#pragma once

#include "coding/file_reader.hpp"

#include "base/geo_object_id.hpp"
#include "base/logging.hpp"

#include <string>
#include <unordered_set>

#include "3party/jansson/myjansson.hpp"

namespace promo
{
using Cities = std::unordered_set<base::GeoObjectId>;

inline Cities LoadCities(std::string const & filename)
{
  if (filename.empty())
    return {};

  std::string src;
  FileReader reader(filename);
  reader.ReadAsString(src);

  Cities result;
  base::Json root(src.c_str());
  auto const dataArray = json_object_get(root.get(), "data");

  auto const size = json_array_size(dataArray);

  result.reserve(size);
  for (size_t i = 0; i < size; ++i)
  {
    int64_t id = 0;
    auto const obj = json_array_get(dataArray, i);
    FromJSONObject(obj, "osmid", id);

    result.emplace(static_cast<uint64_t>(id));
  }

  return result;
}
}  // namespace promo