using UnityEditor;
using UnityEditor.Rendering;
using UnityEngine;

namespace CiroContinisio.ToonShader.Editor
{
    public class ToonShaderGUI : ShaderGUI 
    {
        private enum ShadingStyle
        {
            SkinAndTextiles,
            HairAndMetal,
        }
        private ShadingStyle _shadingStyle;

        private bool _toonPropsVisible = true;
        private bool _emission;

        private const string SkinKeyword = "_SHADING_STYLE_SKIN_AND_TEXTILES";
        private const string HairKeyword = "_SHADING_STYLE_HAIR_AND_METAL";

        public override void OnGUI (MaterialEditor materialEditor, MaterialProperty[] properties)
        {
            Material targetMaterial = materialEditor.target as Material;

            //======= Base Properties
        
            GUILayout.Label("Base properties", EditorStyles.boldLabel);
            EditorGUI.indentLevel++;
        
            materialEditor.TextureProperty(FindProperty("_BaseMap", properties), "Base map");
            materialEditor.ColorProperty(FindProperty("_BaseColor", properties), "Tint");
            materialEditor.TextureProperty(FindProperty("_NormalMap", properties), "Normal map");
        
            //Emission property
            bool emissionPreviousValue = _emission;
            _emission = DrawEmissionToggle(materialEditor, FindProperty("_UseEmission", properties));
            if (_emission)
            {
                EditorGUI.indentLevel++;
                materialEditor.TextureProperty(FindProperty("_EmissionMap", properties), "Emission map");
                materialEditor.ColorProperty(FindProperty("_EmissionColor", properties), "Emission tint");
                EditorGUI.indentLevel--;
                if (emissionPreviousValue != _emission)
                {
                    targetMaterial.EnableKeyword("_EMISSION");
                    targetMaterial.globalIlluminationFlags = MaterialGlobalIlluminationFlags.None;
                }
            }
            else
            {
                if (emissionPreviousValue != _emission)
                {
                    targetMaterial.DisableKeyword("_EMISSION");
                    targetMaterial.globalIlluminationFlags = MaterialGlobalIlluminationFlags.EmissiveIsBlack;
                }
            }

            materialEditor.RangeProperty(FindProperty("_Smoothness", properties), "Smoothness");
            materialEditor.ColorProperty(FindProperty("_SpecularColor", properties), "Specular color");
        
            EditorGUI.indentLevel--;
        
            //======= Shading style
        
            EditorGUILayout.Space(4f);
            EditorGUILayout.LabelField("Shading style", EditorStyles.boldLabel);
            EditorGUILayout.Space(-3f);
            EditorGUI.indentLevel++;
        
            string[] options = {"Skin or Textiles", "Hair or Metal"};
            _shadingStyle = (ShadingStyle)materialEditor.PopupShaderProperty(FindProperty("_SHADING_STYLE", properties), new GUIContent("Material"), options);
        
            switch (_shadingStyle)
            {
                case ShadingStyle.SkinAndTextiles:
                    materialEditor.RangeProperty(FindProperty("_PaintbrushStrokesSize", properties), "Paintbrush strokes size");
                    materialEditor.RangeProperty(FindProperty("_PaintbrushStrokesAngle", properties), "Paintbrush strokes angle");
                    break;
                case ShadingStyle.HairAndMetal:
                    materialEditor.RangeProperty(FindProperty("_SpecularNoiseSize", properties), "Specular noise size");
                    materialEditor.RangeProperty(FindProperty("_ExtraBandThickness", properties), "Extra band thickness");
                    break;
            }
        
            targetMaterial.EnableKeyword(_shadingStyle == ShadingStyle.SkinAndTextiles ? SkinKeyword : HairKeyword);
            targetMaterial.DisableKeyword(_shadingStyle == ShadingStyle.SkinAndTextiles ? HairKeyword : SkinKeyword);
        
            EditorGUI.indentLevel--;
        
            //======= Toon Properties
        
            EditorGUILayout.Space(4f);
            _toonPropsVisible = EditorGUILayout.Foldout(_toonPropsVisible, "Toon properties", EditorStyles.foldoutHeader);
            if (_toonPropsVisible)
            {
                EditorGUI.indentLevel++;
                materialEditor.RangeProperty(FindProperty("_ToonCutoffPoint", properties), "Toon cutoff");
                materialEditor.RangeProperty(FindProperty("_AdditionalLightCutoffPoint", properties), "Additional light cutoff");
                materialEditor.RangeProperty(FindProperty("_ShadowsFloor", properties), "Shadows floor value");
                materialEditor.RangeProperty(FindProperty("_StrongRimStrength", properties), "Strong rim strength");
                EditorGUI.indentLevel--;
            }
        }

        private bool DrawEmissionToggle(MaterialEditor materialEditor, MaterialProperty prop)
        {
            bool value = (prop.floatValue != 0.0f);

            EditorGUI.BeginChangeCheck();
            EditorGUI.showMixedValue = prop.hasMixedValue;

            // Show the toggle control
            value = EditorGUILayout.Toggle("Emission", value);

            EditorGUI.showMixedValue = false;
            if (EditorGUI.EndChangeCheck())
            {
                prop.floatValue = value ? 1.0f : 0.0f;
            }

            return value && !prop.hasMixedValue;
        }
    }
}