MetaTicTacToe/ttt_engine.cpp

//
// Created by nositelshtanov on 11/11/2023.
//

#include "ttt_engine.h"

ttt_engine::ttt_engine() : map{
        mark::nothing, mark::nothing, mark::nothing,
        mark::nothing, mark::nothing, mark::nothing,
        mark::nothing, mark::nothing, mark::nothing
    },
    winner(mark::nothing),
    step_count(0),
    win_combinations{
           0, 1, 2,
           3, 4, 5,
           6, 7, 8,
           0, 3, 6,
           1, 4, 7,
           2, 5, 8,
           2, 4, 6,
           0, 4, 8
    } {}

void ttt_engine::step(mark whose_step, std::size_t field_num) {
    if (winner != mark::nothing || is_game_end()) { throw step_error{"game is end", step_error::Reason::game_already_end}; }
    if (map[field_num] != mark::nothing) { throw step_error{step_error::Reason::the_field_is_occupied}; }
    if (field_num > 8) { throw invalid_coords_error(); }

    map[field_num] = whose_step;
    ++step_count;

    winner = who_is_winner();
    if (winner != mark::nothing) { whose_step = mark::nothing; }
}

mark ttt_engine::who_is_winner() const {
    for (combination comb : win_combinations) {
        if (is_same_marks(map[comb[0]], map[comb[1]], map[comb[2]]) && map[comb[0]] != mark::nothing) {
            return map[comb[0]];
        }
    }

    return mark::nothing;
}