#include "macro-action-scene-visibility.hpp"
#include "layout-helpers.hpp"
#include "macro-helpers.hpp"
#include "plugin-state-helpers.hpp"
#include "sync-helpers.hpp"
#include "transition-helpers.hpp"

#include <obs-frontend-api.h>

namespace advss {

const std::string MacroActionSceneVisibility::id = "scene_visibility";

bool MacroActionSceneVisibility::_registered = MacroActionFactory::Register(
	MacroActionSceneVisibility::id,
	{MacroActionSceneVisibility::Create,
	 MacroActionSceneVisibilityEdit::Create,
	 "AdvSceneSwitcher.action.sceneVisibility"});

const static std::map<MacroActionSceneVisibility::Action, std::string>
	actionTypes = {
		{MacroActionSceneVisibility::Action::SHOW,
		 "AdvSceneSwitcher.action.sceneVisibility.type.show"},
		{MacroActionSceneVisibility::Action::HIDE,
		 "AdvSceneSwitcher.action.sceneVisibility.type.hide"},
		{MacroActionSceneVisibility::Action::TOGGLE,
		 "AdvSceneSwitcher.action.sceneVisibility.type.toggle"},
};

namespace {

struct TransitionRestoreContext;
static std::unordered_map<obs_sceneitem_t *, TransitionRestoreContext *>
	restoreContexts;
static std::mutex restoreMutex;

struct TransitionRestoreContext {
public:
	obs_sceneitem_t *item;
	bool wasVisible;

	OBSSource originalTransition = nullptr;
	uint32_t originalDuration;

	obs_source_t *transition = nullptr;
	signal_handler_t *sh = nullptr;
};

} // namespace

static void handleShutdown(enum obs_frontend_event event, void *)
{
	if (event != OBS_FRONTEND_EVENT_EXIT) {
		return;
	}

	std::lock_guard<std::mutex> lock(restoreMutex);
	for (const auto &[_, ctx] : restoreContexts) {
		obs_source_release(ctx->transition);
	}
	restoreContexts.clear();
}

static bool setup()
{
	obs_frontend_add_event_callback(handleShutdown, nullptr);
	return true;
}

static bool setupDone = setup();

static void handleSourceDestroyed(void *param, calldata_t *)
{
	if (OBSIsShuttingDown()) {
		return;
	}

	auto ctx = static_cast<TransitionRestoreContext *>(param);
	ctx->sh = nullptr;
	ctx->originalTransition = nullptr;
	delete ctx;
}

static void resetSceneItemTransition(void *param, calldata_t *)
{
	if (OBSIsShuttingDown()) {
		return;
	}

	auto ctx = static_cast<TransitionRestoreContext *>(param);

	if (!ctx) {
		return;
	}

	SetSceneItemTransition(ctx->item, ctx->originalTransition,
			       !ctx->wasVisible);

	obs_sceneitem_set_transition_duration(ctx->item, !ctx->wasVisible,
					      ctx->originalDuration);

	signal_handler_disconnect(ctx->sh, "transition_stop",
				  resetSceneItemTransition, ctx);
	signal_handler_disconnect(ctx->sh, "destroy", handleSourceDestroyed,
				  ctx);

	{
		std::lock_guard<std::mutex> lock(restoreMutex);
		restoreContexts.erase(ctx->item);
	}

	obs_source_release(ctx->transition);
	delete ctx;
}

static void attachRestoreContext(obs_sceneitem_t *item,
				 obs_source_t *transition, bool itemWasVisible,
				 OBSSource originalTransition,
				 uint32_t originalDuration)
{
	signal_handler_t *sh = obs_source_get_signal_handler(transition);
	if (!sh) {
		return;
	}

	std::lock_guard<std::mutex> lock(restoreMutex);

	auto ctx = new TransitionRestoreContext{
		item,
		itemWasVisible,
		originalTransition,
		originalDuration,
		obs_source_get_ref(transition),
		sh,
	};

	auto it = restoreContexts.find(item);
	if (it != restoreContexts.end()) {
		auto *oldCtx = it->second;

		signal_handler_disconnect(oldCtx->sh, "transition_stop",
					  resetSceneItemTransition, oldCtx);

		signal_handler_disconnect(oldCtx->sh, "destroy",
					  handleSourceDestroyed, oldCtx);

		ctx->originalTransition = oldCtx->originalTransition;
		ctx->originalDuration = oldCtx->originalDuration;

		obs_source_release(oldCtx->transition);
		delete oldCtx;

		restoreContexts.erase(it);
	}

	restoreContexts[item] = ctx;

	signal_handler_connect(sh, "transition_stop", resetSceneItemTransition,
			       ctx);
	signal_handler_connect(sh, "destroy", handleSourceDestroyed, ctx);
}

static obs_source_t *
setSceneItemVisibility(obs_sceneitem_t *item, const bool setTransition,
		       const OBSWeakSource &transitionWeak,
		       const bool setDuration, const Duration &duration,
		       MacroActionSceneVisibility::Action action)
{
	const OBSSourceAutoRelease transition = OBSGetStrongRef(transitionWeak);
	const bool itemIsVisible = obs_sceneitem_visible(item);

	const OBSSource currentTransition =
		obs_sceneitem_get_transition(item, !itemIsVisible);
	const uint32_t currentTransitionDuration =
		obs_sceneitem_get_transition_duration(item, !itemIsVisible);

	OBSSource privateTransitionSource = nullptr;
	if (setTransition) {
		privateTransitionSource = SetSceneItemTransition(
			item, transition, !itemIsVisible);
	} else {
		privateTransitionSource =
			obs_sceneitem_get_transition(item, !itemIsVisible);
	}

	if (setDuration) {
		obs_sceneitem_set_transition_duration(item, !itemIsVisible,
						      duration.Milliseconds());
	}

	switch (action) {
	case MacroActionSceneVisibility::Action::SHOW:
		obs_sceneitem_set_visible(item, true);
		break;
	case MacroActionSceneVisibility::Action::HIDE:
		obs_sceneitem_set_visible(item, false);
		break;
	case MacroActionSceneVisibility::Action::TOGGLE:
		obs_sceneitem_set_visible(item, !itemIsVisible);
		break;
	}

	if (!setTransition && !setDuration) {
		return privateTransitionSource;
	}

	if (!privateTransitionSource) {
		if (setTransition) {
			SetSceneItemTransition(item, currentTransition,
					       !itemIsVisible);
		}
		if (setDuration) {
			obs_sceneitem_set_transition_duration(
				item, !itemIsVisible,
				currentTransitionDuration);
		}
		return nullptr;
	}

	auto sh = obs_source_get_signal_handler(privateTransitionSource);
	if (!sh) {
		return nullptr;
	}

	attachRestoreContext(item, privateTransitionSource, itemIsVisible,
			     currentTransition, currentTransitionDuration);

	return privateTransitionSource;
}

namespace {

struct TransitionWaitItem {
	obs_sceneitem_t *sceneItem;
	obs_source_t *expectedSource;
	bool show;
	std::atomic<int> *pendingCount;
	std::atomic<bool> done{false};

	void markDone()
	{
		bool expected = false;
		if (done.compare_exchange_strong(expected, true)) {
			(*pendingCount)--;
			GetMacroTransitionCV().notify_all();
		}
	}
};

} // namespace

static void onTransitionDone(void *data, calldata_t *)
{
	static_cast<TransitionWaitItem *>(data)->markDone();
}

static void waitForSceneItemTransitions(
	std::atomic<int> &pendingCount,
	const std::vector<std::unique_ptr<TransitionWaitItem>> &waitItems,
	Macro *macro)
{
	using namespace std::chrono_literals;
	SetMacroAbortWait(false);
	std::unique_lock<std::mutex> lock(*GetMutex());
	while (pendingCount > 0 && !MacroWaitShouldAbort() &&
	       !MacroIsStopped(macro) && !OBSIsShuttingDown()) {
		GetMacroTransitionCV().wait_for(lock, 100ms);
		// Detect transitions replaced mid-wait (e.g. user sets
		// transition to "None" via OBS context menu). In that
		// case transition_stop never fires, so we poll.
		for (const auto &wi : waitItems) {
			if (wi->done) {
				continue;
			}
			obs_source_t *current = obs_sceneitem_get_transition(
				wi->sceneItem, wi->show);
			if (current != wi->expectedSource) {
				wi->markDone();
			}
		}
	}
}

bool MacroActionSceneVisibility::PerformAction()
{
	auto items = _source.GetSceneItems(_scene);

	if (!_blockUntilTransitionDone) {
		for (const auto &item : items) {
			setSceneItemVisibility(item, _updateTransition,
					       _transition.GetTransition(),
					       _updateDuration, _duration,
					       _action);
		}
		return true;
	}

	std::atomic<int> pendingCount(0);
	std::vector<OBSSourceAutoRelease> transitionSources;
	std::vector<std::unique_ptr<TransitionWaitItem>> waitItems;
	std::vector<OBSSignal> signalConnections;

	for (const auto &item : items) {
		const bool itemWasVisible = obs_sceneitem_visible(item);

		bool targetVisible;
		switch (_action) {
		case Action::SHOW:
			targetVisible = true;
			break;
		case Action::HIDE:
			targetVisible = false;
			break;
		case Action::TOGGLE:
			targetVisible = !itemWasVisible;
			break;
		default:
			continue;
		}

		if (itemWasVisible == targetVisible) {
			// No-op: visibility won't change, no transition will play
			setSceneItemVisibility(item, _updateTransition,
					       _transition.GetTransition(),
					       _updateDuration, _duration,
					       _action);
			continue;
		}

		auto *source = setSceneItemVisibility(
			item, _updateTransition, _transition.GetTransition(),
			_updateDuration, _duration, _action);
		if (!source) {
			continue;
		}

		auto *sh = obs_source_get_signal_handler(source);
		if (!sh) {
			continue;
		}

		transitionSources.emplace_back(obs_source_get_ref(source));
		++pendingCount;

		auto wi = std::make_unique<TransitionWaitItem>();
		wi->sceneItem = item;
		wi->expectedSource = source;
		wi->show = !itemWasVisible;
		wi->pendingCount = &pendingCount;

		signalConnections.emplace_back(sh, "transition_stop",
					       onTransitionDone, wi.get());
		waitItems.push_back(std::move(wi));
	}

	if (pendingCount == 0) {
		return true;
	}

	waitForSceneItemTransitions(pendingCount, waitItems, GetMacro());
	return !MacroWaitShouldAbort();
}

void MacroActionSceneVisibility::LogAction() const
{
	auto it = actionTypes.find(_action);
	if (it != actionTypes.end()) {
		ablog(LOG_INFO,
		      "performed visibility action \"%s\" for source \"%s\" on scene \"%s\"",
		      it->second.c_str(), _source.ToString(true).c_str(),
		      _scene.ToString(true).c_str());

	} else {
		blog(LOG_WARNING, "ignored unknown SceneVisibility action %d",
		     static_cast<int>(_action));
	}
}

bool MacroActionSceneVisibility::Save(obs_data_t *obj) const
{
	MacroAction::Save(obj);
	_scene.Save(obj);
	_source.Save(obj);
	obs_data_set_bool(obj, "updateTransition", _updateTransition);
	_transition.Save(obj);
	obs_data_set_bool(obj, "updateDuration", _updateDuration);
	_duration.Save(obj);
	obs_data_set_int(obj, "action", static_cast<int>(_action));
	obs_data_set_bool(obj, "blockUntilTransitionDone",
			  _blockUntilTransitionDone);
	return true;
}

bool MacroActionSceneVisibility::Load(obs_data_t *obj)
{
	// Convert old data format
	// TODO: Remove in future version
	if (obs_data_has_user_value(obj, "source")) {
		auto sourceName = obs_data_get_string(obj, "source");
		obs_data_set_string(obj, "sceneItem", sourceName);
	}

	MacroAction::Load(obj);
	_scene.Load(obj);
	_source.Load(obj);
	_updateTransition = obs_data_get_bool(obj, "updateTransition");
	_transition.Load(obj);
	_updateDuration = obs_data_get_bool(obj, "updateDuration");
	_duration.Load(obj);
	_action = static_cast<MacroActionSceneVisibility::Action>(
		obs_data_get_int(obj, "action"));
	_blockUntilTransitionDone =
		obs_data_get_bool(obj, "blockUntilTransitionDone");

	// TODO: Remove in future version
	if (obs_data_get_int(obj, "sourceType") != 0) {
		auto sourceGroup = obs_data_get_string(obj, "sourceGroup");
		_source.SetSourceTypeSelection(sourceGroup);
	}
	return true;
}

std::string MacroActionSceneVisibility::GetShortDesc() const
{
	if (!_source.ToString().empty()) {
		return _scene.ToString() + " - " + _source.ToString();
	}
	return "";
}

std::shared_ptr<MacroAction> MacroActionSceneVisibility::Create(Macro *m)
{
	return std::make_shared<MacroActionSceneVisibility>(m);
}

std::shared_ptr<MacroAction> MacroActionSceneVisibility::Copy() const
{
	return std::make_shared<MacroActionSceneVisibility>(*this);
}

void MacroActionSceneVisibility::ResolveVariablesToFixedValues()
{
	_scene.ResolveVariables();
	_source.ResolveVariables();
}

static inline void populateActionSelection(QComboBox *list)
{
	for (const auto &entry : actionTypes) {
		list->addItem(obs_module_text(entry.second.c_str()));
	}
}

MacroActionSceneVisibilityEdit::MacroActionSceneVisibilityEdit(
	QWidget *parent, std::shared_ptr<MacroActionSceneVisibility> entryData)
	: QWidget(parent),
	  _scenes(new SceneSelectionWidget(this, true, false, true, true)),
	  _sources(new SceneItemSelectionWidget(
		  parent,
		  {
			  SceneItemSelection::Type::SOURCE_NAME,
			  SceneItemSelection::Type::VARIABLE_NAME,
			  SceneItemSelection::Type::SOURCE_NAME_PATTERN,
			  SceneItemSelection::Type::SOURCE_GROUP,
			  SceneItemSelection::Type::SOURCE_TYPE,
			  SceneItemSelection::Type::INDEX,
			  SceneItemSelection::Type::INDEX_RANGE,
			  SceneItemSelection::Type::ALL,
		  },
		  SceneItemSelectionWidget::NameClashMode::ALL)),
	  _updateTransition(new QCheckBox(this)),
	  _transitions(new TransitionSelectionWidget(this, false, false)),
	  _updateDuration(new QCheckBox(this)),
	  _duration(new DurationSelection(this, false)),
	  _durationLayout(new QHBoxLayout),
	  _blockUntilTransitionDone(new QCheckBox(
		  obs_module_text(
			  "AdvSceneSwitcher.action.sceneVisibility.blockUntilTransitionDone"),
		  this)),
	  _actions(new QComboBox())
{
	populateActionSelection(_actions);

	_duration->SpinBox()->setSpecialValueText("-");

	QWidget::connect(_actions, SIGNAL(currentIndexChanged(int)), this,
			 SLOT(ActionChanged(int)));
	QWidget::connect(_scenes, SIGNAL(SceneChanged(const SceneSelection &)),
			 this, SLOT(SceneChanged(const SceneSelection &)));
	QWidget::connect(_scenes, SIGNAL(SceneChanged(const SceneSelection &)),
			 _sources, SLOT(SceneChanged(const SceneSelection &)));
	QWidget::connect(_sources,
			 SIGNAL(SceneItemChanged(const SceneItemSelection &)),
			 this, SLOT(SourceChanged(const SceneItemSelection &)));
	QWidget::connect(_updateTransition, SIGNAL(stateChanged(int)), this,
			 SLOT(UpdateTransitionChanged(int)));
	QWidget::connect(_transitions,
			 SIGNAL(TransitionChanged(const TransitionSelection &)),
			 this,
			 SLOT(TransitionChanged(const TransitionSelection &)));
	QWidget::connect(_updateDuration, SIGNAL(stateChanged(int)), this,
			 SLOT(UpdateDurationChanged(int)));
	QWidget::connect(_duration, SIGNAL(DurationChanged(const Duration &)),
			 this, SLOT(DurationChanged(const Duration &)));
	QWidget::connect(_blockUntilTransitionDone, SIGNAL(stateChanged(int)),
			 this, SLOT(BlockUntilTransitionDoneChanged(int)));

	auto sceneItemLayout = new QHBoxLayout;
	PlaceWidgets(obs_module_text(
			     "AdvSceneSwitcher.action.sceneVisibility.layout"),
		     sceneItemLayout,
		     {{"{{scenes}}", _scenes},
		      {"{{sources}}", _sources},
		      {"{{actions}}", _actions}});

	auto transitionLayout = new QHBoxLayout;
	PlaceWidgets(
		obs_module_text(
			"AdvSceneSwitcher.action.sceneVisibility.layout.transition"),
		transitionLayout,
		{{"{{updateTransition}}", _updateTransition},
		 {"{{transitions}}", _transitions}});

	PlaceWidgets(
		obs_module_text(
			"AdvSceneSwitcher.action.sceneVisibility.layout.duration"),
		_durationLayout,
		{{"{{updateDuration}}", _updateDuration},
		 {"{{duration}}", _duration}});

	auto layout = new QVBoxLayout;
	layout->addLayout(sceneItemLayout);
	layout->addLayout(transitionLayout);
	layout->addLayout(_durationLayout);
	layout->addWidget(_blockUntilTransitionDone);
	setLayout(layout);

	_entryData = entryData;
	UpdateEntryData();
	SetWidgetVisibility();
	_loading = false;
}

void MacroActionSceneVisibilityEdit::UpdateEntryData()
{
	if (!_entryData) {
		return;
	}

	_actions->setCurrentIndex(static_cast<int>(_entryData->_action));
	_scenes->SetScene(_entryData->_scene);
	_sources->SetSceneItem(_entryData->_source);
	_updateTransition->setChecked(_entryData->_updateTransition);
	_transitions->SetTransition(_entryData->_transition);
	_updateDuration->setChecked(_entryData->_updateDuration);
	_duration->SetDuration(_entryData->_duration);
	_blockUntilTransitionDone->setChecked(
		_entryData->_blockUntilTransitionDone);
}

void MacroActionSceneVisibilityEdit::SceneChanged(const SceneSelection &s)
{
	GUARD_LOADING_AND_LOCK();
	_entryData->_scene = s;
}

void MacroActionSceneVisibilityEdit::SourceChanged(
	const SceneItemSelection &item)
{
	GUARD_LOADING_AND_LOCK();
	_entryData->_source = item;
	emit HeaderInfoChanged(
		QString::fromStdString(_entryData->GetShortDesc()));
	adjustSize();
	updateGeometry();
}

void MacroActionSceneVisibilityEdit::UpdateTransitionChanged(int state)
{
	GUARD_LOADING_AND_LOCK();
	_entryData->_updateTransition = state;
	SetWidgetVisibility();
}

void MacroActionSceneVisibilityEdit::TransitionChanged(
	const TransitionSelection &t)
{
	GUARD_LOADING_AND_LOCK();
	_entryData->_transition = t;
	SetWidgetVisibility();
}

void MacroActionSceneVisibilityEdit::UpdateDurationChanged(int state)
{
	GUARD_LOADING_AND_LOCK();
	_entryData->_updateDuration = state;
	SetWidgetVisibility();
}

void MacroActionSceneVisibilityEdit::DurationChanged(const Duration &dur)
{
	GUARD_LOADING_AND_LOCK();
	_entryData->_duration = dur;
}

void MacroActionSceneVisibilityEdit::ActionChanged(int value)
{
	GUARD_LOADING_AND_LOCK();
	_entryData->_action =
		static_cast<MacroActionSceneVisibility::Action>(value);
}

void MacroActionSceneVisibilityEdit::BlockUntilTransitionDoneChanged(int state)
{
	GUARD_LOADING_AND_LOCK();
	_entryData->_blockUntilTransitionDone = state;
}

void MacroActionSceneVisibilityEdit::SetWidgetVisibility()
{
	const bool hideDurationSelection =
		_entryData->_updateTransition &&
		IsFixedLengthTransition(
			_entryData->_transition.GetTransition());

	SetLayoutVisible(_durationLayout, !hideDurationSelection);

	_transitions->setEnabled(_entryData->_updateTransition);
	_duration->setEnabled(_entryData->_updateDuration);

	adjustSize();
	updateGeometry();
}

} // namespace advss