#include "BowlingScore.h"

BowlingScore::BowlingScore()
{}

void BowlingScore::ParseInput(const std::string& p_input)
{
    std::copy(p_input.begin(), p_input.end(), std::back_inserter(sequence));
}

unsigned BowlingScore::Calculate()
{
    for(auto iterator = sequence.begin(); iterator != sequence.end(); ++iterator)
    {
        score.push_back(GetSymbolValue(iterator));
    }
    auto score_iterator = score.begin();
    int weak_symbol_counter = 0, steps = 0, sum = 0;
    auto nextStep = [&](){
        ++steps;
        weak_symbol_counter = 0;
    };

    for(auto symbol_iterator = sequence.begin(); symbol_iterator != sequence.end() && steps != 10; ++score_iterator, ++symbol_iterator)
    {
        if(*symbol_iterator == 'X')
        {
            Strike(score_iterator);
            nextStep();
        }
        else if(*symbol_iterator == '/')
        {
            Spare(score_iterator);
            nextStep();
        }
        else if(weak_symbol_counter == 1)
        {
            nextStep();
        }
        else
        {
            ++weak_symbol_counter;
        }
        sum += *score_iterator;
    }

    return sum;
}

unsigned BowlingScore::GetSymbolValue(std::vector<char>::iterator iterator) {
    if(*iterator == '-')
        return 0;
    else if(*iterator == '/')
        return 10 - GetSymbolValue(std::prev(iterator));
    else if(*iterator == 'X')
        return 10;
    else
        return (unsigned)(*iterator - '0');
}

void BowlingScore::Spare(std::vector<int>::iterator score_iterator)
{
    *score_iterator += *std::next(score_iterator);
}

void BowlingScore::Strike(std::vector<int>::iterator score_iterator)
{
    *score_iterator += *std::next(score_iterator);
    *score_iterator += *std::next(score_iterator, 2);
}