#pragma once
#include "compat/int-hash.hpp"
#include "global-coords.hpp"
#include "tile.hpp"
#include <unordered_map>
#include <memory>
#include <optional>

namespace floormat {

struct chunk;

struct world final
{
    world();
    std::shared_ptr<chunk> operator[](chunk_coords c) noexcept;
    std::tuple<std::shared_ptr<chunk>, tile&> operator[](global_coords pt) noexcept;
    bool contains(chunk_coords c) const noexcept;
    void clear();
    void collect();

private:
    void maybe_collect();

    static constexpr std::size_t initial_capacity = 64, collect_every = 32;
    static constexpr float max_load_factor = .5;
    static constexpr auto hasher = [](chunk_coords c) -> std::size_t {
        return int_hash((std::size_t)c.y << 16 | (std::size_t)c.x);
    };

    std::size_t _last_collection = 0;
    mutable std::optional<std::tuple<std::shared_ptr<chunk>, chunk_coords>> _last_chunk;
    std::unordered_map<chunk_coords, std::shared_ptr<chunk>, decltype(hasher)> _chunks{initial_capacity, hasher};
};

} // namespace floormat