using XCEngine;
using XCEngine.Rendering;
using XCEngine.Rendering.RenderGraphModule;

namespace XCEngine.Rendering.Universal
{
    public sealed class DrawObjectsPass : ScriptableRenderPass
    {
        private RendererListDesc m_rendererListDesc =
            RendererListDesc.CreateDefault(
                RendererListType.Opaque);
        private DrawingSettings m_drawingSettings =
            DrawingSettings.CreateDefault();

        public DrawObjectsPass(
            RenderPassEvent passEvent,
            RendererListDesc rendererListDesc)
            : this(
                passEvent,
                rendererListDesc,
                DrawingSettings.CreateDefault())
        {
        }

        public DrawObjectsPass(
            RenderPassEvent passEvent,
            RendererListDesc rendererListDesc,
            DrawingSettings drawingSettings)
        {
            Configure(
                passEvent,
                rendererListDesc,
                drawingSettings);
        }

        public void Configure(
            RenderPassEvent passEvent,
            RendererListDesc rendererListDesc)
        {
            Configure(
                passEvent,
                rendererListDesc,
                DrawingSettings.CreateDefault());
        }

        public void Configure(
            RenderPassEvent passEvent,
            RendererListDesc rendererListDesc,
            DrawingSettings drawingSettings)
        {
            renderPassEvent = passEvent;
            m_rendererListDesc = rendererListDesc;
            m_drawingSettings = drawingSettings;
        }

        public override void RecordRenderGraph(
            RenderGraph renderGraph,
            ContextContainer frameData)
        {
            if (renderGraph == null ||
                frameData == null)
            {
                return;
            }

            RenderingData renderingData =
                frameData.Get<RenderingData>();
            if (renderingData == null ||
                !renderingData.isSceneDrawStage)
            {
                return;
            }

            RendererListHandle rendererList =
                renderGraph.CreateRendererList(
                    m_rendererListDesc,
                    m_drawingSettings);
            if (!rendererList.isValid)
            {
                return;
            }

            RenderGraphTextureHandle primaryColorTarget =
                renderGraph.primaryColorTarget;
            RenderGraphTextureHandle depthTarget =
                renderGraph.depthTarget;
            if (!primaryColorTarget.isValid &&
                !depthTarget.isValid)
            {
                return;
            }

            RenderGraphRasterPassBuilder passBuilder =
                renderGraph.AddRasterPass(
                    ResolvePassName());
            if (primaryColorTarget.isValid)
            {
                passBuilder.SetColorAttachment(
                    primaryColorTarget);
            }

            if (depthTarget.isValid)
            {
                passBuilder.SetDepthAttachment(
                    depthTarget);
            }

            passBuilder
                .UseRendererList(rendererList)
                .SetRenderFunc(
                    rasterContext =>
                    {
                        rasterContext.cmd.DrawRendererList(
                            rendererList);
                    })
                .Commit();
        }

        protected override bool RecordRenderGraph(
            ScriptableRenderContext context,
            RenderingData renderingData)
        {
            return context != null &&
                   renderingData != null &&
                   renderingData.isSceneDrawStage &&
                   context.DrawRenderers(
                       m_rendererListDesc,
                       m_drawingSettings);
        }

        private string ResolvePassName()
        {
            switch (renderPassEvent)
            {
                case RenderPassEvent.BeforeRenderingShadows:
                case RenderPassEvent.AfterRenderingShadows:
                    return "Universal.DrawShadowCasterObjects";
                case RenderPassEvent.BeforeRenderingPrePasses:
                case RenderPassEvent.AfterRenderingPrePasses:
                    return "Universal.DrawDepthOnlyObjects";
                case RenderPassEvent.BeforeRenderingTransparents:
                case RenderPassEvent.RenderTransparents:
                case RenderPassEvent.AfterRenderingTransparents:
                    return "Universal.DrawTransparentObjects";
                case RenderPassEvent.BeforeRenderingOpaques:
                case RenderPassEvent.RenderOpaques:
                case RenderPassEvent.AfterRenderingOpaques:
                default:
                    return m_rendererListDesc.type ==
                           RendererListType.Transparent
                        ? "Universal.DrawTransparentObjects"
                        : "Universal.DrawOpaqueObjects";
            }
        }
    }
}