using XCEngine;
using XCEngine.Rendering;

namespace XCEngine.Rendering.Universal
{
    public abstract class ScriptableRenderPass
    {
        protected ScriptableRenderPass()
        {
        }

        public RenderPassEvent renderPassEvent { get; protected set; } =
            RenderPassEvent.BeforeRenderingOpaques;

        public virtual bool SupportsStage(
            CameraFrameStage stage)
        {
            CameraFrameStage resolvedStage;
            return TryResolveStage(
                renderPassEvent,
                out resolvedStage) &&
                resolvedStage == stage;
        }

        internal bool Record(
            ScriptableRenderContext context,
            RenderingData renderingData)
        {
            return RecordRenderGraph(
                context,
                renderingData);
        }

        protected abstract bool RecordRenderGraph(
            ScriptableRenderContext context,
            RenderingData renderingData);

        internal static bool TryResolveStage(
            RenderPassEvent passEvent,
            out CameraFrameStage stage)
        {
            switch (passEvent)
            {
                case RenderPassEvent.BeforeRenderingOpaques:
                case RenderPassEvent.RenderOpaques:
                case RenderPassEvent.AfterRenderingOpaques:
                case RenderPassEvent.BeforeRenderingSkybox:
                case RenderPassEvent.RenderSkybox:
                case RenderPassEvent.AfterRenderingSkybox:
                case RenderPassEvent.BeforeRenderingTransparents:
                case RenderPassEvent.RenderTransparents:
                case RenderPassEvent.AfterRenderingTransparents:
                    stage = CameraFrameStage.MainScene;
                    return true;
                case RenderPassEvent.BeforeRenderingPostProcessing:
                case RenderPassEvent.AfterRenderingPostProcessing:
                    stage = CameraFrameStage.PostProcess;
                    return true;
                case RenderPassEvent.BeforeRenderingFinalOutput:
                case RenderPassEvent.AfterRenderingFinalOutput:
                    stage = CameraFrameStage.FinalOutput;
                    return true;
                default:
                    stage = CameraFrameStage.MainScene;
                    return false;
            }
        }
    }
}