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

public class OutlineRenderFeature : ScriptableRendererFeature
{
    class OutlinePass : ScriptableRenderPass
    {
        private RTHandle tempColorTexture;
        private Material outlineMaterial;
        private RTHandle cameraTarget;

        public OutlinePass(Material material)
        {
            outlineMaterial = material;
        }

        public override void OnCameraSetup(CommandBuffer cmd, ref RenderingData renderingData)
        {
            RenderTextureDescriptor descriptor = renderingData.cameraData.cameraTargetDescriptor;
            descriptor.depthBufferBits = 0; // No need for depth buffer
            tempColorTexture = RTHandles.Alloc(descriptor, name: "_TemporaryColorTexture");

            ConfigureTarget(tempColorTexture);
        }

        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
        {
            if (outlineMaterial == null) return;

            CommandBuffer cmd = CommandBufferPool.Get("Outline Pass");
            cameraTarget = renderingData.cameraData.renderer.cameraColorTargetHandle; // ✅ Safe reference to camera color target

            // Copy to temporary texture
            Blit(cmd, cameraTarget, tempColorTexture);

            // Apply outline effect and blit back
            Blit(cmd, tempColorTexture, cameraTarget, outlineMaterial);

            context.ExecuteCommandBuffer(cmd);
            CommandBufferPool.Release(cmd);
        }

        public override void OnCameraCleanup(CommandBuffer cmd)
        {
            if (tempColorTexture != null)
            {
                RTHandles.Release(tempColorTexture);
                tempColorTexture = null;
            }
        }
    }

    [SerializeField] private Material outlineMaterial;
    private OutlinePass outlinePass;

    public override void Create()
    {
        outlinePass = new OutlinePass(outlineMaterial)
        {
            renderPassEvent = RenderPassEvent.AfterRenderingOpaques // ✅ Executes after opaque objects
        };
    }

    public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
    {
        if (outlinePass != null)
        {
            renderer.EnqueuePass(outlinePass);
        }
    }
}