// This file is part of the 64k demo project.
// It implements the ShaderComposer class.

#include "gpu/effects/shader_composer.h"
#include <sstream>

ShaderComposer& ShaderComposer::Get() {
  static ShaderComposer instance;
  return instance;
}

void ShaderComposer::RegisterSnippet(const std::string& name,
                                     const std::string& code) {
  snippets_[name] = code;
}

std::string
ShaderComposer::Compose(const std::vector<std::string>& dependencies,
                        const std::string& main_code) {
  std::stringstream ss;
  ss << "// Generated by ShaderComposer\n\n";

  for (const auto& dep : dependencies) {
    auto it = snippets_.find(dep);
    if (it != snippets_.end()) {
      ss << "// --- Snippet: " << dep << " ---\n";
      ss << it->second << "\n";
    }
  }

  ss << "// --- Main Code ---\n";
  ss << main_code;

  return ss.str();
}