using UnityEngine;
using UnityEngine.Rendering;

namespace UnityEditor.Experimental.Rendering.LightweightPipeline
{
    public static class LightweightShaderHelper
    {
        public static void SetMaterialBlendMode(Material material)
        {
            UpgradeBlendMode mode = (UpgradeBlendMode) material.GetFloat("_Mode");
            switch (mode)
            {
                case UpgradeBlendMode.Opaque:
                    material.SetOverrideTag("RenderType", "");
                    material.SetInt("_SrcBlend", (int) UnityEngine.Rendering.BlendMode.One);
                    material.SetInt("_DstBlend", (int) UnityEngine.Rendering.BlendMode.Zero);
                    material.SetInt("_ZWrite", 1);
                    SetKeyword(material, "_ALPHATEST_ON", false);
                    SetKeyword(material, "_ALPHABLEND_ON", false);
                    material.renderQueue = -1;
                    break;

                case UpgradeBlendMode.Cutout:
                    material.SetOverrideTag("RenderType", "Transparent");
                    material.SetInt("_SrcBlend", (int) UnityEngine.Rendering.BlendMode.One);
                    material.SetInt("_DstBlend", (int) UnityEngine.Rendering.BlendMode.Zero);
                    material.SetInt("_ZWrite", 1);
                    SetKeyword(material, "_ALPHATEST_ON", true);
                    SetKeyword(material, "_ALPHABLEND_ON", false);
                    material.renderQueue = (int) RenderQueue.AlphaTest;
                    break;

                case UpgradeBlendMode.Alpha:
                    material.SetOverrideTag("RenderType", "Transparent");
                    material.SetInt("_SrcBlend", (int) UnityEngine.Rendering.BlendMode.SrcAlpha);
                    material.SetInt("_DstBlend", (int) UnityEngine.Rendering.BlendMode.OneMinusSrcAlpha);
                    material.SetInt("_ZWrite", 0);
                    SetKeyword(material, "_ALPHATEST_ON", false);
                    SetKeyword(material, "_ALPHABLEND_ON", true);
                    material.renderQueue = (int) RenderQueue.Transparent;
                    break;
            }
        }

        public static void SetKeyword(Material material, string keyword, bool enable)
        {
            if (enable)
                material.EnableKeyword(keyword);
            else
                material.DisableKeyword(keyword);
        }
    }
}