/*
This Source Code Form is subject to the
terms of the Mozilla Public License, v.
2.0. If a copy of the MPL was not
distributed with this file, You can
obtain one at
http://mozilla.org/MPL/2.0/.
*/

#ifndef PYINT_H
#define PYINT_H

#ifdef _POSIX_C_SOURCE
#undef _POSIX_C_SOURCE
#endif

#ifdef _XOPEN_SOURCE
#undef _XOPEN_SOURCE
#endif

#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 5033)
#endif
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wregister"
#endif

#ifdef WITH_PYTHON
#ifdef _DEBUG
#undef _DEBUG // bez tego macra Py_DECREF powoduja problemy przy linkowaniu
#include "Python.h"
#define _DEBUG
#else
#include "Python.h"
#endif
#else
#define PyObject void
#define PyThreadState void
#endif

#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif
#ifdef _MSC_VER
#pragma warning(pop)
#endif

#include "Classes.h"
#include "utilities.h"
#include "Texture.h"
#include <thread>

#define PyGetFloat(param) PyFloat_FromDouble(param)
#define PyGetInt(param) PyInt_FromLong(param)
#define PyGetBool(param) param ? Py_True : Py_False
#define PyGetString(param) PyString_FromString(param)

// python rendertarget
struct python_rt
{
	std::mutex mutex;

	ITexture *shared_tex;

	int format;
	int components;
	int width;
	int height;
	std::string image;

	std::chrono::high_resolution_clock::time_point timestamp;
};

// TODO: extract common base and inherit specialization from it
class render_task
{

  public:
	// constructors
	render_task(PyObject *Renderer, std::shared_ptr<dictionary_source> Input, std::shared_ptr<python_rt> Target) : m_renderer(Renderer), m_input(Input), m_target(Target) {}
	// methods
	void run();
	void upload();
	void cancel();
	auto target() const -> std::shared_ptr<python_rt>
	{
		return m_target;
	}

  private:
	// members
	PyObject *m_renderer{nullptr};
	std::shared_ptr<dictionary_source> m_input{nullptr};
	std::shared_ptr<python_rt> m_target{nullptr};
};

class python_taskqueue
{

  public:
	// types
	struct task_request
	{

		std::string const &renderer;
		std::shared_ptr<dictionary_source> input;
		std::shared_ptr<python_rt> target;
	};
	// constructors
	python_taskqueue() = default;
	// methods
	// initializes the module. returns true on success
	auto init() -> bool;
	// shuts down the module
	void exit();
	// adds specified task along with provided collection of data to the work queue. returns true on success
	auto insert(task_request const &Task) -> bool;
	// executes python script stored in specified file. returns true on success
	auto run_file(std::string const &File, std::string const &Path = "") -> bool;
	// acquires the python gil and sets the main thread as current
	void acquire_lock();
	// releases the python gil and swaps the main thread out
	void release_lock();

	void update();

  private:
	// types
	static int const WORKERCOUNT{1};
	using worker_array = std::array<std::jthread, WORKERCOUNT>;
	using rendertask_sequence = threading::lockable<std::deque<std::shared_ptr<render_task>>>;
	using uploadtask_sequence = threading::lockable<std::deque<std::shared_ptr<render_task>>>;
	// methods
	auto fetch_renderer(std::string const Renderer) -> PyObject *;
	void run(GLFWwindow *Context, rendertask_sequence &Tasks, uploadtask_sequence &Upload_Tasks, threading::condition_variable &Condition, std::atomic<bool> &Exit);
	void error();

	// members
	PyObject *m_main{nullptr};
	PyObject *m_stderr{nullptr};
	PyThreadState *m_mainthread{nullptr};
	worker_array m_workers;
	threading::condition_variable m_condition; // wakes up the workers
	std::atomic<bool> m_exit{false}; // signals the workers to quit
	std::unordered_map<std::string, PyObject *> m_renderers; // cache of python classes
	rendertask_sequence m_tasks;
	uploadtask_sequence m_uploadtasks;
	bool m_initialized{false};
};

class python_external_utils
{
  public:
	static std::vector<std::string> PyObjectToStringArray(PyObject *pyList);
};

#endif