//////////////////////////////////////////////////////
// Shader Packager
// Copyright (c)2021 Jason Booth
//////////////////////////////////////////////////////

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
#if UNITY_2020_2_OR_NEWER
using UnityEditor.AssetImporters;
#else
using UnityEditor.Experimental.AssetImporters;
#endif
using System.IO;

namespace JBooth.MicroVerseCore.ShaderPackager
{

   [ScriptedImporter(0, ShaderPackageImporter.k_FileExtension)]
   public class ShaderPackageImporter : ScriptedImporter
   {
      public const string k_FileExtension = ".microversepack";

      public override void OnImportAsset(AssetImportContext ctx)
      {
         
         string fileContent = File.ReadAllText(ctx.assetPath);
         var package = ObjectFactory.CreateInstance<ShaderPackage>();

         if (!string.IsNullOrEmpty(fileContent))
         {
            try
            {
                EditorJsonUtility.FromJsonOverwrite(fileContent, package);
            }
            catch
            {

            }
         }

         if (package.entries == null)
         {
            package.entries = new List<ShaderPackage.Entry>();
         }

#if __BETTERSHADERS__ && __MICROVERSE_DEVMODE__
         if (package.betterShader != null)
         {
            package.betterShaderPath = AssetDatabase.GetAssetPath(package.betterShader);
         }
#endif

            package.Pack(false);

#if __BETTERSHADERS__ && __MICROVERSE_DEVMODE__
         if (package.betterShader != null)
         {
               ctx.DependsOnSourceAsset(package.betterShaderPath);
         }
         
#endif

            foreach (var e in package.entries)
         {
            if (e.shader != null)
            {
               ctx.DependsOnSourceAsset(AssetDatabase.GetAssetPath(e.shader));
            }
         }
         
         string shaderSrc = package.GetShaderSrc();
         if (shaderSrc == null)
         {
            Debug.LogError("No Shader for this platform and SRP provided");
            // maybe make an error shader here?
            return;
         }

         Shader shader = ShaderUtil.CreateShaderAsset(ctx, shaderSrc, false);

         ctx.AddObjectToAsset("MainAsset", shader);
         ctx.SetMainObject(shader);
      }


   }
}