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#pragma once

#include "cancel.h"
#include "deep.h"
#include "universe.h"

#include <array>
#include <condition_variable>
#include <string_view>
#include <variant>

struct Keeper;

// #################################################################################################

// xxh64 of string "kLindaBatched" generated at https://www.pelock.com/products/hash-calculator
static constexpr UniqueKey kLindaBatched{ 0xB8234DF772646567ull, "linda.batched" };

// #################################################################################################

using LindaGroup = Unique<int>;

class Linda
: public DeepPrelude // Deep userdata MUST start with this header
{
    private:
    static constexpr size_t kEmbeddedNameLength = 24;
    using EmbeddedName = std::array<char, kEmbeddedNameLength>;
    // depending on the name length, it is either embedded inside the Linda, or allocated separately
    std::variant<std::string_view, EmbeddedName> nameVariant;

    public:
    std::condition_variable readHappened;
    std::condition_variable writeHappened;
    Universe* const U{ nullptr }; // the universe this linda belongs to
    int const keeperIndex{ -1 }; // the keeper associated to this linda
    CancelRequest cancelRequest{ CancelRequest::None };

    public:
    [[nodiscard]] static void* operator new(size_t size_, Universe* U_) noexcept { return U_->internalAllocator.alloc(size_); }
    // always embedded somewhere else or "in-place constructed" as a full userdata
    // can't actually delete the operator because the compiler generates stack unwinding code that could call it in case of exception
    static void operator delete(void* p_, Universe* U_) { U_->internalAllocator.free(p_, sizeof(Linda)); }
    // this one is for us, to make sure memory is freed by the correct allocator
    static void operator delete(void* p_) { static_cast<Linda*>(p_)->U->internalAllocator.free(p_, sizeof(Linda)); }

    ~Linda();
    Linda(Universe* U_, LindaGroup group_, std::string_view const& name_);
    Linda() = delete;
    // non-copyable, non-movable
    Linda(Linda const&) = delete;
    Linda(Linda const&&) = delete;
    Linda& operator=(Linda const&) = delete;
    Linda& operator=(Linda const&&) = delete;

    private:
    void freeAllocatedName();
    void setName(std::string_view const& name_);

    public:
    [[nodiscard]] Keeper* acquireKeeper() const;
    [[nodiscard]] std::string_view getName() const;
    void releaseKeeper(Keeper* keeper_) const;
    [[nodiscard]] static int ProtectedCall(lua_State* L_, lua_CFunction f_);
    [[nodiscard]] Keeper* whichKeeper() const { return U->keepers.getKeeper(keeperIndex); }
};