#include <span>
#include <vector>
#include <fstream>
#include <expected>
#include <system_error>
#include <ranges>

#include "fmt/format.h"

#include "aoc/aoc.hpp"

namespace vfp {
using namespace aoc::types;
using page_order_rule = std::vector<i32>;

class manual_updates {};
}

auto entry([[maybe_unused]]std::span<char const*> const& args) -> std::expected<void, aoc::error> {
    using namespace std::string_view_literals;
    auto txtres = aoc::read_text("./dat/24/ex/05.txt");
    if (!txtres) return std::unexpected(txtres.error());
    auto const txt = *txtres;

    auto const not_empty = [](auto const& str) { return !str.empty(); };
    auto lines = txt | std::views::split("\n"sv)
                     | std::views::transform([](auto const& str) { return std::string_view(str); });

    auto rules   = lines | std::views::take_while(not_empty)
                         | std::ranges::to<std::vector>();
    auto updates = lines | std::views::drop_while(not_empty) | std::views::drop(1)
                         | std::ranges::to<std::vector>();


    fmt::print("rules:\n");
    std::ranges::for_each(rules,  [](auto const& str) {
        fmt::print("{}\n", str);
    });

    fmt::print("updates:\n");
    std::ranges::for_each(updates,  [](auto const& str) {
        fmt::print("{}\n", str);
    });

    return {};
}

auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
    auto const res = entry({argv, static_cast<std::size_t>(argc)});
    if (res) return 0;
    fmt::print(stderr, "{}: {}\n", res.error().err.message(), res.error().msg);
    return 1;
}