// Gaussian blur effect implementation

#include "effects/gaussian_blur_effect.h"
#include "effects/shaders.h"
#include "gpu/post_process_helper.h"
#include "util/fatal_error.h"

GaussianBlur::GaussianBlur(const GpuContext& ctx,
                           const std::vector<std::string>& inputs,
                           const std::vector<std::string>& outputs, float start_time,
                           float end_time)
    : Effect(ctx, inputs, outputs, start_time, end_time), pipeline_(nullptr), bind_group_(nullptr) {
  HEADLESS_RETURN_IF_NULL(ctx_.device);

  init_uniforms_buffer();
  create_linear_sampler();
  params_buffer_.init(ctx_.device);

  pipeline_ = create_post_process_pipeline(
      ctx_.device, WGPUTextureFormat_RGBA8Unorm, gaussian_blur_shader_wgsl);
}

void GaussianBlur::render(WGPUCommandEncoder encoder,
                          const UniformsSequenceParams& params,
                          NodeRegistry& nodes) {
  // Get input/output views
  WGPUTextureView input_view = nodes.get_view(input_nodes_[0]);
  WGPUTextureView output_view = nodes.get_view(output_nodes_[0]);

  // Update uniforms
  uniforms_buffer_.update(ctx_.queue, params);
  params_buffer_.update(ctx_.queue, blur_params_);

  // Update bind group
  WGPUBindGroupEntry entries[4] = {};
  entries[0].binding = PP_BINDING_SAMPLER;
  entries[0].sampler = sampler_.get();
  entries[1].binding = PP_BINDING_TEXTURE;
  entries[1].textureView = input_view;
  entries[2].binding = PP_BINDING_UNIFORMS;
  entries[2].buffer = uniforms_buffer_.get().buffer;
  entries[2].size = sizeof(UniformsSequenceParams);
  entries[3].binding = PP_BINDING_EFFECT_PARAMS;
  entries[3].buffer = params_buffer_.get().buffer;
  entries[3].size = sizeof(GaussianBlurParams);

  WGPUBindGroupDescriptor bg_desc = {};
  bg_desc.layout = wgpuRenderPipelineGetBindGroupLayout(pipeline_, 0);
  bg_desc.entryCount = 4;
  bg_desc.entries = entries;

  if (bind_group_) {
    wgpuBindGroupRelease(bind_group_);
  }
  bind_group_ = wgpuDeviceCreateBindGroup(ctx_.device, &bg_desc);

  // Render pass
  WGPURenderPassColorAttachment color_attachment = {};
  gpu_init_color_attachment(color_attachment, output_view);

  WGPURenderPassDescriptor pass_desc = {};
  pass_desc.colorAttachmentCount = 1;
  pass_desc.colorAttachments = &color_attachment;

  WGPURenderPassEncoder pass =
      wgpuCommandEncoderBeginRenderPass(encoder, &pass_desc);
  wgpuRenderPassEncoderSetPipeline(pass, pipeline_);
  wgpuRenderPassEncoderSetBindGroup(pass, 0, bind_group_, 0, nullptr);
  wgpuRenderPassEncoderDraw(pass, 3, 1, 0, 0);
  wgpuRenderPassEncoderEnd(pass);
  wgpuRenderPassEncoderRelease(pass);
}