// WgslEffect: generic shader-only post-process effect.

#include "gpu/wgsl_effect.h"
#include "gpu/gpu.h"
#include "gpu/post_process_helper.h"
#include "util/fatal_error.h"

WgslEffect::WgslEffect(const GpuContext& ctx,
                       const std::vector<std::string>& inputs,
                       const std::vector<std::string>& outputs,
                       float start_time, float end_time,
                       const char* shader_code, WGPULoadOp load_op,
                       WgslEffectParams initial_params)
    : Effect(ctx, inputs, outputs, start_time, end_time),
      effect_params(initial_params),
      load_op_(load_op) {
  HEADLESS_RETURN_IF_NULL(ctx_.device);

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

  pipeline_.set(create_post_process_pipeline(ctx_.device,
                                             WGPUTextureFormat_RGBA8Unorm,
                                             shader_code));
}

void WgslEffect::render(WGPUCommandEncoder encoder,
                        const UniformsSequenceParams& params,
                        NodeRegistry& nodes) {
  WGPUTextureView input_view = nodes.get_view(input_nodes_[0]);
  WGPUTextureView output_view = nodes.get_view(output_nodes_[0]);

  params_buffer_.update(ctx_.queue, effect_params);

  pp_update_bind_group(ctx_.device, pipeline_.get(), bind_group_.get_address(),
                       input_view, uniforms_buffer_.get(),
                       params_buffer_.get());

  WGPURenderPassColorAttachment color_attachment = {};
  gpu_init_color_attachment(color_attachment, output_view);
  color_attachment.loadOp = load_op_;

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

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