#include <iostream>
#include <utility>
#include <sstream>
#include <string>
#include <array>
#include <stdexcept>
#include <functional>
#include "solutions.hpp"

using namespace std; 

typedef std::pair<std::string, std::string>(*solution_t)(std::istream&);
template <unsigned long N> void init_solutions(std::array<solution_t, N> &solutions);

template <unsigned int N>
pair<string, string> solve(istream&) {
    stringstream s;
    s << "solution " << N << " not implemented";
    throw logic_error(s.str());
}

template <unsigned long I>
constexpr void do_init(solution_t *solutions) {
    solutions[I-1] = solve<I>;
    do_init<I-1>(solutions);
}

template <>
constexpr void do_init<1>(solution_t *solutions) {
    solutions[0] = solve<1>;
}

template <unsigned long N>
void init_solutions(array<solution_t, N> &solutions) {
    do_init<N>(solutions.data());
}

int main(int argc, char *argv[]) {
    array<pair<string,string>(*)(istream&), 25> solutions;
    init_solutions(solutions);
    if (argc < 2) {
        return 0;
    }
    int problem_number = stoi(string(argv[1]));
    try {
    auto x = solutions.at(problem_number-1);
    auto answer = x(cin);
    cout << "Solution 1: " << answer.first << endl;
    cout << "Solution 2: " << answer.second << endl;
    } catch (exception const &e) {
        cerr << "error: " << e.what() << endl;
    }
    return 0;
}


//istream get_input() {
//    CURL *curl;
//    CURLcode res;
//
//    char url[44] = {0};
//    sprintf(url, "https://adventofcode.com/2020/day/%d/input");
//
//    curl_global_init(CURL_GLOBAL_ALL);
//    curl = curl_easy_init();
//    curl_easy_setopt(curl, CURLOPT_URL, "https://adventofcode.com/2020/day/1/input");
//    curl_easy_setopt(curl, CURLOPT_URL, "https://adventofcode.com/2020/day/1/input");
//
//    curl_global_cleanup();
//}
// TODO: automatically download input files and stuff
//    char *home_dir = getenv("HOME");
//    if (home_dir != NULL) {
//
//    }