/*
  Copyright 2012-2020 David Robillard <d@drobilla.net>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

/**
   @file pugl.hpp
   @brief Pugl C++ API wrapper.
*/

#ifndef PUGL_PUGL_HPP
#define PUGL_PUGL_HPP

#include "pugl/pugl.h"

#include <cstdint>

#if defined(PUGL_HPP_THROW_FAILED_CONSTRUCTION)
#	include <exception>
#elif defined(PUGL_HPP_ASSERT_CONSTRUCTION)
#	include <cassert>
#endif

namespace pugl {

/**
   @defgroup puglxx Pugl C++ API
   C++ API wrapper.

   @ingroup pugldoc
   @{
*/

namespace detail {

/// Free function for a C object
template<typename T>
using FreeFunc = void (*)(T*);

/// Generic C++ wrapper for a C object
template<class T, FreeFunc<T> Free>
class Wrapper
{
public:
	Wrapper(const Wrapper&) = delete;
	Wrapper& operator=(const Wrapper&) = delete;

	Wrapper(Wrapper&& wrapper) noexcept
	    : _ptr{wrapper._ptr}
	{
		wrapper._ptr = nullptr;
	}

	Wrapper& operator=(Wrapper&& wrapper) noexcept
	{
		_ptr         = wrapper._ptr;
		wrapper._ptr = nullptr;
		return *this;
	}

	~Wrapper() noexcept { Free(_ptr); }

	T*       cobj() noexcept { return _ptr; }
	const T* cobj() const noexcept { return _ptr; }

protected:
	explicit Wrapper(T* ptr) noexcept
	    : _ptr{ptr}
	{}

private:
	T* _ptr;
};

} // namespace detail

using Rect = PuglRect; ///< @copydoc PuglRect

/**
   @name Events
   @{
*/

/**
   A strongly-typed analogue of PuglEvent.

   This is bit-for-bit identical to the corresponding PuglEvent, so events are
   simply cast to this type to avoid any copying overhead.

   @tparam t The `type` field of the corresponding PuglEvent.

   @tparam Base The specific struct type of the corresponding PuglEvent.
*/
template<PuglEventType t, class Base>
struct Event final : Base {
	using BaseEvent = Base;

	static constexpr const PuglEventType type = t;
};

using Mod          = PuglMod;          ///< @copydoc PuglMod
using Mods         = PuglMods;         ///< @copydoc PuglMods
using Key          = PuglKey;          ///< @copydoc PuglKey
using EventType    = PuglEventType;    ///< @copydoc PuglEventType
using EventFlag    = PuglEventFlag;    ///< @copydoc PuglEventFlag
using EventFlags   = PuglEventFlags;   ///< @copydoc PuglEventFlags
using CrossingMode = PuglCrossingMode; ///< @copydoc PuglCrossingMode

/// @copydoc PuglEventCreate
using CreateEvent = Event<PUGL_CREATE, PuglEventCreate>;

/// @copydoc PuglEventDestroy
using DestroyEvent = Event<PUGL_DESTROY, PuglEventDestroy>;

/// @copydoc PuglEventConfigure
using ConfigureEvent = Event<PUGL_CONFIGURE, PuglEventConfigure>;

/// @copydoc PuglEventMap
using MapEvent = Event<PUGL_MAP, PuglEventMap>;

/// @copydoc PuglEventUnmap
using UnmapEvent = Event<PUGL_UNMAP, PuglEventUnmap>;

/// @copydoc PuglEventUpdate
using UpdateEvent = Event<PUGL_UPDATE, PuglEventUpdate>;

/// @copydoc PuglEventExpose
using ExposeEvent = Event<PUGL_EXPOSE, PuglEventExpose>;

/// @copydoc PuglEventClose
using CloseEvent = Event<PUGL_CLOSE, PuglEventClose>;

/// @copydoc PuglEventFocus
using FocusInEvent = Event<PUGL_FOCUS_IN, PuglEventFocus>;

/// @copydoc PuglEventFocus
using FocusOutEvent = Event<PUGL_FOCUS_OUT, PuglEventFocus>;

/// @copydoc PuglEventKey
using KeyPressEvent = Event<PUGL_KEY_PRESS, PuglEventKey>;

/// @copydoc PuglEventKey
using KeyReleaseEvent = Event<PUGL_KEY_RELEASE, PuglEventKey>;

/// @copydoc PuglEventText
using TextEvent = Event<PUGL_TEXT, PuglEventText>;

/// @copydoc PuglEventCrossing
using PointerInEvent = Event<PUGL_POINTER_IN, PuglEventCrossing>;

/// @copydoc PuglEventCrossing
using PointerOutEvent = Event<PUGL_POINTER_OUT, PuglEventCrossing>;

/// @copydoc PuglEventButton
using ButtonPressEvent = Event<PUGL_BUTTON_PRESS, PuglEventButton>;

/// @copydoc PuglEventButton
using ButtonReleaseEvent = Event<PUGL_BUTTON_RELEASE, PuglEventButton>;

/// @copydoc PuglEventMotion
using MotionEvent = Event<PUGL_MOTION, PuglEventMotion>;

/// @copydoc PuglEventScroll
using ScrollEvent = Event<PUGL_SCROLL, PuglEventScroll>;

/// @copydoc PuglEventClient
using ClientEvent = Event<PUGL_CLIENT, PuglEventClient>;

/// @copydoc PuglEventTimer
using TimerEvent = Event<PUGL_TIMER, PuglEventTimer>;

/// @copydoc PuglEventLoopEnter
using LoopEnterEvent = Event<PUGL_LOOP_ENTER, PuglEventLoopEnter>;

/// @copydoc PuglEventLoopLeave
using LoopLeaveEvent = Event<PUGL_LOOP_LEAVE, PuglEventLoopLeave>;

/**
   @}
   @name Status
   @{
*/

/// @copydoc PuglStatus
enum class Status {
	success,             ///< @copydoc PUGL_SUCCESS
	failure,             ///< @copydoc PUGL_FAILURE
	unknownError,        ///< @copydoc PUGL_UNKNOWN_ERROR
	badBackend,          ///< @copydoc PUGL_BAD_BACKEND
	badConfiguration,    ///< @copydoc PUGL_BAD_CONFIGURATION
	badParameter,        ///< @copydoc PUGL_BAD_PARAMETER
	backendFailed,       ///< @copydoc PUGL_BACKEND_FAILED
	registrationFailed,  ///< @copydoc PUGL_REGISTRATION_FAILED
	realizeFailed,       ///< @copydoc PUGL_REALIZE_FAILED
	setFormatFailed,     ///< @copydoc PUGL_SET_FORMAT_FAILED
	createContextFailed, ///< @copydoc PUGL_CREATE_CONTEXT_FAILED
	unsupportedType,     ///< @copydoc PUGL_UNSUPPORTED_TYPE
};

static_assert(Status(PUGL_UNSUPPORTED_TYPE) == Status::unsupportedType, "");

/// @copydoc puglStrerror
inline const char*
strerror(const Status status) noexcept
{
	return puglStrerror(static_cast<PuglStatus>(status));
}

/**
   @}
   @name World
   @{
*/

/// @copydoc PuglWorldType
enum class WorldType {
	program, ///< @copydoc PUGL_PROGRAM
	module,  ///< @copydoc PUGL_MODULE
};

static_assert(WorldType(PUGL_MODULE) == WorldType::module, "");

/// @copydoc PuglWorldFlag
enum class WorldFlag {
	threads = PUGL_WORLD_THREADS, ///< @copydoc PUGL_WORLD_THREADS
};

static_assert(WorldFlag(PUGL_WORLD_THREADS) == WorldFlag::threads, "");

using WorldFlags = PuglWorldFlags; ///< @copydoc PuglWorldFlags

#if defined(PUGL_HPP_THROW_FAILED_CONSTRUCTION)

/// An exception thrown when construction fails
class FailedConstructionError : public std::exception
{
public:
	FailedConstructionError(const char* const msg) noexcept
	    : _msg{msg}
	{}

	virtual const char* what() const noexcept override;

private:
	const char* _msg;
};

#	define PUGL_CHECK_CONSTRUCTION(cond, msg)      \
		do {                                        \
			if (!(cond)) {                          \
				throw FailedConstructionError(msg); \
			}                                       \
		} while (0)

#elif defined(PUGL_HPP_ASSERT_CONSTRUCTION)
#	define PUGL_CHECK_CONSTRUCTION(cond, msg) assert(cond);
#else
#	define PUGL_CHECK_CONSTRUCTION(cond, msg)
#endif

/// @copydoc PuglWorld
class World : public detail::Wrapper<PuglWorld, puglFreeWorld>
{
public:
	World(const World&) = delete;
	World& operator=(const World&) = delete;

	World(World&&) = delete;
	World& operator=(World&&) = delete;

	~World() = default;

	World(WorldType type, WorldFlag flag)
	    : Wrapper{puglNewWorld(static_cast<PuglWorldType>(type),
	                           static_cast<PuglWorldFlags>(flag))}
	{
		PUGL_CHECK_CONSTRUCTION(cobj(), "Failed to create pugl::World");
	}

	World(WorldType type, WorldFlags flags)
	    : Wrapper{puglNewWorld(static_cast<PuglWorldType>(type), flags)}
	{
		PUGL_CHECK_CONSTRUCTION(cobj(), "Failed to create pugl::World");
	}

	explicit World(WorldType type)
	    : World{type, WorldFlags{}}
	{}

	/// @copydoc puglGetNativeWorld
	void* nativeWorld() noexcept { return puglGetNativeWorld(cobj()); }

	/// @copydoc puglSetClassName
	Status setClassName(const char* const name) noexcept
	{
		return static_cast<Status>(puglSetClassName(cobj(), name));
	}

	/// @copydoc puglGetTime
	double time() const noexcept { return puglGetTime(cobj()); }

	/// @copydoc puglUpdate
	Status update(const double timeout) noexcept
	{
		return static_cast<Status>(puglUpdate(cobj(), timeout));
	}
};

/**
   @}
   @name View
   @{
*/

using Backend    = PuglBackend;    ///< @copydoc PuglBackend
using NativeView = PuglNativeView; ///< @copydoc PuglNativeView

/// @copydoc PuglViewHint
enum class ViewHint {
	useCompatProfile,    ///< @copydoc PUGL_USE_COMPAT_PROFILE
	useDebugContext,     ///< @copydoc PUGL_USE_DEBUG_CONTEXT
	contextVersionMajor, ///< @copydoc PUGL_CONTEXT_VERSION_MAJOR
	contextVersionMinor, ///< @copydoc PUGL_CONTEXT_VERSION_MINOR
	redBits,             ///< @copydoc PUGL_RED_BITS
	greenBits,           ///< @copydoc PUGL_GREEN_BITS
	blueBits,            ///< @copydoc PUGL_BLUE_BITS
	alphaBits,           ///< @copydoc PUGL_ALPHA_BITS
	depthBits,           ///< @copydoc PUGL_DEPTH_BITS
	stencilBits,         ///< @copydoc PUGL_STENCIL_BITS
	samples,             ///< @copydoc PUGL_SAMPLES
	doubleBuffer,        ///< @copydoc PUGL_DOUBLE_BUFFER
	swapInterval,        ///< @copydoc PUGL_SWAP_INTERVAL
	resizable,           ///< @copydoc PUGL_RESIZABLE
	ignoreKeyRepeat,     ///< @copydoc PUGL_IGNORE_KEY_REPEAT
	refreshRate,         ///< @copydoc PUGL_REFRESH_RATE
};

static_assert(ViewHint(PUGL_REFRESH_RATE) == ViewHint::refreshRate, "");

using ViewHintValue = PuglViewHintValue; ///< @copydoc PuglViewHintValue

/// @copydoc PuglCursor
enum class Cursor {
	arrow,     ///< @copydoc PUGL_CURSOR_ARROW
	caret,     ///< @copydoc PUGL_CURSOR_CARET
	crosshair, ///< @copydoc PUGL_CURSOR_CROSSHAIR
	hand,      ///< @copydoc PUGL_CURSOR_HAND
	no,        ///< @copydoc PUGL_CURSOR_NO
	leftRight, ///< @copydoc PUGL_CURSOR_LEFT_RIGHT
	upDown,    ///< @copydoc PUGL_CURSOR_UP_DOWN
};

static_assert(Cursor(PUGL_CURSOR_UP_DOWN) == Cursor::upDown, "");

/// @copydoc PuglView
class View : protected detail::Wrapper<PuglView, puglFreeView>
{
public:
	/**
	   @name Setup
	   Methods for creating and destroying a view.
	   @{
	*/

	explicit View(World& world)
	    : Wrapper{puglNewView(world.cobj())}
	    , _world(world)
	{
		PUGL_CHECK_CONSTRUCTION(cobj(), "Failed to create pugl::View");
	}

	const World& world() const noexcept { return _world; }
	World&       world() noexcept { return _world; }

	/**
	   Set the object that will be called to handle events.

	   This is a type-safe wrapper for the C functions puglSetHandle() and
	   puglSetEventFunc() that will automatically dispatch events to the
	   `onEvent` method of `handler` that takes the appropriate event type.
	   The handler must have such a method defined for every event type, but if
	   the handler is the view itself, a `using` declaration can be used to
	   "inherit" the default implementation to avoid having to define every
	   method.  For example:

	   @code
	   class MyView : public pugl::View
	   {
	   public:
	       explicit MyView(pugl::World& world)
	           : pugl::View{world}
	       {
	           setEventHandler(*this);
	       }

	       using pugl::View::onEvent;

	       pugl::Status onEvent(const pugl::ConfigureEvent& event) noexcept;
	       pugl::Status onEvent(const pugl::ExposeEvent& event) noexcept;
	   };
	   @endcode

	   This facility is just a convenience, applications may use the C API
	   directly to set a handle and event function to set up a different
	   approach for event handling.
	*/
	template<class Handler>
	Status setEventHandler(Handler& handler)
	{
		puglSetHandle(cobj(), &handler);
		return static_cast<Status>(
		    puglSetEventFunc(cobj(), eventFunc<Handler>));
	}

	/// @copydoc puglSetBackend
	Status setBackend(const PuglBackend* backend) noexcept
	{
		return static_cast<Status>(puglSetBackend(cobj(), backend));
	}

	/// @copydoc puglSetViewHint
	Status setHint(ViewHint hint, int value) noexcept
	{
		return static_cast<Status>(
		    puglSetViewHint(cobj(), static_cast<PuglViewHint>(hint), value));
	}

	/// @copydoc puglGetViewHint
	int getHint(ViewHint hint) noexcept
	{
		return puglGetViewHint(cobj(), static_cast<PuglViewHint>(hint));
	}

	/**
	   @}
	   @name Frame
	   Methods for working with the position and size of a view.
	   @{
	*/

	/// @copydoc puglGetFrame
	Rect frame() const noexcept { return puglGetFrame(cobj()); }

	/// @copydoc puglSetFrame
	Status setFrame(Rect frame) noexcept
	{
		return static_cast<Status>(puglSetFrame(cobj(), frame));
	}

	/// @copydoc puglSetDefaultSize
	Status setDefaultSize(int width, int height) noexcept
	{
		return static_cast<Status>(puglSetDefaultSize(cobj(), width, height));
	}

	/// @copydoc puglSetMinSize
	Status setMinSize(int width, int height) noexcept
	{
		return static_cast<Status>(puglSetMinSize(cobj(), width, height));
	}

	/// @copydoc puglSetMaxSize
	Status setMaxSize(int width, int height) noexcept
	{
		return static_cast<Status>(puglSetMaxSize(cobj(), width, height));
	}

	/// @copydoc puglSetAspectRatio
	Status setAspectRatio(int minX, int minY, int maxX, int maxY) noexcept
	{
		return static_cast<Status>(
		    puglSetAspectRatio(cobj(), minX, minY, maxX, maxY));
	}

	/**
	   @}
	   @name Windows
	   Methods for working with top-level windows.
	   @{
	*/

	/// @copydoc puglSetWindowTitle
	Status setWindowTitle(const char* title) noexcept
	{
		return static_cast<Status>(puglSetWindowTitle(cobj(), title));
	}

	/// @copydoc puglSetParentWindow
	Status setParentWindow(NativeView parent) noexcept
	{
		return static_cast<Status>(puglSetParentWindow(cobj(), parent));
	}

	/// @copydoc puglSetTransientFor
	Status setTransientFor(NativeView parent) noexcept
	{
		return static_cast<Status>(puglSetTransientFor(cobj(), parent));
	}

	/// @copydoc puglRealize
	Status realize() noexcept
	{
		return static_cast<Status>(puglRealize(cobj()));
	}

	/// @copydoc puglShow
	Status show() noexcept
	{
		return static_cast<Status>(puglShow(cobj()));
	}

	/// @copydoc puglHide
	Status hide() noexcept
	{
		return static_cast<Status>(puglHide(cobj()));
	}

	/// @copydoc puglGetVisible
	bool visible() const noexcept { return puglGetVisible(cobj()); }

	/// @copydoc puglGetNativeWindow
	NativeView nativeWindow() noexcept { return puglGetNativeWindow(cobj()); }

	/**
	   @}
	   @name Graphics
	   Methods for working with the graphics context and scheduling
	   redisplays.
	   @{
	*/

	/// @copydoc puglGetContext
	void* context() noexcept { return puglGetContext(cobj()); }

	/// @copydoc puglPostRedisplay
	Status postRedisplay() noexcept
	{
		return static_cast<Status>(puglPostRedisplay(cobj()));
	}

	/// @copydoc puglPostRedisplayRect
	Status postRedisplayRect(const Rect rect) noexcept
	{
		return static_cast<Status>(puglPostRedisplayRect(cobj(), rect));
	}

	/**
	   @}
	   @name Interaction
	   Methods for interacting with the user and window system.
	   @{
	*/

	/// @copydoc puglGrabFocus
	Status grabFocus() noexcept
	{
		return static_cast<Status>(puglGrabFocus(cobj()));
	}

	/// @copydoc puglHasFocus
	bool hasFocus() const noexcept { return puglHasFocus(cobj()); }

	/// @copydoc puglSetCursor
	Status setCursor(const Cursor cursor) noexcept
	{
		return static_cast<Status>(
		    puglSetCursor(cobj(), static_cast<PuglCursor>(cursor)));
	}

	/// @copydoc puglRequestAttention
	Status requestAttention() noexcept
	{
		return static_cast<Status>(puglRequestAttention(cobj()));
	}

	/// @copydoc puglStartTimer
	Status startTimer(const uintptr_t id, const double timeout) noexcept
	{
		return static_cast<Status>(puglStartTimer(cobj(), id, timeout));
	}

	/// @copydoc puglStopTimer
	Status stopTimer(const uintptr_t id) noexcept
	{
		return static_cast<Status>(puglStopTimer(cobj(), id));
	}

	/**
	   @}
	*/

	PuglView*       cobj() noexcept { return Wrapper::cobj(); }
	const PuglView* cobj() const noexcept { return Wrapper::cobj(); }

private:
	template<class Target>
	static Status dispatch(Target& target, const PuglEvent* event)
	{
		switch (event->type) {
		case PUGL_NOTHING:
			return Status::success;
		case PUGL_CREATE:
			return target.onEvent(static_cast<const CreateEvent&>(event->any));
		case PUGL_DESTROY:
			return target.onEvent(static_cast<const DestroyEvent&>(event->any));
		case PUGL_CONFIGURE:
			return target.onEvent(
			    static_cast<const ConfigureEvent&>(event->configure));
		case PUGL_MAP:
			return target.onEvent(static_cast<const MapEvent&>(event->any));
		case PUGL_UNMAP:
			return target.onEvent(static_cast<const UnmapEvent&>(event->any));
		case PUGL_UPDATE:
			return target.onEvent(static_cast<const UpdateEvent&>(event->any));
		case PUGL_EXPOSE:
			return target.onEvent(
			    static_cast<const ExposeEvent&>(event->expose));
		case PUGL_CLOSE:
			return target.onEvent(static_cast<const CloseEvent&>(event->any));
		case PUGL_FOCUS_IN:
			return target.onEvent(
			    static_cast<const FocusInEvent&>(event->focus));
		case PUGL_FOCUS_OUT:
			return target.onEvent(
			    static_cast<const FocusOutEvent&>(event->focus));
		case PUGL_KEY_PRESS:
			return target.onEvent(
			    static_cast<const KeyPressEvent&>(event->key));
		case PUGL_KEY_RELEASE:
			return target.onEvent(
			    static_cast<const KeyReleaseEvent&>(event->key));
		case PUGL_TEXT:
			return target.onEvent(static_cast<const TextEvent&>(event->text));
		case PUGL_POINTER_IN:
			return target.onEvent(
			    static_cast<const PointerInEvent&>(event->crossing));
		case PUGL_POINTER_OUT:
			return target.onEvent(
			    static_cast<const PointerOutEvent&>(event->crossing));
		case PUGL_BUTTON_PRESS:
			return target.onEvent(
			    static_cast<const ButtonPressEvent&>(event->button));
		case PUGL_BUTTON_RELEASE:
			return target.onEvent(
			    static_cast<const ButtonReleaseEvent&>(event->button));
		case PUGL_MOTION:
			return target.onEvent(
			    static_cast<const MotionEvent&>(event->motion));
		case PUGL_SCROLL:
			return target.onEvent(
			    static_cast<const ScrollEvent&>(event->scroll));
		case PUGL_CLIENT:
			return target.onEvent(
			    static_cast<const ClientEvent&>(event->client));
		case PUGL_TIMER:
			return target.onEvent(static_cast<const TimerEvent&>(event->timer));
		case PUGL_LOOP_ENTER:
			return target.onEvent(
			    static_cast<const LoopEnterEvent&>(event->any));
		case PUGL_LOOP_LEAVE:
			return target.onEvent(
			    static_cast<const LoopLeaveEvent&>(event->any));
		}

		return Status::failure;
	}

	template<class Target>
	static PuglStatus eventFunc(PuglView* view, const PuglEvent* event) noexcept
	{
		auto* target = static_cast<Target*>(puglGetHandle(view));

#ifdef __cpp_exceptions
		try {
			return static_cast<PuglStatus>(dispatch(*target, event));
		} catch (...) {
			return PUGL_UNKNOWN_ERROR;
		}
#else
		return static_cast<PuglStatus>(pugl::dispatch(*target, event));
#endif
	}

	World& _world;
};

/**
   @}
   @}
*/

} // namespace pugl

#endif // PUGL_PUGL_HPP