//
// Created by erki on 12/09/23.
//

#pragma once

#include <memory>
#include <array>
#include <cstring>

#include <utility_function.hpp>
#include <utility_ringbuffer.hpp>

#include "cpptick/argstore.hpp"
#include "cpptick/scheduler.hpp"

namespace cpptick
{

template<typename>
struct Slot;

template<typename R, SlotArgument... Args>
struct Slot<R(Args...)>
{
  std::array<Utility::IFunction<R (Args...)>*, 12> signals;
  Scheduler* scheduler;

  Utility::FunctionOwned<Slot<R(Args...)>, void (ArgStorage&)> invoke_ptr;

  Slot() = delete;
  explicit Slot(Scheduler* sched)
      : scheduler(sched)
      , invoke_ptr(*this, &Slot<R(Args...)>::callUp)
  {
    signals.fill(nullptr);
  }

  Slot(const Slot&) = delete;
  Slot(Slot&&) = delete;
  Slot& operator=(const Slot&) = delete;
  Slot& operator=(Slot&&) = delete;

  void connect(Utility::IFunction<R (Args...)>* signal)
  {
    for (auto*& callable : signals)
    {
      if (callable == nullptr)
      {
        callable = signal;
        break;
      }
    }
  }

  Utility::IFunction<R (Args...)>* connect(R (*func)(Args...))
  {
    auto* f = new Utility::Function<R (Args...)>(func);

    connect(f);

    return f;
  }

  template<typename Source>
  Utility::IFunction<R (Args...)>* connect(Source& src, R (Source::* func)(Args...))
  {
    auto* f = new Utility::FunctionOwned<Source, R (Args...)>(src, func);

    connect(f);

    return f;
  }

  template<size_t... Is>
  void callUpFunction(Utility::IFunction<R (Args...)>* func, ArgStorage& args, std::index_sequence<Is...>)
  {
    (*func)(std::forward<Args>(args.at<Args>(Is))...);
  }

  void callUpFunction(Utility::IFunction<R (Args...)>* func, ArgStorage& args)
  {
    callUpFunction(func, args, std::make_index_sequence<sizeof...(Args)>{});
  }

  void callUp(ArgStorage& args)
  {
    for (auto* f : signals)
    {
      if (f)
        callUpFunction(f, args);
      else
        break;
    }

    args.cleanUp<Args...>();
  }

  void invoke(Args... args)
  {
    ArgStorage& storage = scheduler->storeCall(&invoke_ptr);
    (storage.pushArg(std::forward<Args>(args)), ...);
  }
};

}