandle,
                    (int)scenePhase);
        }

        private bool RecordSceneInjectionPointInternal(
            RecordedSceneInjectionPoint injectionPoint)
        {
            return InternalCalls
                .Rendering_ScriptableRenderContext_RecordSceneInjectionPoint(
                    m_nativeHandle,
                    (int)injectionPoint);
        }

        private bool RecordFullscreenPassInternal(
            RecordedFullscreenPassType passType,
            string shaderPath,
            string passName,
            Vector4 vectorPayload)
        {
            return InternalCalls
                .Rendering_ScriptableRenderContext_RecordFullscreenPass(
                    m_nativeHandle,
                    (int)passType,
                    shaderPath,
                    passName,
                    ref vectorPayload);
        }

        private CameraData ResolveCameraData()
        {
            Matrix4x4 view;
            Matrix4x4 projection;
            Matrix4x4 viewProjection;
            Vector3 worldPosition;
            Vector3 worldRight;
            Vector3 worldUp;
            Vector3 worldForward;
            Color clearColor;

            InternalCalls
                .Rendering_ScriptableRenderContext_GetCameraView(
                    m_nativeHandle,
                    out view);
            InternalCalls
                .Rendering_ScriptableRenderContext_GetCameraProjection(
                    m_nativeHandle,
                    out projection);
            InternalCalls
                .Rendering_ScriptableRenderContext_GetCameraViewProjection(
                    m_nativeHandle,
                    out viewProjection);
            InternalCalls
                .Rendering_ScriptableRenderContext_GetCameraWorldPosition(
                    m_nativeHandle,
                    out worldPosition);
            InternalCalls
                .Rendering_ScriptableRenderContext_GetCameraWorldRight(
                    m_nativeHandle,
                    out worldRight);
            InternalCalls
                .Rendering_ScriptableRenderContext_GetCameraWorldUp(
                    m_nativeHandle,
                    out worldUp);
            InternalCalls
                .Rendering_ScriptableRenderContext_GetCameraWorldForward(
                    m_nativeHandle,
                    out worldForward);
            InternalCalls
                .Rendering_ScriptableRenderContext_GetCameraClearColor(
                    m_nativeHandle,
                    out clearColor);

            return new CameraData(
                view,
                projection,
                viewProjection,
                worldPosition,
                worldRight,
                worldUp,
                worldForward,
                clearColor,
                (RenderClearFlags)InternalCalls
                    .Rendering_ScriptableRenderContext_GetCameraClearFlags(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetCameraPerspectiveProjection(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetCameraVerticalFovRadians(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetCameraOrthographicSize(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetCameraAspectRatio(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetCameraNearClipPlane(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetCameraFarClipPlane(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetCameraViewportWidth(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetCameraViewportHeight(
                        m_nativeHandle));
        }

        private LightingData ResolveLightingData()
        {
            Vector3 mainDirectionalLightDirection;
            Color mainDirectionalLightColor;

            InternalCalls
                .Rendering_ScriptableRenderContext_GetMainDirectionalLightDirection(
                    m_nativeHandle,
                    out mainDirectionalLightDirection);
            InternalCalls
                .Rendering_ScriptableRenderContext_GetMainDirectionalLightColor(
                    m_nativeHandle,
                    out mainDirectionalLightColor);

            return new LightingData(
                new DirectionalLightData(
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalLightEnabled(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalLightCastsShadows(
                            m_nativeHandle),
                    mainDirectionalLightDirection,
                    mainDirectionalLightColor,
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalLightIntensity(
                            m_nativeHandle)),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetHasMainDirectionalShadow(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetAdditionalLightCount(
                        m_nativeHandle));
        }

        private EnvironmentData ResolveEnvironmentData()
        {
            Color skyboxTopColor;
            Color skyboxHorizonColor;
            Color skyboxBottomColor;

            InternalCalls
                .Rendering_ScriptableRenderContext_GetEnvironmentSkyboxTopColor(
                    m_nativeHandle,
                    out skyboxTopColor);
            InternalCalls
                .Rendering_ScriptableRenderContext_GetEnvironmentSkyboxHorizonColor(
                    m_nativeHandle,
                    out skyboxHorizonColor);
            InternalCalls
                .Rendering_ScriptableRenderContext_GetEnvironmentSkyboxBottomColor(
                    m_nativeHandle,
                    out skyboxBottomColor);

            return new EnvironmentData(
                (RenderEnvironmentMode)InternalCalls
                    .Rendering_ScriptableRenderContext_GetEnvironmentMode(
                        m_nativeHandle),
                skyboxTopColor,
                skyboxHorizonColor,
                skyboxBottomColor);
        }

        private ShadowData ResolveShadowData()
        {
            Matrix4x4 viewProjection;

            InternalCalls
                .Rendering_ScriptableRenderContext_GetMainDirectionalShadowViewProjection(
                    m_nativeHandle,
                    out viewProjection);

            return new ShadowData(
                new DirectionalShadowData(
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowEnabled(
                            m_nativeHandle),
                    viewProjection,
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowOrthographicHalfExtent(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowNearClipPlane(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowFarClipPlane(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowMapWidth(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowMapHeight(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowWorldTexelSize(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowReceiverDepthBias(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowNormalBiasScale(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowStrength(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowDepthBiasFactor(
                            m_nativeHandle),
                    InternalCalls
                        .Rendering_ScriptableRenderContext_GetMainDirectionalShadowDepthBiasUnits(
                            m_nativeHandle)));
        }

        private FinalColorData ResolveFinalColorData()
        {
            Vector4 finalColorScale;

            InternalCalls
                .Rendering_ScriptableRenderContext_GetFinalColorScale(
                    m_nativeHandle,
                    out finalColorScale);

            FinalColorSettings settings =
                FinalColorSettings.CreateDefault();
            settings.outputTransferMode =
                (FinalColorOutputTransferMode)InternalCalls
                    .Rendering_ScriptableRenderContext_GetFinalColorOutputTransferMode(
                        m_nativeHandle);
            settings.exposureMode =
                (FinalColorExposureMode)InternalCalls
                    .Rendering_ScriptableRenderContext_GetFinalColorExposureMode(
                        m_nativeHandle);
            settings.exposureValue =
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetFinalColorExposureValue(
                        m_nativeHandle);
            settings.toneMappingMode =
                (FinalColorToneMappingMode)InternalCalls
                    .Rendering_ScriptableRenderContext_GetFinalColorToneMappingMode(
                        m_nativeHandle);
            settings.finalColorScale =
                finalColorScale;

            return new FinalColorData(
                settings,
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetFinalColorHasPipelineDefaults(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetFinalColorHasCameraOverrides(
                        m_nativeHandle));
        }

        private StageColorData ResolveStageColorData()
        {
            return new StageColorData(
                (CameraFrameColorSource)InternalCalls
                    .Rendering_ScriptableRenderContext_GetStageColorSource(
                        m_nativeHandle),
                InternalCalls
                    .Rendering_ScriptableRenderContext_GetStageUsesGraphManagedOutputColor(
                        m_nativeHandle));
        }
    }
}