// This file is part of the 64k demo project.
// It implements SDF-related pipeline logic for Renderer3D.

#include "3d/renderer.h"
#include "generated/assets.h"
#include "gpu/effects/shader_composer.h"
#include "util/asset_manager.h"
#include <vector>

void Renderer3D::create_pipeline() {
  pipeline_ = create_pipeline_impl(true);         // BVH enabled
  pipeline_no_bvh_ = create_pipeline_impl(false); // BVH disabled
  create_mesh_pipeline();
}

WGPURenderPipeline Renderer3D::create_pipeline_impl(bool use_bvh) {
  std::vector<WGPUBindGroupLayoutEntry> entries;

  // Binding 0: Global Uniforms
  {
    WGPUBindGroupLayoutEntry e = {};
    e.binding = 0;
    e.visibility = WGPUShaderStage_Vertex | WGPUShaderStage_Fragment;
    e.buffer.type = WGPUBufferBindingType_Uniform;
    e.buffer.minBindingSize = sizeof(GlobalUniforms);
    entries.push_back(e);
  }

  // Binding 1: Object Data
  {
    WGPUBindGroupLayoutEntry e = {};
    e.binding = 1;
    e.visibility = WGPUShaderStage_Vertex | WGPUShaderStage_Fragment;
    e.buffer.type = WGPUBufferBindingType_ReadOnlyStorage;
    e.buffer.minBindingSize = sizeof(ObjectData) * kMaxObjects;
    entries.push_back(e);
  }

  // Binding 2: BVH Nodes (only if BVH is used)
  if (use_bvh) {
    WGPUBindGroupLayoutEntry e = {};
    e.binding = 2;
    e.visibility = WGPUShaderStage_Fragment;
    e.buffer.type = WGPUBufferBindingType_ReadOnlyStorage;
    e.buffer.minBindingSize = sizeof(BVHNode) * kMaxObjects * 2;
    entries.push_back(e);
  }

  // Binding 3: Noise Texture
  {
    WGPUBindGroupLayoutEntry e = {};
    e.binding = 3;
    e.visibility = WGPUShaderStage_Fragment;
    e.texture.sampleType = WGPUTextureSampleType_Float;
    e.texture.viewDimension = WGPUTextureViewDimension_2D;
    entries.push_back(e);
  }

  // Binding 4: Default Sampler
  {
    WGPUBindGroupLayoutEntry e = {};
    e.binding = 4;
    e.visibility = WGPUShaderStage_Fragment;
    e.sampler.type = WGPUSamplerBindingType_Filtering;
    entries.push_back(e);
  }

  // Binding 5: Sky Texture
  {
    WGPUBindGroupLayoutEntry e = {};
    e.binding = 5;
    e.visibility = WGPUShaderStage_Fragment;
    e.texture.sampleType = WGPUTextureSampleType_Float;
    e.texture.viewDimension = WGPUTextureViewDimension_2D;
    entries.push_back(e);
  }

  WGPUBindGroupLayoutDescriptor bgl_desc = {};
  bgl_desc.entryCount = (uint32_t)entries.size();
  bgl_desc.entries = entries.data();
  WGPUBindGroupLayout bgl = wgpuDeviceCreateBindGroupLayout(device_, &bgl_desc);

  WGPUPipelineLayoutDescriptor pl_desc = {};
  pl_desc.bindGroupLayoutCount = 1;
  pl_desc.bindGroupLayouts = &bgl;
  WGPUPipelineLayout pipeline_layout =
      wgpuDeviceCreatePipelineLayout(device_, &pl_desc);

  const char* asset_data =
      (const char*)GetAsset(AssetId::ASSET_SHADER_RENDERER_3D);
  std::string main_code = asset_data;

  // Use ShaderComposer to dynamically include the correct scene_query snippet
  ShaderComposer::CompositionMap composition_map;
  if (use_bvh) {
    composition_map["render/scene_query_mode"] = "render/scene_query_bvh";
  } else {
    composition_map["render/scene_query_mode"] = "render/scene_query_linear";
  }
  std::string shader_source =
      ShaderComposer::Get().Compose({}, main_code, composition_map);

#if defined(DEMO_CROSS_COMPILE_WIN32)
  WGPUShaderModuleWGSLDescriptor wgsl_desc = {};
  wgsl_desc.chain.sType = WGPUSType_ShaderModuleWGSLDescriptor;
  wgsl_desc.code = shader_source.c_str();
  WGPUShaderModuleDescriptor shader_desc = {};
  shader_desc.nextInChain = (const WGPUChainedStruct*)&wgsl_desc.chain;
#else
  WGPUShaderSourceWGSL wgsl_desc = {};
  wgsl_desc.chain.sType = WGPUSType_ShaderSourceWGSL;
  wgsl_desc.code = str_view(shader_source.c_str());
  WGPUShaderModuleDescriptor shader_desc = {};
  shader_desc.nextInChain = (const WGPUChainedStruct*)&wgsl_desc.chain;
#endif
  WGPUShaderModule shader_module =
      wgpuDeviceCreateShaderModule(device_, &shader_desc);

  WGPUDepthStencilState depth_stencil = {};
  depth_stencil.format = WGPUTextureFormat_Depth24Plus;
  depth_stencil.depthWriteEnabled = WGPUOptionalBool_True;
  depth_stencil.depthCompare = WGPUCompareFunction_Less;

  WGPURenderPipelineDescriptor desc = {};
  desc.layout = pipeline_layout;
  desc.vertex.module = shader_module;
#if defined(DEMO_CROSS_COMPILE_WIN32)
  desc.vertex.entryPoint = "vs_main";
#else
  desc.vertex.entryPoint = {"vs_main", 7};
#endif
  WGPUColorTargetState color_target = {};
  color_target.format = format_;
  color_target.writeMask = WGPUColorWriteMask_All;
  WGPUFragmentState fragment = {};
  fragment.module = shader_module;
#if defined(DEMO_CROSS_COMPILE_WIN32)
  fragment.entryPoint = "fs_main";
#else
  fragment.entryPoint = {"fs_main", 7};
#endif
  fragment.targetCount = 1;
  fragment.targets = &color_target;
  desc.fragment = &fragment;
  desc.primitive.topology = WGPUPrimitiveTopology_TriangleList;
  desc.primitive.cullMode = WGPUCullMode_Back;
  desc.primitive.frontFace = WGPUFrontFace_CCW;
  desc.depthStencil = &depth_stencil;
  desc.multisample.count = 1;
  desc.multisample.mask = 0xFFFFFFFF;

  WGPURenderPipeline pipeline = wgpuDeviceCreateRenderPipeline(device_, &desc);
  wgpuBindGroupLayoutRelease(bgl);
  wgpuPipelineLayoutRelease(pipeline_layout);
  wgpuShaderModuleRelease(shader_module);

  return pipeline;
}