#include <span>
#include <algorithm>
#include <ranges>
#include <string>
#include <string_view>
#include <utility>
#include <vector>
#include <tuple>

#include "fmt/std.h"

#include "aoc/types.hpp"
#include "aoc/utils.hpp"

using namespace std::string_view_literals;
using namespace aoc::types;

// starts at 50
[[maybe_unused]]constexpr auto raw_str = R"(
.......S.......
...............
.......^.......
...............
......^.^......
...............
.....^.^.^.....
...............
....^.^...^....
...............
...^.^...^.^...
...............
..^...^.....^..
...............
.^.^.^.^.^...^.
...............
)";

static auto entry([[maybe_unused]]std::span<char const*> const& args) -> void {
    // std::string str{raw_str};
    auto str = aoc::read_text("./input.txt").value_or("");
    str = aoc::trim(str);

    auto mat = str | std::views::split("\n"sv) | std::views::transform([](auto line) {
                    return line | std::views::split(""sv)
                                | std::views::transform([](auto tok) {
                                        return std::string{std::begin(tok), std::end(tok)};
                                    })
                                | std::ranges::to<std::vector>();
      }) | std::ranges::to<std::vector>();

    struct beam {
        usize row;
        usize col;
    };

    std::vector<beam> beams{};
    for (usize i = 0; i < mat.size(); ++i) {
        for (usize j = 0; j < mat[i].size(); ++j) {
            if (mat[i][j] == "S") {
                beams.push_back({i, j});
                break;
            }

            auto const size = beams.size();
            for (usize k = 0; k < size; ++k) {
                if (beams[k].row == i - 1 && beams[k].col == j) {
                    if (mat[i][j] == ".") {
                        mat[i][j] = "|";
                        beams[k] = {i, j};
                    } else if (mat[i][j] == "^") {
                        beams[k] = {i, j - 1};
                        beams.push_back({i, j + 1});
                        mat[i][j - 1] = "|";
                        mat[i][j + 1] = "|";
                    }
                }
            }
        }
    }

    f64 sum = 0.0;
    for (usize i = 0; i < mat.size(); ++i) {
        for (usize j = 0; j < mat[i].size(); ++j) {
            if (mat[i][j] == "^") {
                if (mat[i - 1][j] == "|") sum += 1;
            }
        }
    }

    fmt::print("res: {}\n", sum);

    // for (auto const& row : mat) {
    //     for (auto const& col : row) {
    //         fmt::print("{}", col);
    //     }
    //     fmt::print("\n");
    // }
}

auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
    try {
        entry({argv, std::next(argv, argc)});
    } catch (std::exception const& e) {
        fmt::print(stderr, "{}\n", e.what());
        return 1;
    }
    return 0;
}