using UnityEngine;

namespace UnityEditor.Rendering.HighDefinition
{
    /// <summary>
    /// The UI block that displays distortion properties for materials.
    /// </summary>
    public class DistortionUIBlock : MaterialUIBlock
    {
        internal static class Styles
        {
            public static GUIContent distortionEnableText = new GUIContent("Distortion", "When enabled, HDRP processes distortion for this Material.");
            public static GUIContent distortionOnlyText = new GUIContent("Distortion Only", "When enabled, HDRP only uses this Material to render distortion.");
            public static GUIContent distortionDepthTestText = new GUIContent("Distortion Depth Test", "When enabled, HDRP calculates a depth test for distortion, clipping the distortion contribution if it is occluded.");
            public static GUIContent distortionVectorMapText = new GUIContent("Distortion Vector Map (RGB)", "Specifies the Vector Map HDRP used for the distortion effect.\n\nDistortion 2D vector (RG) and Blur amount (B)\n\nHDRP first applies the scale as a multiplicative, and then the bias additively, to the distortion vector only; not the blur amount.");
            public static GUIContent distortionBlendModeText = new GUIContent("Distortion Blend Mode", "Specifies the mode HDRP uses to calculate distortion.");
            public static GUIContent distortionScaleText = new GUIContent("Distortion Scale", "Sets the scale HDRP applies to the Distortion Vector Map.");
            public static GUIContent distortionBlurScaleText = new GUIContent("Distortion Blur Scale", "Sets the scale HDRP applies to the distortion blur effect.");
            public static GUIContent distortionBlurRemappingText = new GUIContent("Distortion Blur Remapping", "Controls a remap for the Distortion Blur effect.");
            public static GUIContent distortionRoughInfoText = new GUIContent("Blur parameters will have an effect on the distortion if the Rough Distortion Frame Setting is enabled on the target camera.");
        }

        MaterialProperty distortionEnable = null;
        const string kDistortionEnable = "_DistortionEnable";
        MaterialProperty distortionOnly = null;
        const string kDistortionOnly = "_DistortionOnly";
        MaterialProperty distortionDepthTest = null;
        const string kDistortionDepthTest = "_DistortionDepthTest";
        MaterialProperty distortionVectorMap = null;
        const string kDistortionVectorMap = "_DistortionVectorMap";
        MaterialProperty distortionBlendMode = null;
        const string kDistortionBlendMode = "_DistortionBlendMode";
        MaterialProperty distortionScale = null;
        const string kDistortionScale = "_DistortionScale";
        MaterialProperty distortionVectorScale = null;
        const string kDistortionVectorScale = "_DistortionVectorScale";
        MaterialProperty distortionVectorBias = null;
        const string kDistortionVectorBias = "_DistortionVectorBias";
        MaterialProperty distortionBlurScale = null;
        const string kDistortionBlurScale = "_DistortionBlurScale";
        MaterialProperty distortionBlurRemapMin = null;
        const string kDistortionBlurRemapMin = "_DistortionBlurRemapMin";
        MaterialProperty distortionBlurRemapMax = null;
        const string kDistortionBlurRemapMax = "_DistortionBlurRemapMax";

        /// <summary>
        /// Loads the material properties for the block.
        /// </summary>
        public override void LoadMaterialProperties()
        {
            distortionEnable = FindProperty(kDistortionEnable, false);
            distortionOnly = FindProperty(kDistortionOnly, false);
            distortionDepthTest = FindProperty(kDistortionDepthTest, false);
            distortionVectorMap = FindProperty(kDistortionVectorMap, false);
            distortionBlendMode = FindProperty(kDistortionBlendMode, false);
            distortionScale = FindProperty(kDistortionScale, false);
            distortionVectorScale = FindProperty(kDistortionVectorScale, false);
            distortionVectorBias = FindProperty(kDistortionVectorBias, false);
            distortionBlurScale = FindProperty(kDistortionBlurScale, false);
            distortionBlurRemapMin = FindProperty(kDistortionBlurRemapMin, false);
            distortionBlurRemapMax = FindProperty(kDistortionBlurRemapMax, false);
        }

        /// <summary>
        /// Renders the distortion properties.
        /// </summary>
        public override void OnGUI()
        {
            if (distortionEnable != null)
            {
                materialEditor.ShaderProperty(distortionEnable, Styles.distortionEnableText);

                if (distortionEnable.floatValue == 1.0f)
                {
                    EditorGUILayout.HelpBox(Styles.distortionRoughInfoText.text, MessageType.Info, true);
                    EditorGUI.indentLevel++;
                    materialEditor.ShaderProperty(distortionBlendMode, Styles.distortionBlendModeText);
                    if (distortionOnly != null)
                        materialEditor.ShaderProperty(distortionOnly, Styles.distortionOnlyText);
                    materialEditor.ShaderProperty(distortionDepthTest, Styles.distortionDepthTestText);

                    EditorGUI.indentLevel++;
                    materialEditor.TexturePropertySingleLine(Styles.distortionVectorMapText, distortionVectorMap, distortionVectorScale, distortionVectorBias);
                    EditorGUI.indentLevel++;

                    if (distortionVectorMap.textureValue != null)
                        materialEditor.TextureScaleOffsetProperty(distortionVectorMap);

                    materialEditor.ShaderProperty(distortionScale, Styles.distortionScaleText);

                    EditorGUI.BeginChangeCheck();
                    materialEditor.ShaderProperty(distortionBlurScale, Styles.distortionBlurScaleText);
                    if (EditorGUI.EndChangeCheck())
                        distortionBlurScale.floatValue = Mathf.Max(0f, distortionBlurScale.floatValue);

                    float remapMin = distortionBlurRemapMin.floatValue;
                    float remapMax = distortionBlurRemapMax.floatValue;
                    EditorGUI.BeginChangeCheck();
                    EditorGUILayout.MinMaxSlider(Styles.distortionBlurRemappingText, ref remapMin, ref remapMax, 0.0f, 1.0f);
                    if (EditorGUI.EndChangeCheck())
                    {
                        distortionBlurRemapMin.floatValue = remapMin;
                        distortionBlurRemapMax.floatValue = remapMax;
                    }
                    EditorGUI.indentLevel--;

                    EditorGUI.indentLevel--;

                    EditorGUI.indentLevel--;
                }
            }
        }
    }
}