using System;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

public class SceneEffect : MonoBehaviour
{
    public RenderPassEvent injectionPoint = RenderPassEvent.BeforeRendering;

    [Serializable]
    class Settings
    {
        public GradientTexture ShadowRemapTex;
    }
    [SerializeField]
    private Settings settings;
    SetupPass pass;
    private void OnEnable()
    {
        pass = new(settings);
        pass.renderPassEvent = injectionPoint;
        RenderPipelineManager.beginCameraRendering += OnBeginCamera;
    }

    private void OnDisable()
    {
        RenderPipelineManager.beginCameraRendering -= OnBeginCamera;
    }


    private void OnBeginCamera(ScriptableRenderContext context, Camera cam)
    {
        if (pass == null)
        {
            return;
        }

        if (cam.cameraType != CameraType.Game && cam.cameraType != CameraType.SceneView)
        { 
            return; 
        }

        cam.GetUniversalAdditionalCameraData().scriptableRenderer.EnqueuePass(pass);
    }

    private class SetupPass : ScriptableRenderPass
    {
        const string ShadowRemap = "_ShadowRemapON";
        private Settings settings;

        public SetupPass(Settings settings)
        {
            this.settings = settings;
        }

        public override void FrameCleanup(CommandBuffer cmd)
        {
            cmd.DisableShaderKeyword(ShadowRemap);
        }

        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
        {
            var cmd = CommandBufferPool.Get("DissolveEffect");
            cmd.EnableShaderKeyword(ShadowRemap);
            cmd.SetGlobalTexture("_ShadowRemap", settings.ShadowRemapTex.GetTexture());
            context.ExecuteCommandBuffer(cmd);
            cmd.Clear();
        }
    }
}