using UnityEditor;
using UnityEngine;
using System;
using System.Reflection;

namespace Project.Editor
{
    internal static class Urp3DWebGlMigration
    {
        private const string MigrationVersionKey = "Project.URP3DWebGLMigration.v1";
        private const string SettingsFolder = "Assets/Settings";
        private const string PipelineAssetPath = SettingsFolder + "/UniversalRP.asset";
        private const string RendererAssetPath = SettingsFolder + "/UniversalRenderer.asset";
        private const string OldRendererAssetPath = SettingsFolder + "/Renderer2D.asset";
        private const string UniversalRuntimeAssembly = "Unity.RenderPipelines.Universal.Runtime";
        private const string PipelineAssetTypeName = "UnityEngine.Rendering.Universal.UniversalRenderPipelineAsset";
        private const string RendererDataTypeName = "UnityEngine.Rendering.Universal.UniversalRendererData";

        [InitializeOnLoadMethod]
        private static void RunOnLoad()
        {
            EditorApplication.delayCall += TryMigrate;
        }

        [MenuItem("Tools/Rendering/Run URP 3D WebGL Migration")]
        private static void RunFromMenu()
        {
            SessionState.EraseString(MigrationVersionKey);
            TryMigrate();
        }

        private static void TryMigrate()
        {
            if (SessionState.GetString(MigrationVersionKey, string.Empty) == "done")
            {
                return;
            }

            SessionState.SetString(MigrationVersionKey, "done");

            Type pipelineAssetType = Type.GetType($"{PipelineAssetTypeName}, {UniversalRuntimeAssembly}");
            Type rendererDataType = Type.GetType($"{RendererDataTypeName}, {UniversalRuntimeAssembly}");
            if (pipelineAssetType == null || rendererDataType == null)
            {
                return;
            }

            UnityEngine.Object pipelineAsset = AssetDatabase.LoadAssetAtPath(PipelineAssetPath, pipelineAssetType);
            if (pipelineAsset == null)
            {
                return;
            }

            UnityEngine.Object rendererData = AssetDatabase.LoadAssetAtPath(RendererAssetPath, rendererDataType);
            if (rendererData == null)
            {
                rendererData = ScriptableObject.CreateInstance(rendererDataType);
                AssetDatabase.CreateAsset(rendererData, RendererAssetPath);
                InvokeNonPublicMethod(rendererData, "OnValidate");
            }

            SerializedObject pipelineObject = new SerializedObject(pipelineAsset);
            pipelineObject.FindProperty("m_RendererType").intValue = 0;
            pipelineObject.FindProperty("m_RendererData").objectReferenceValue = rendererData;

            SerializedProperty rendererList = pipelineObject.FindProperty("m_RendererDataList");
            rendererList.arraySize = 1;
            rendererList.GetArrayElementAtIndex(0).objectReferenceValue = rendererData;
            pipelineObject.FindProperty("m_DefaultRendererIndex").intValue = 0;
            pipelineObject.ApplyModifiedPropertiesWithoutUndo();

            EditorUtility.SetDirty(rendererData);
            EditorUtility.SetDirty(pipelineAsset);
            AssetDatabase.SaveAssets();

            if (AssetDatabase.LoadAssetAtPath<UnityEngine.Object>(OldRendererAssetPath) != null)
            {
                AssetDatabase.DeleteAsset(OldRendererAssetPath);
            }
        }

        private static void InvokeNonPublicMethod(object target, string methodName)
        {
            target.GetType()
                .GetMethod(methodName, BindingFlags.Instance | BindingFlags.NonPublic)
                ?.Invoke(target, null);
        }
    }
}