#include <fstream>
#include <iostream>
#include <sstream>
#include <vector>

enum Command {
    Forward,
    Down,
    Up,
    Undefined,
};
using CommandPair = std::pair<Command, int>;

std::vector<CommandPair> getCommands(const std::string &file_name) {
    std::ifstream file(file_name);
    std::vector<CommandPair> result{};
    std::string tmp_command{};
    int tmp_num{};
    std::string str;
    while (std::getline(file, str)) {
        std::stringstream ss(str);
        ss >> tmp_command;
        ss >> tmp_num;
        Command cmd = Undefined;
        if (tmp_command == "forward") {
            cmd = Forward;
        } else if (tmp_command == "down") {
            cmd = Down;
        } else if (tmp_command == "up") {
            cmd = Up;
        }
        if (cmd == Undefined) {
            std::cerr << "Invalid input line: \"" << str << "\"" << std::endl;
            return {};
        }
        result.emplace_back(cmd, tmp_num);
    }
    return result;
}

int part1(const std::vector<CommandPair> &commands) {
    int x = 0;
    int y = 0;
    for (const auto &command : commands) {
        switch (command.first) {
        case Forward:
            x += command.second;
            break;
        case Down:
            y += command.second;
            break;
        case Up:
            y -= command.second;
        default:
            break;
        }
    }
    return x * y;
}

int part2(const std::vector<CommandPair> &commands) {
    int x = 0;
    int y = 0;
    int aim = 0;
    for (const auto &command : commands) {
        switch (command.first) {
        case Forward:
            x += command.second;
            y += aim * command.second;
            break;
        case Down:
            aim += command.second;
            break;
        case Up:
            aim -= command.second;
        default:
            break;
        }
    }
    return x * y;
}

int main(int argc, char **argv) {
    if (argc < 2) {
        std::cerr << "You must provide input file!" << std::endl;
        return 1;
    }
    auto commands = getCommands(argv[1]);
    if (commands.empty()) {
        return 1;
    }
    std::cout << "The resulting multiplication is \033[91;1m" << part1(commands)
              << "\033[0m." << std::endl;
    std::cout << "The correct resulting multiplication is \033[91;1m"
              << part2(commands) << "\033[0m." << std::endl;
    return 0;
}