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"
#include "myassert.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}};
    }
}

namespace Download {

    struct Action {
        Hanabi::ActionType type{};
        uint8_t target;
    };

    Action tag_invoke(boost::json::value_to_tag<Action>, boost::json::value const &jv) {
        Action action{};
        uint8_t type;
        boost::json::object const &obj = jv.as_object();

        extract(obj, action.target, "target");
        extract(obj, type, "type");

        action.type = static_cast<Hanabi::ActionType>(type);
        switch (action.type) {
            case Hanabi::ActionType::color_clue:
            case Hanabi::ActionType::rank_clue:
                action.type = Hanabi::ActionType::clue;
                break;
            case Hanabi::ActionType::end_game:
            case Hanabi::ActionType::vote_terminate:
                action.type = Hanabi::ActionType::end_game;
                break;
            case Hanabi::ActionType::play:
            case Hanabi::ActionType::discard:
                break;
            default:
                throw std::runtime_error(
                        "Invalid game format, could not parse action type " + std::to_string(type));
        }
        return action;
    }

    std::vector<Hanabi::Card> parse_deck(const boost::json::value &deck_json) {
        auto deck = boost::json::value_to<std::vector<Hanabi::Card>>(deck_json);
        for (auto &card: deck) {
            ASSERT(card.rank < 5);
            ASSERT(card.rank >= 0);
            ASSERT(card.suit < 6);
            ASSERT(card.suit >= 0);
        }
        return deck;
    }

    std::vector<Action> parse_actions(const boost::json::value &action_json) {
        return boost::json::value_to<std::vector<Action>>(action_json);
    }

    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();
    }

    template<std::size_t num_suits, Hanabi::player_t num_players, std::size_t hand_size>
    Hanabi::HanabiState<num_suits, num_players, hand_size> produce_state(
            const std::vector<Hanabi::Card>& deck,
            const std::vector<Action>& actions,
            size_t num_turns_to_replicate
    ) {
      Hanabi::HanabiState<num_suits, num_players, hand_size> game(deck);
      std::uint8_t index;
      for (size_t i = 0; i < num_turns_to_replicate; i++) {
          switch(actions[i].type) {
              case Hanabi::ActionType::color_clue:
              case Hanabi::ActionType::rank_clue:
                  game.clue();
                  break;
              case Hanabi::ActionType::discard:
                  index = game.find_card_in_hand(deck[actions[i].target]);
                  ASSERT(index != -1);
                  game.discard(index);
                  break;
              case Hanabi::ActionType::play:
                  index = game.find_card_in_hand(deck[actions[i].target]);
                  ASSERT(index != -1);
                  game.play(index);
                  break;
              case Hanabi::ActionType::vote_terminate:
              case Hanabi::ActionType::end_game:
                  return game;
          }
      }
      return game;
    }

    template <std::size_t num_suits, Hanabi::player_t num_players, std::size_t hand_size>
    Hanabi::HanabiState<num_suits, num_players, hand_size> get_game(std::variant<int, const char *> game_spec, unsigned turn) {
        const boost::json::object game_json = [&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_json.at("deck"));
        const std::vector<Action> actions = parse_actions(game_json.at("actions"));
        const size_t num_players_js = game_json.at("players").as_array().size();
        ASSERT (num_players_js == num_players);

        auto game = produce_state<num_suits, num_players, hand_size>(deck, actions, turn);
        game.normalize_draw_and_positions();
        return game;
    }


} // namespacen Download

#endif // DYNAMIC_PROGRAM_DOWNLOAD_H