Endgame-Analyzer/download.h

#ifndef DYNAMIC_PROGRAM_DOWNLOAD_H
#define DYNAMIC_PROGRAM_DOWNLOAD_H

#include <boost/json.hpp>
#include <boost/json/src.hpp>
#include <cpr/cpr.h>
#include <iostream>
#include <fstream>
#include <variant>

#include "game_state.h"


// This helper function deduces the type and assigns the value with the matching key
template<class T>
void extract( boost::json::object const& obj, T& t, std::string_view key )
{
  t = value_to<T>( obj.at( key ) );
}

namespace Hanabi {
  Card tag_invoke(boost::json::value_to_tag<Card>,
                          boost::json::value const &jv) {
    Hanabi::Card card{};
    boost::json::object const &obj = jv.as_object();
    extract(obj, card.rank, "rank");
    extract(obj, card.suit, "suitIndex");
    card.rank = 5 - card.rank;
    return card;
  }

  void tag_invoke(boost::json::value_from_tag, boost::json::value &jv, Hanabi::Card const &card) {
    jv = {{"suitIndex", card.suit}, {"rank", card.rank}};
  }
}


std::vector<Hanabi::Card> parse_deck(const boost::json::value& deck_json) {
    auto deck = boost::json::value_to<std::vector<Hanabi::Card>>(deck_json);
    std::array<std::array<Hanabi::rank_t, 5>, 6> next_copy_indices {};
    for(size_t i = 0; i < deck.size(); i++) {
      auto &card = deck[i];
      assert(card.rank < 5);
      assert(card.rank >= 0);
      assert(card.suit < 6);
      assert(card.suit >= 0);
      card.index = i;
      card.copy = next_copy_indices[card.suit][card.rank];
      next_copy_indices[card.suit][card.rank]++;
    }
    return deck;
}

boost::json::object download_game_json(int game_id) {
  std::string request_str = "https://hanab.live/export/" + std::to_string(game_id);
  cpr::Response r = cpr::Get(cpr::Url(request_str));
  if (r.header["content-type"] != "application/json; charset=utf-8") {
    return {};
  }
  return boost::json::parse(r.text).as_object();
}

boost::json::object open_game_json(const char* filename) {
  std::ifstream file(filename);
  if (!file.is_open()) {
    std::cout << "Failed to open " << filename << "." << std::endl;
    return {};
  }
  std::string game_json ((std::istreambuf_iterator<char>(file)), std::istreambuf_iterator<char>());
  return boost::json::parse(game_json).as_object();
}

void get_game(std::variant<int, const char*> game_spec) {
  const boost::json::object game = [&game_spec](){
    if (game_spec.index() == 0) {
      return download_game_json(std::get<int>(game_spec));
    } else {
      return open_game_json(std::get<const char*>(game_spec));
    }
  }();
  const std::vector<Hanabi::Card> deck = parse_deck(game.at("deck"));
  const unsigned num_players = game.at("players").as_array().size();
  std::cout << deck.size() << std::endl;
  std::cout << num_players;
}




#endif // DYNAMIC_PROGRAM_DOWNLOAD_H