using System;
using System.Linq;

#if UNITY_EDITOR
using UnityEditor.Rendering;
using UnityEngine.Assertions;
#endif

namespace UnityEngine.Rendering.HighDefinition
{
    partial class HDRenderPipelineGlobalSettings : IVersionable<HDRenderPipelineGlobalSettings.Version>, IMigratableAsset
    {
        // Keep in mind that if there is no HDRenderPipelineGlobalSettings,
        // it can be created from one HDRPAsset in GraphicSettings before version AddedHDRenderPipelineGlobalSettings.
        // When it occurs we force Version to be First again for all migration step to occures again.
        //
        // /!\ If you add data that are not from HDRPAsset and then add a migration pattern on them,
        // don't forget to add your migration step into skipedStepWhenCreatedFromHDRPAsset.
        //
        // /!\ Also for each new version, you must now upgrade asset in HDRP_Runtime, HDRP_Performance and SRP_SmokeTest test project.
        internal enum Version
        {
            First,
            UpdateMSAA,
            UpdateLensFlare,
            MovedSupportRuntimeDebugDisplayToGlobalSettings,
            DisableAutoRegistration,
            MoveDiffusionProfilesToVolume,
            GenericRenderingLayers,
            SupportRuntimeDebugDisplayToStripRuntimeDebugShaders,
            EnableAmethystFeaturesByDefault,
            ShaderStrippingSettings,
            RenderingPathFrameSettings,
            CustomPostProcessOrdersSettings,
            SetUpIncluderRenderPipelineAssetGraphicsSettings,
            ToRenderPipelineGraphicsSettings,
            RenderingLayerMask,
        }

        static Version[] skipedStepWhenCreatedFromHDRPAsset = new Version[] { };

        [SerializeField]
        internal Version m_Version = MigrationDescription.LastVersion<Version>();
        Version IVersionable<Version>.version { get => m_Version; set => m_Version = value; }

#if UNITY_EDITOR
        static readonly MigrationDescription<Version, HDRenderPipelineGlobalSettings> k_Migration = MigrationDescription.New(
            MigrationStep.New(Version.UpdateMSAA, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                FrameSettingsOverrideMask unusedMaskForDefault = new FrameSettingsOverrideMask();
                FrameSettings.MigrateMSAA(ref data.m_ObsoleteRenderingPathDefaultCameraFrameSettings, ref unusedMaskForDefault);
                FrameSettings.MigrateMSAA(ref data.m_ObsoleteRenderingPathDefaultBakedOrCustomReflectionFrameSettings, ref unusedMaskForDefault);
                FrameSettings.MigrateMSAA(ref data.m_ObsoleteRenderingPathDefaultRealtimeReflectionFrameSettings, ref unusedMaskForDefault);
#pragma warning restore 618
            }),

            MigrationStep.New(Version.UpdateLensFlare, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                FrameSettings.MigrateToLensFlare(ref data.m_ObsoleteRenderingPathDefaultCameraFrameSettings);
#pragma warning restore 618
            }),
            MigrationStep.New(Version.MovedSupportRuntimeDebugDisplayToGlobalSettings, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                if (GraphicsSettings.currentRenderPipeline is HDRenderPipelineAsset activePipeline)
                {
                    data.m_SupportRuntimeDebugDisplay = activePipeline.currentPlatformRenderPipelineSettings.m_ObsoleteSupportRuntimeDebugDisplay;
                }
#pragma warning restore 618
            }),
            MigrationStep.New(Version.DisableAutoRegistration, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                // Field is on for new projects, but disable it for existing projects
                data.autoRegisterDiffusionProfiles = false;
#pragma warning restore 618
            }),
            MigrationStep.New(Version.MoveDiffusionProfilesToVolume, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                if (data.m_ObsoleteDiffusionProfileSettingsList == null ||
                    data.m_ObsoleteDiffusionProfileSettingsList.Length == 0)
                    return;

                // Ensure the default volume exists at this point
                var defaultVolumeProfile = GetOrCreateGraphicsSettings<HDRenderPipelineEditorAssets>(data).defaultVolumeProfile;
                if (data.m_ObsoleteDefaultVolumeProfile != null && VolumeUtils.IsDefaultVolumeProfile(data.m_ObsoleteDefaultVolumeProfile, defaultVolumeProfile))
                {
                    // Profile from resources is read only in released packages, so we have to copy it to the assets folder
                    data.m_ObsoleteDefaultVolumeProfile = null;
                }

                if (data.m_ObsoleteDefaultVolumeProfile == null)
                {
                    data.m_ObsoleteDefaultVolumeProfile = VolumeUtils.CopyVolumeProfileFromResourcesToAssets(defaultVolumeProfile);
                }

                UnityEditor.AssetDatabase.MakeEditable(UnityEditor.AssetDatabase.GetAssetPath(data.m_ObsoleteDefaultVolumeProfile));

                VolumeUtils.TryAddDiffusionProfiles(data.m_ObsoleteDefaultVolumeProfile, data.m_ObsoleteDiffusionProfileSettingsList);
#pragma warning restore 618
            }),
            MigrationStep.New(Version.GenericRenderingLayers, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                data.renderingLayerNames = new string[16]
                {
                    data.lightLayerName0,
                    data.lightLayerName1,
                    data.lightLayerName2,
                    data.lightLayerName3,
                    data.lightLayerName4,
                    data.lightLayerName5,
                    data.lightLayerName6,
                    data.lightLayerName7,
                    data.decalLayerName0,
                    data.decalLayerName1,
                    data.decalLayerName2,
                    data.decalLayerName3,
                    data.decalLayerName4,
                    data.decalLayerName5,
                    data.decalLayerName6,
                    data.decalLayerName7,
                };

                data.GetDefaultFrameSettings(FrameSettingsRenderType.Camera).SetEnabled(FrameSettingsField.RenderingLayerMaskBuffer, true);
#pragma warning restore 618
            }),
            MigrationStep.New(Version.SupportRuntimeDebugDisplayToStripRuntimeDebugShaders, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                data.m_StripDebugVariants = !data.m_SupportRuntimeDebugDisplay; // Inversion logic
#pragma warning restore 618
            }),
            MigrationStep.New(Version.EnableAmethystFeaturesByDefault, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                FrameSettings.MigrateAmethystFeatures(ref data.m_ObsoleteRenderingPathDefaultCameraFrameSettings);
#pragma warning restore 618
            }),
            MigrationStep.New(Version.ShaderStrippingSettings, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                data.m_ShaderStrippingSetting.exportShaderVariants = data.m_ExportShaderVariants;
                data.m_ShaderStrippingSetting.shaderVariantLogLevel = data.m_ShaderVariantLogLevel;
                data.m_ShaderStrippingSetting.stripRuntimeDebugShaders= data.m_StripDebugVariants;
#pragma warning restore 618
            }),
            MigrationStep.New(Version.RenderingPathFrameSettings, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                data.m_ObsoleteRenderingPath.GetDefaultFrameSettings(FrameSettingsRenderType.Camera) = data.m_ObsoleteRenderingPathDefaultCameraFrameSettings;
                data.m_ObsoleteRenderingPath.GetDefaultFrameSettings(FrameSettingsRenderType.CustomOrBakedReflection) = data.m_ObsoleteRenderingPathDefaultBakedOrCustomReflectionFrameSettings;
                data.m_ObsoleteRenderingPath.GetDefaultFrameSettings(FrameSettingsRenderType.RealtimeReflection) = data.m_ObsoleteRenderingPathDefaultRealtimeReflectionFrameSettings;
#pragma warning restore 618
            }),
            MigrationStep.New(Version.CustomPostProcessOrdersSettings, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                data.m_CustomPostProcessOrdersSettings.afterPostProcessBlursCustomPostProcesses.AddRange(data.afterPostProcessBlursCustomPostProcesses);
                data.m_CustomPostProcessOrdersSettings.afterPostProcessCustomPostProcesses.AddRange(data.afterPostProcessCustomPostProcesses);
                data.m_CustomPostProcessOrdersSettings.beforePostProcessCustomPostProcesses.AddRange(data.beforePostProcessCustomPostProcesses);
                data.m_CustomPostProcessOrdersSettings.beforeTAACustomPostProcesses.AddRange(data.beforeTAACustomPostProcesses);
                data.m_CustomPostProcessOrdersSettings.beforeTransparentCustomPostProcesses.AddRange(data.beforeTransparentCustomPostProcesses);
#pragma warning restore 618
            }),
            MigrationStep.New(Version.SetUpIncluderRenderPipelineAssetGraphicsSettings, (HDRenderPipelineGlobalSettings data) => data.SetUpRPAssetIncluded()),
            MigrationStep.New(Version.ToRenderPipelineGraphicsSettings, (HDRenderPipelineGlobalSettings data) =>
            {
                MigrateToRenderPipelineGraphicsSettings(data);
            }),
            MigrationStep.New(Version.RenderingLayerMask, (HDRenderPipelineGlobalSettings data) =>
            {
#pragma warning disable 618 // Type or member is obsolete
                if (data.renderingLayerNames == null || data.renderingLayerNames.Length == 0)
                    return;
                
                for (int i = 1; i < data.renderingLayerNames.Length; i++)
                {
                    if (i >= UnityEngine.RenderingLayerMask.GetRenderingLayerCount())
                        RenderPipelineEditorUtility.TryAddRenderingLayerName("");

                    var name = data.renderingLayerNames[i];
                    if(string.IsNullOrWhiteSpace(name))
                        continue;

                    var currentLayerName = UnityEngine.RenderingLayerMask.RenderingLayerToName(i);
                    if (!string.IsNullOrWhiteSpace(currentLayerName))
                        currentLayerName += $" - {name}";
                    else
                        currentLayerName = name;

                    RenderPipelineEditorUtility.TrySetRenderingLayerName(i, currentLayerName);
                }
#pragma warning restore 618 // Type or member is obsolete
            })
        );
        public bool Migrate()
            => k_Migration.Migrate(this);

        bool IMigratableAsset.IsAtLastVersion()
            => m_Version >= MigrationDescription.LastVersion<Version>();

        internal static void MigrateFromHDRPAsset(HDRenderPipelineAsset oldAsset)
        {
            if (instance != null && !instance.Equals(null) && !(instance.m_Version == Version.First))
                return;

            //1. Create the instance or load current one
            HDRenderPipelineGlobalSettings assetToUpgrade = instance;

            if (assetToUpgrade == null || assetToUpgrade.Equals(null))
            {
                assetToUpgrade = RenderPipelineGlobalSettingsUtils.Create<HDRenderPipelineGlobalSettings>(defaultPath);
                EditorGraphicsSettings.SetRenderPipelineGlobalSettingsAsset<HDRenderPipeline>(assetToUpgrade);
            }

            Debug.Assert(assetToUpgrade);

            //2. Migrate obsolete assets (version DefaultSettingsAsAnAsset)
#pragma warning disable 618 // Type or member is obsolete
            assetToUpgrade.m_ObsoleteDefaultVolumeProfile = oldAsset.m_ObsoleteDefaultVolumeProfile;
            assetToUpgrade.m_ObsoleteLookDevVolumeProfile = oldAsset.m_ObsoleteDefaultLookDevProfile;

            assetToUpgrade.m_ObsoleteRenderingPathDefaultCameraFrameSettings                  = oldAsset.m_ObsoleteFrameSettingsMovedToDefaultSettings;
            assetToUpgrade.m_ObsoleteRenderingPathDefaultBakedOrCustomReflectionFrameSettings = oldAsset.m_ObsoleteBakedOrCustomReflectionFrameSettingsMovedToDefaultSettings;
            assetToUpgrade.m_ObsoleteRenderingPathDefaultRealtimeReflectionFrameSettings      = oldAsset.m_ObsoleteRealtimeReflectionFrameSettingsMovedToDefaultSettings;

            assetToUpgrade.beforeTransparentCustomPostProcesses.AddRange(oldAsset.m_ObsoleteBeforeTransparentCustomPostProcesses);
            assetToUpgrade.beforePostProcessCustomPostProcesses.AddRange(oldAsset.m_ObsoleteBeforePostProcessCustomPostProcesses);
            assetToUpgrade.afterPostProcessCustomPostProcesses.AddRange(oldAsset.m_ObsoleteAfterPostProcessCustomPostProcesses);
            assetToUpgrade.beforeTAACustomPostProcesses.AddRange(oldAsset.m_ObsoleteBeforeTAACustomPostProcesses);

            assetToUpgrade.lightLayerName0 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteLightLayerName0;
            assetToUpgrade.lightLayerName1 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteLightLayerName1;
            assetToUpgrade.lightLayerName2 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteLightLayerName2;
            assetToUpgrade.lightLayerName3 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteLightLayerName3;
            assetToUpgrade.lightLayerName4 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteLightLayerName4;
            assetToUpgrade.lightLayerName5 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteLightLayerName5;
            assetToUpgrade.lightLayerName6 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteLightLayerName6;
            assetToUpgrade.lightLayerName7 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteLightLayerName7;

            if (oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteDecalLayerName0 != null)
            {
                assetToUpgrade.decalLayerName0 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteDecalLayerName0;
                assetToUpgrade.decalLayerName1 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteDecalLayerName1;
                assetToUpgrade.decalLayerName2 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteDecalLayerName2;
                assetToUpgrade.decalLayerName3 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteDecalLayerName3;
                assetToUpgrade.decalLayerName4 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteDecalLayerName4;
                assetToUpgrade.decalLayerName5 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteDecalLayerName5;
                assetToUpgrade.decalLayerName6 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteDecalLayerName6;
                assetToUpgrade.decalLayerName7 = oldAsset.currentPlatformRenderPipelineSettings.m_ObsoleteDecalLayerName7;
            }

            assetToUpgrade.m_ShaderVariantLogLevel = (ShaderVariantLogLevel) oldAsset.m_ObsoleteShaderVariantLogLevel;
            assetToUpgrade.lensAttenuationMode = oldAsset.m_ObsoleteLensAttenuation;

            // we need to make sure the old diffusion profile had time to upgrade before moving it away
            if (oldAsset.diffusionProfileSettings != null)
                oldAsset.diffusionProfileSettings.TryToUpgrade();

            int oldSize = oldAsset.m_ObsoleteDiffusionProfileSettingsList?.Length ?? 0;
            System.Array.Resize(ref assetToUpgrade.m_ObsoleteDiffusionProfileSettingsList, oldSize);
            for (int i = 0; i < oldSize; ++i)
                assetToUpgrade.m_ObsoleteDiffusionProfileSettingsList[i] = oldAsset.m_ObsoleteDiffusionProfileSettingsList[i];
#pragma warning restore 618

            //3. Set version to next & Launch remaining of migration
            // If we created it from HDRPAsset, we want to pass it from all migration step that are relevant as copied data are at version First
            assetToUpgrade.m_Version = Version.First; //Step only apply on version older
            for (Version i = Version.First; i <= MigrationDescription.LastVersion<Version>(); ++i)
            {
                if (skipedStepWhenCreatedFromHDRPAsset.Contains(i))
                    continue;

                k_Migration.ExecuteStep(assetToUpgrade, i);
            }
            // Above ExecuteStep will change version. Bring it back to last one.
            assetToUpgrade.m_Version = MigrationDescription.LastVersion<Version>();
            UnityEditor.EditorUtility.SetDirty(assetToUpgrade);
        }

        #region MigrateToRenderPipelineGraphicsSettings
        public static void MigrateToRenderPipelineGraphicsSettings(HDRenderPipelineGlobalSettings data)
        {
            MigrateToShaderStrippingSetting(data);
            MigrateRenderingPathFrameSettings(data);
            MigrateMiscSection(data);
            MigrateCustomPostProcessOrdersSettings(data);
            MigrateDefaultVolumeProfile(data);
            MigrateLookDevVolumeProfile(data);
        }

        private static T GetOrCreateGraphicsSettings<T>(HDRenderPipelineGlobalSettings data)
            where T : class, IRenderPipelineGraphicsSettings, new()
        {
            T settings;

            if (data.TryGet(typeof(T), out var baseSettings))
            {
                settings = baseSettings as T;
            }
            else
            {
                settings = new T();
                data.Add(settings);
            }

            return settings;
        }

        public static void MigrateMiscSection(HDRenderPipelineGlobalSettings data)
        {
#pragma warning disable 618 // Type or member is obsolete
            var diffusionProfileDefaultSettings = GetOrCreateGraphicsSettings<DiffusionProfileDefaultSettings>(data);
            diffusionProfileDefaultSettings.autoRegister = data.autoRegisterDiffusionProfiles;

            var specularFade = GetOrCreateGraphicsSettings<SpecularFadeSettings>(data);
            specularFade.enabled = data.specularFade;

            var colorGrading = GetOrCreateGraphicsSettings<ColorGradingSettings>(data);
            colorGrading.space = data.colorGradingSpace;

            var lens = GetOrCreateGraphicsSettings<LensSettings>(data);
            lens.attenuationMode = data.lensAttenuationMode;

            var analyticDerivative = GetOrCreateGraphicsSettings<AnalyticDerivativeSettings>(data);
            analyticDerivative.debugOutput = data.analyticDerivativeDebugOutput;
            analyticDerivative.emulation = data.analyticDerivativeEmulation;

            var renderGraphSettings = GetOrCreateGraphicsSettings<RenderGraphSettings>(data);
            renderGraphSettings.dynamicRenderPassCullingEnabled = data.rendererListCulling;
#pragma warning restore 618
        }

        public static void MigrateDefaultVolumeProfile(HDRenderPipelineGlobalSettings data)
        {
#pragma warning disable 618 // Type or member is obsolete
            if (data.m_ObsoleteDefaultVolumeProfile == null)
            {
                var defaultVolumeProfileFromResources = GraphicsSettings.GetRenderPipelineSettings<HDRenderPipelineEditorAssets>().defaultVolumeProfile;
                data.m_ObsoleteDefaultVolumeProfile = VolumeUtils.CopyVolumeProfileFromResourcesToAssets(defaultVolumeProfileFromResources);
            }

            var defaultVolumeProfileSettings = GetOrCreateGraphicsSettings<HDRPDefaultVolumeProfileSettings>(data);
            defaultVolumeProfileSettings.volumeProfile = data.m_ObsoleteDefaultVolumeProfile;

            data.m_ObsoleteDefaultVolumeProfile = null; // Discard old reference after it is migrated
#pragma warning restore 618 // Type or member is obsolete
        }

        public static void MigrateLookDevVolumeProfile(HDRenderPipelineGlobalSettings data)
        {
#pragma warning disable 618 // Type or member is obsolete
            if (data.m_ObsoleteLookDevVolumeProfile == null)
            {
                var lookDevProfileFromResources = GetOrCreateGraphicsSettings<HDRenderPipelineEditorAssets>(data).lookDevVolumeProfile;
                data.m_ObsoleteLookDevVolumeProfile = VolumeUtils.CopyVolumeProfileFromResourcesToAssets(lookDevProfileFromResources);
            }

            var lookDevVolumeProfileSettings = GetOrCreateGraphicsSettings<LookDevVolumeProfileSettings>(data);
            lookDevVolumeProfileSettings.volumeProfile = data.m_ObsoleteLookDevVolumeProfile;

            data.m_ObsoleteLookDevVolumeProfile = null; // Discard old reference after it is migrated
#pragma warning restore 618 // Type or member is obsolete
        }

        public static void MigrateToShaderStrippingSetting(HDRenderPipelineGlobalSettings data)
        {
            var shaderStrippingSetting = GetOrCreateGraphicsSettings<ShaderStrippingSetting>(data);

#pragma warning disable 618 // Type or member is obsolete
            shaderStrippingSetting.shaderVariantLogLevel = data.m_ShaderStrippingSetting.shaderVariantLogLevel;
            shaderStrippingSetting.exportShaderVariants = data.m_ShaderStrippingSetting.exportShaderVariants;
            shaderStrippingSetting.stripRuntimeDebugShaders = data.m_ShaderStrippingSetting.stripRuntimeDebugShaders;
#pragma warning restore 618
        }

        static readonly FrameSettingsRenderType[] k_RenderPaths =
            new[] { FrameSettingsRenderType.Camera, FrameSettingsRenderType.CustomOrBakedReflection, FrameSettingsRenderType.RealtimeReflection };

        internal static void MigrateRenderingPathFrameSettings(HDRenderPipelineGlobalSettings data)
        {
            RenderingPathFrameSettings renderingPathFrameSettings = GetOrCreateGraphicsSettings<RenderingPathFrameSettings>(data);

#pragma warning disable 618 // Type or member is obsolete
            foreach (var path in k_RenderPaths)
                renderingPathFrameSettings.GetDefaultFrameSettings(path) = data.m_ObsoleteRenderingPath.GetDefaultFrameSettings(path);
#pragma warning restore 618
        }

        internal static void MigrateCustomPostProcessOrdersSettings(HDRenderPipelineGlobalSettings data)
        {
            CustomPostProcessOrdersSettings customPostProcessOrdersSettings = GetOrCreateGraphicsSettings<CustomPostProcessOrdersSettings>(data);

#pragma warning disable 618 // Type or member is obsolete
            customPostProcessOrdersSettings.beforeTAACustomPostProcesses =
                data.m_CustomPostProcessOrdersSettings.beforeTAACustomPostProcesses;
            customPostProcessOrdersSettings.beforePostProcessCustomPostProcesses =
                data.m_CustomPostProcessOrdersSettings.beforePostProcessCustomPostProcesses;
            customPostProcessOrdersSettings.beforeTransparentCustomPostProcesses =
                data.m_CustomPostProcessOrdersSettings.beforeTransparentCustomPostProcesses;
            customPostProcessOrdersSettings.afterPostProcessBlursCustomPostProcesses =
                data.m_CustomPostProcessOrdersSettings.afterPostProcessBlursCustomPostProcesses;
            customPostProcessOrdersSettings.afterPostProcessCustomPostProcesses =
                data.m_CustomPostProcessOrdersSettings.afterPostProcessCustomPostProcesses;
#pragma warning restore 618
        }


        #endregion

#endif
    }
}