#include <fstream>
#include <iostream>
#include <vector>

#include "yaml-cpp/eventhandler.h"
#include "yaml-cpp/yaml.h" // IWYU pragma: keep

struct Params {
 bool hasFile;
 std::string fileName;
};

Params ParseArgs(int argc, char** argv) {
 Params p;

 std::vector<std::string> args(argv + 1, argv + argc);

 return p;
}

class NullEventHandler : public YAML::EventHandler {
 public:
 void OnDocumentStart(const YAML::Mark&) override {}
 void OnDocumentEnd() override {}

 void OnNull(const YAML::Mark&, YAML::anchor_t) override {}
 void OnAlias(const YAML::Mark&, YAML::anchor_t) override {}
 void OnScalar(const YAML::Mark&, const std::string&, YAML::anchor_t,
 const std::string&) override {}

 void OnSequenceStart(const YAML::Mark&, const std::string&, YAML::anchor_t,
 YAML::EmitterStyle::value) override {}
 void OnSequenceEnd() override {}

 void OnMapStart(const YAML::Mark&, const std::string&, YAML::anchor_t,
 YAML::EmitterStyle::value) override {}
 void OnMapEnd() override {}
};

void parse(std::istream& input) {
 try {
 YAML::Node doc = YAML::Load(input);
 std::cout << doc << "\n";
 } catch (const YAML::Exception& e) {
 std::cerr << e.what() << "\n";
 }
}

int main(int argc, char** argv) {
 Params p = ParseArgs(argc, argv);

 if (argc > 1) {
 std::ifstream fin;
 fin.open(argv[1]);
 parse(fin);
 } else {
 parse(std::cin);
 }

 return 0;
}