void Server::pleasePlay()

in csrc/HanabiServer.cc [476:539]
51 lines of code
11 McCabe index (conditional complexity)

void Server::pleasePlay(int index)
{
    assert(0 <= activePlayer_ && activePlayer_ < hands_.size());
    assert(players_.size() == hands_.size());
    HANABI_SERVER_ASSERT(movesFromActivePlayer_ < 1, "bot attempted to move twice");
    HANABI_SERVER_ASSERT(movesFromActivePlayer_ == 0, "called pleasePlay() from the wrong observer");
    HANABI_SERVER_ASSERT(0 <= index && index <= hands_[activePlayer_].size(), "invalid card index");

    Card selectedCard = hands_[activePlayer_][index];
    activeCard_ = selectedCard;
    activeCardIsObservable_ = true;

    /* Notify all the players of the attempted play (before it happens). */
    movesFromActivePlayer_ = -1;
    int oldObservingPlayer = observingPlayer_;
    for (int i=0; i < players_.size(); ++i) {
        observingPlayer_ = i;
        players_[i]->pleaseObserveBeforePlay(*this, activePlayer_, index);
    }
    observingPlayer_ = oldObservingPlayer;
    activeCardIsObservable_ = false;

    /* Examine the selected card. */
    Pile &pile = piles_[(int)selectedCard.color];

    if (pile.nextValueIs(selectedCard.value)) {
        if (log_) {
            (*log_) << "Player " << activePlayer_
                    << " played his " << nth(index, hands_[activePlayer_].size())
                    << " card (" << selectedCard.toString() << ").\n";
        }
        pile.increment_();
        if (selectedCard.value == 5) {
            /* Successfully playing a 5 regains a hint stone. */
            regainHintStoneIfPossible_();
        }
    } else {
        /* The card was unplayable! */
        if (log_) {
            (*log_) << "Player " << activePlayer_
                    << " tried to play his " << nth(index, hands_[activePlayer_].size())
                    << " card (" << selectedCard.toString() << ")"
                    << " but failed.\n";
        }
        discards_.push_back(selectedCard);
        loseMulligan_();
    }

    /* Shift the old cards down, and draw a replacement if possible. */
    hands_[activePlayer_].erase(hands_[activePlayer_].begin() + index);

    if (mulligansRemaining_ > 0 && !deck_.empty()) {
        Card replacementCard = this->draw_();
        hands_[activePlayer_].push_back(replacementCard);
        if (log_) {
            (*log_) << "Player " << activePlayer_
                    << " drew a replacement (" << replacementCard.toString() << ").\n";
        }
    }

    this->logPiles_();

    movesFromActivePlayer_ = 1;
}