using System;

namespace UnityEngine.Rendering.HighDefinition
{
    /// <summary>
    /// HDRI Sky Volume Component.
    /// This component setups HDRI sky for rendering.
    /// </summary>
    [VolumeComponentMenu("Sky/HDRI Sky")]
    [SupportedOnRenderPipeline(typeof(HDRenderPipelineAsset))]
    [SkyUniqueID((int)SkyType.HDRI)]
    [HDRPHelpURL("create-an-hdri-sky")]
    public partial class HDRISky : SkySettings
    {
        /// <summary>
        /// Distortion Mode.
        /// </summary>
        public enum DistortionMode
        {
            /// <summary>No distortion.</summary>
            None,
            /// <summary>Procedural distortion.</summary>
            Procedural,
            /// <summary>Distortion from a flowmap.</summary>
            Flowmap,
        }

        /// <summary>Cubemap used to render the HDRI sky.</summary>
        [Tooltip("Specify the cubemap HDRP uses to render the sky.")]
        public CubemapParameter hdriSky = new CubemapParameter(null);
        /// <summary>Distortion mode.</summary>
        [Tooltip("Distortion mode to simulate sky movement.\nIn Scene View, requires Always Refresh to be enabled.")]
        public VolumeParameter<DistortionMode> distortionMode = new VolumeParameter<DistortionMode>();
        /// <summary>Texture used to distort the uv for the HDRI sky.</summary>
        [Tooltip("Specify the flowmap HDRP uses for sky distortion (in LatLong layout).")]
        public Texture2DParameter flowmap = new Texture2DParameter(null);
        /// <summary>Enable to affect only the upper part of the sky.</summary>
        [Tooltip("Check this box if the flowmap covers only the upper part of the sky.")]
        public BoolParameter upperHemisphereOnly = new BoolParameter(true);
        /// <summary>Direction of the distortion. This value can be relative to the Global Wind Orientation defined in the Visual Environment.</summary>
        public WindOrientationParameter scrollOrientation = new WindOrientationParameter();
        /// <summary>Speed of the distortion. This value can be relative to the Global Wind Speed defined in the Visual Environment.</summary>
        public WindSpeedParameter scrollSpeed = new WindSpeedParameter();
        /// <summary>Sets the initial rotation of the sun to allow us to rotate the sun with the sky if the sun is locked</summary>
        public FloatParameter sunInitialRotation = new FloatParameter(float.NegativeInfinity);
        /// <summary> Locks the sun to the backplate rotation</summary>
        [Tooltip("Enable to have the sun locked to the rotation")]
        public BoolParameter lockSun = new BoolParameter(false);
        /// <summary>Enable Backplate to have it visible.</summary>
        [AdditionalProperty]
        [Tooltip("Enable or disable the backplate.")]
        public BoolParameter enableBackplate = new BoolParameter(false);
        /// <summary>Backplate Type {Disc, Rectangle, Ellipse, Infinite (Plane)}.</summary>
        [AdditionalProperty]
        [Tooltip("Backplate type.")]
        public BackplateTypeParameter backplateType = new BackplateTypeParameter(BackplateType.Disc);
        /// <summary>Define the ground level of the Backplate.</summary>
        [AdditionalProperty]
        [Tooltip("Define the ground level of the Backplate.")]
        public FloatParameter groundLevel = new FloatParameter(0.0f);
        /// <summary>Extent of the Backplate (if circle only the X value is considered).</summary>
        [AdditionalProperty]
        [Tooltip("Extent of the Backplate (if circle only the X value is considered).")]
        public Vector2Parameter scale = new Vector2Parameter(Vector2.one * 32.0f);
        /// <summary>Backplate's projection distance to varying the cubemap projection on the plate.</summary>
        [AdditionalProperty]
        [Tooltip("Backplate's projection distance to varying the cubemap projection on the plate.")]
        public MinFloatParameter projectionDistance = new MinFloatParameter(16.0f, 1e-7f);
        /// <summary>Backplate rotation parameter for the geometry.</summary>
        [AdditionalProperty]
        [Tooltip("Backplate rotation parameter for the geometry.")]
        public ClampedFloatParameter plateRotation = new ClampedFloatParameter(0.0f, 0.0f, 360.0f);
        /// <summary>Backplate rotation parameter for the projected texture.</summary>
        [AdditionalProperty]
        [Tooltip("Backplate rotation parameter for the projected texture.")]
        public ClampedFloatParameter plateTexRotation = new ClampedFloatParameter(0.0f, 0.0f, 360.0f);
        /// <summary>Backplate projection offset on the plane.</summary>
        [AdditionalProperty]
        [Tooltip("Backplate projection offset on the plane.")]
        public Vector2Parameter plateTexOffset = new Vector2Parameter(Vector2.zero);
        /// <summary>Backplate blend parameter to blend the edge of the backplate with the background.</summary>
        [AdditionalProperty]
        [Tooltip("Backplate blend parameter to blend the edge of the backplate with the background.")]
        public ClampedFloatParameter blendAmount = new ClampedFloatParameter(0.0f, 0.0f, 100.0f);
        /// <summary>Backplate Shadow Tint projected on the plane.</summary>
        [AdditionalProperty]
        [Tooltip("Backplate Shadow Tint projected on the plane.")]
        public ColorParameter shadowTint = new ColorParameter(Color.grey);
        /// <summary>Allow backplate to receive shadow from point light.</summary>
        [AdditionalProperty]
        [Tooltip("Allow backplate to receive shadow from point light.")]
        public BoolParameter pointLightShadow = new BoolParameter(false);
        /// <summary>Allow backplate to receive shadow from directional light.</summary>
        [AdditionalProperty]
        [Tooltip("Allow backplate to receive shadow from directional light.")]
        public BoolParameter dirLightShadow = new BoolParameter(false);
        /// <summary>Allow backplate to receive shadow from Area light.</summary>
        [AdditionalProperty]
        [Tooltip("Allow backplate to receive shadow from Area light.")]
        public BoolParameter rectLightShadow = new BoolParameter(false);

        /// <summary>
        /// Unity calls this method when it loads the class.
        /// </summary>
        protected override void OnEnable()
        {
            base.OnEnable();

            // This is kind of a migration step, as on previous HDRP versions, HDRI sky editor
            // didn't correctly set these values
            upperHemisphereLuxValue.overrideState = hdriSky.overrideState;
            upperHemisphereLuxColor.overrideState = hdriSky.overrideState;
        }

        /// <summary>
        /// Returns the hash code of the HDRI sky parameters.
        /// </summary>
        /// <returns>The hash code of the HDRI sky parameters.</returns>
        public override int GetHashCode()
        {
            int hash = base.GetHashCode();

            unchecked
            {
#if UNITY_2019_3 // In 2019.3, when we call GetHashCode on a VolumeParameter it generate garbage (due to the boxing of the generic parameter)
                hash = hdriSky.value != null ? hash * 23 + hdriSky.value.GetHashCode() : hash;
                hash = flowmap.value != null ? hash * 23 + flowmap.value.GetHashCode() : hash;
                hash = hash * 23 + enableDistortion.value.GetHashCode();
                hash = hash * 23 + procedural.value.GetHashCode();
                hash = hash * 23 + upperHemisphereOnly.value.GetHashCode();
                hash = hash * 23 + scrollDirection.value.GetHashCode();
                hash = hash * 23 + scrollSpeed.value.GetHashCode();

                hash = hash * 23 + enableBackplate.value.GetHashCode();
                hash = hash * 23 + backplateType.value.GetHashCode();
                hash = hash * 23 + groundLevel.value.GetHashCode();
                hash = hash * 23 + scale.value.GetHashCode();
                hash = hash * 23 + projectionDistance.value.GetHashCode();
                hash = hash * 23 + plateRotation.value.GetHashCode();
                hash = hash * 23 + plateTexRotation.value.GetHashCode();
                hash = hash * 23 + plateTexOffset.value.GetHashCode();
                hash = hash * 23 + blendAmount.value.GetHashCode();
                hash = hash * 23 + shadowTint.value.GetHashCode();
                hash = hash * 23 + pointLightShadow.value.GetHashCode();
                hash = hash * 23 + dirLightShadow.value.GetHashCode();
                hash = hash * 23 + rectLightShadow.value.GetHashCode();

                hash = hdriSky.value != null ? hash * 23 + hdriSky.overrideState.GetHashCode() : hash;
                hash = flowmap.value != null ? hash * 23 + flowmap.overrideState.GetHashCode() : hash;
                hash = hash * 23 + enableDistortion.overrideState.GetHashCode();
                hash = hash * 23 + procedural.overrideState.GetHashCode();
                hash = hash * 23 + upperHemisphereOnly.overrideState.GetHashCode();
                hash = hash * 23 + scrollDirection.overrideState.GetHashCode();
                hash = hash * 23 + scrollSpeed.overrideState.GetHashCode();

                hash = hash * 23 + enableBackplate.overrideState.GetHashCode();
                hash = hash * 23 + backplateType.overrideState.GetHashCode();
                hash = hash * 23 + groundLevel.overrideState.GetHashCode();
                hash = hash * 23 + scale.overrideState.GetHashCode();
                hash = hash * 23 + projectionDistance.overrideState.GetHashCode();
                hash = hash * 23 + plateRotation.overrideState.GetHashCode();
                hash = hash * 23 + plateTexRotation.overrideState.GetHashCode();
                hash = hash * 23 + plateTexOffset.overrideState.GetHashCode();
                hash = hash * 23 + blendAmount.overrideState.GetHashCode();
                hash = hash * 23 + shadowTint.overrideState.GetHashCode();
                hash = hash * 23 + pointLightShadow.overrideState.GetHashCode();
                hash = hash * 23 + dirLightShadow.overrideState.GetHashCode();
                hash = hash * 23 + rectLightShadow.overrideState.GetHashCode();
#else
                hash = hash * 23 + hdriSky.GetHashCode();
                hash = hash * 23 + flowmap.GetHashCode();
                hash = hash * 23 + distortionMode.GetHashCode();
                hash = hash * 23 + upperHemisphereOnly.GetHashCode();
                hash = hash * 23 + scrollOrientation.GetHashCode();
                hash = hash * 23 + scrollSpeed.GetHashCode();

                hash = hash * 23 + enableBackplate.GetHashCode();
                hash = hash * 23 + backplateType.GetHashCode();
                hash = hash * 23 + groundLevel.GetHashCode();
                hash = hash * 23 + scale.GetHashCode();
                hash = hash * 23 + projectionDistance.GetHashCode();
                hash = hash * 23 + plateRotation.GetHashCode();
                hash = hash * 23 + plateTexRotation.GetHashCode();
                hash = hash * 23 + plateTexOffset.GetHashCode();
                hash = hash * 23 + blendAmount.GetHashCode();
                hash = hash * 23 + shadowTint.GetHashCode();
                hash = hash * 23 + pointLightShadow.GetHashCode();
                hash = hash * 23 + dirLightShadow.GetHashCode();
                hash = hash * 23 + rectLightShadow.GetHashCode();
#endif
            }

            return hash;
        }

        /// <summary>
        /// Determines if the SkySettings is significantly divergent from another. This is going to be used to determine whether
        /// to reset completely the ambient probe instead of using previous one when waiting for current data upon changes.
        /// In addition to the checks done with the base function, this HDRISky override checks whether the cubemap parameter
        /// has changed if both settings are HDRISky.
        /// </summary>
        /// <param name="otherSettings">The settings to compare with.</param>
        /// <returns>Whether the settings are deemed very different.</returns>
        public override bool SignificantlyDivergesFrom(SkySettings otherSettings)
        {
            HDRISky otherHdriSkySettings = otherSettings as HDRISky;

            return base.SignificantlyDivergesFrom(otherSettings) || hdriSky.value != otherHdriSkySettings.hdriSky.value;
        }

        /// <summary>
        /// Returns HDRISkyRenderer type.
        /// </summary>
        /// <returns>HDRISkyRenderer type.</returns>
        public override Type GetSkyRendererType() { return typeof(HDRISkyRenderer); }
    }
}