#include <config.h>
#include <opts.h>
#include <algorithm>
#include <unistd.h>
#include <iomanip>
#include <user/spMcRingBuffer.h>
#include <componentThread.h>
#include <asynchronousLoop.h>
#include <user/stimulusFrame.h>
#include "pcloudStimulusProducer.h"
#include <user/frameAssemblyDesc.h>

namespace smo {
namespace stim_buff {

extern const SmoCallbacks* smoHooksPtr;

// OpenCL kernels are used to collate and produce our StimFrames.
static SpMcRingBuffer::InputEngineConstraints openClInputConstraints(
	static_cast<size_t>(sysconf(_SC_PAGE_SIZE)), sizeof(void *));

PcloudStimulusProducer::PcloudStimulusProducer(
	const std::shared_ptr<device::DeviceAttachmentSpec> &deviceAttachmentSpec,
	std::shared_ptr<livoxProto1::Device> &device,
	const PcloudFormatDesc& formatDesc,
	size_t nDgramsPerStagingBufferFrame)
:	StimulusProducer(
		deviceAttachmentSpec,
		device->componentThread->getIoService()),
device(device),
formatDesc(formatDesc),
openClCollatingAndMeshingEngine(*this),
assemblyBuffer(
	StagingBuffer::IOEngineConstraints::ioUringConstraints,
	StagingBuffer::IOEngineConstraints::openClInputConstraints,
	nDgramsPerStagingBufferFrame),
ioUringAssemblyEngine(*this, nDgramsPerStagingBufferFrame),
collationBuffer(
	StagingBuffer::IOEngineConstraints::openClInputConstraints,
	StagingBuffer::IOEngineConstraints::openClInputConstraints,
	nDgramsPerStagingBufferFrame)
{
	if (smoHooksPtr->OptionParser_getOptions().verbose)
	{
		std::cout << __func__ << ": assembly buffer : "
			<< assemblyBuffer.stringify()
			<< "\n\tcollation buffer : " << collationBuffer.stringify()
			<< "\n";
	}

	std::cout << __func__ << ": Device's component thread is "
		<< device->componentThread->name << std::endl;

#ifndef CONFIG_WORLD_USE_BODY_THREAD
	if (smoHooksPtr->ComponentThread_getSelf()->id != ComponentThread::WORLD)
#else
	if (smoHooksPtr->ComponentThread_getSelf()->id != ComponentThread::BODY)
#endif
	{
		std::string errMsg = std::string(__func__) +
			": PcloudStimulusProducer constructor called on non-world/body thread " +
			smoHooksPtr->ComponentThread_getSelf()->name;

		std::cout << errMsg << std::endl;
	//		throw std::runtime_error(errMsg);
	}
}

void PcloudStimulusProducer::start()
{
	std::cout << __func__ << ": Starting PcloudStimulusProducer for device "
		<< device->discoveredDevice.deviceIdentifier << std::endl;

	// Call ioUringAssemblyEngine setup() as the first step
	if (!ioUringAssemblyEngine.setup())
	{
		std::cout <<__func__ <<"Failed to setup() "
			<<"IOUringAssemblyEngine.\n";
		return;
	}

	if (!openClCollatingAndMeshingEngine.setup())
	{
		std::cout <<__func__ <<"Failed to setup() "
			<<"OClCollMeshEngine.\n";
		return;
	}

	// Call base class start() as the final step
	StimulusProducer::start();
}

void PcloudStimulusProducer::stop()
{
	std::cout << __func__ << ": Stopping PcloudStimulusProducer for device "
		<< device->discoveredDevice.deviceIdentifier << std::endl;

	// Call base class stop() as the first step
	StimulusProducer::stop();
	// Call ioUringAssemblyEngine stop() as the final step
	openClCollatingAndMeshingEngine.finalize();
	ioUringAssemblyEngine.finalize();
}

void produceStimFrameAck(void)
{
}

// Helper function to parse histbuffMs from device attachment spec
static int parseHistbuffMs(
	const std::shared_ptr<device::DeviceAttachmentSpec>& spec)
{
	int histbuffMs = 30000;  // Default: 30000ms (30 seconds)
	const std::vector<std::string> histbuffParamNames = {
		"history-buffer-duration-ms",
		"hist-buff-duration-ms",
		"histbuff-duration-ms",
		"histbuff-ms"
	};

	// Loop through synonyms in reverse order; lattermost synonym wins.
	for (auto synIt = histbuffParamNames.rbegin();
		synIt != histbuffParamNames.rend(); ++synIt)
	{
		const auto& paramName = *synIt;
		try {
			histbuffMs = device::DeviceAttachmentSpec
				::parseRequiredParamAsInt(
					spec->qualeIfaceApiParams, paramName);
			break; // Found and parsed successfully
		} catch (const std::exception&) {
			// Parameter not found or parse error, continue to next synonym
			continue;
		}
	}

	return histbuffMs;
}

std::shared_ptr<StimulusBuffer>
PcloudStimulusProducer::getAttachedStimulusBuffer(
	const std::shared_ptr<device::DeviceAttachmentSpec>& spec) const
{
	// Call base class implementation
	auto buffer = StimulusProducer::getAttachedStimulusBuffer(spec);
	if (!buffer)
	{
		return nullptr;
	}

	// Optionally validate/upcast the buffer type matches expected type
	// based on qualeIfaceApi (for type safety)
	const std::string& qualeIfaceApi = spec->qualeIfaceApi;
	if (qualeIfaceApi == "mesh")
	{
		if (std::dynamic_pointer_cast<MeshStimulusBuffer>(buffer))
			{ return buffer; }
	}
	else if (qualeIfaceApi == "pcloudIntensity")
	{
		if (std::dynamic_pointer_cast<PcloudIntensityStimulusBuffer>(buffer))
			{ return buffer; }
	}
	else if (qualeIfaceApi == "pcloudAmbience")
	{
		if (std::dynamic_pointer_cast<PcloudAmbienceStimulusBuffer>(buffer))
			{ return buffer; }
	}

	// Type mismatch - return nullptr
	return nullptr;
}

std::shared_ptr<StimulusBuffer>
PcloudStimulusProducer::getOrCreateAttachedStimulusBuffer(
	const std::shared_ptr<device::DeviceAttachmentSpec>& deviceAttachmentSpec
	)
{
	// Check if buffer already exists (idempotent)
	auto existingBuffer = getAttachedStimulusBuffer(deviceAttachmentSpec);
	if (existingBuffer)
		{ return existingBuffer; }

	// Parse histbuffMs from device attachment spec
	int histbuffMs = parseHistbuffMs(deviceAttachmentSpec);

	// Parse qualeIfaceApi to determine buffer type
	const std::string& qualeIfaceApi = deviceAttachmentSpec->qualeIfaceApi;

	if (qualeIfaceApi == "mesh")
	{
		auto meshBuffer = std::make_shared<MeshStimulusBuffer>(
			*this, deviceAttachmentSpec, histbuffMs, openClInputConstraints);

		meshStimulusBuffer = meshBuffer;
		attachedStimulusBuffers.push_back(meshBuffer);
		return meshBuffer;
	}
	else if (qualeIfaceApi == "pcloudIntensity")
	{
		auto intensityBuffer = std::make_shared<PcloudIntensityStimulusBuffer>(
			*this, deviceAttachmentSpec, histbuffMs, openClInputConstraints);

		intensityStimulusBuffer = intensityBuffer;
		attachedStimulusBuffers.push_back(intensityBuffer);
		return intensityBuffer;
	}
	else if (qualeIfaceApi == "pcloudAmbience")
	{
		auto ambienceBuffer = std::make_shared<PcloudAmbienceStimulusBuffer>(
			*this, deviceAttachmentSpec, histbuffMs, openClInputConstraints);

		ambienceStimulusBuffer = ambienceBuffer;
		attachedStimulusBuffers.push_back(ambienceBuffer);
		return ambienceBuffer;
	}
	else
	{
		throw std::runtime_error(
			"Unsupported qualeIfaceApi: '" + qualeIfaceApi + "' for "
			"PcloudStimulusProducer. "
			"Supported values: mesh, pcloudIntensity, pcloudAmbience");
	}
}

void PcloudStimulusProducer::stimFrameProductionTimesliceInd()
{
	produceFrameReq({nullptr, nullptr});
}

class PcloudStimulusProducer::ProduceFrameReq
:	public PostedAsynchronousContinuation<produceFrameReqCbFn>
{
private:
	PcloudStimulusProducer& pcloudProducer;
	AsynchronousLoop frameAssemblyResult;
	StimulusFrame& stimulusFrame;

public:
	ProduceFrameReq(
		PcloudStimulusProducer& producer,
		const std::shared_ptr<ComponentThread>& caller,
		Callback<produceFrameReqCbFn> cb)
	:	PostedAsynchronousContinuation<produceFrameReqCbFn>(caller, cb),
	pcloudProducer(producer),
	frameAssemblyResult(0),
	stimulusFrame(producer.tempStimulusFrame)
	{}

public:
	void callOriginalCallback()
	{
		pcloudProducer.allowNextStimulusFrame();
		callOriginalCb();
	}

public:
	void produceFrameReq1_doAssemble_posted(
		std::shared_ptr<ProduceFrameReq> context)
	{
		SpinLock::Guard lock(pcloudProducer.shouldContinueLock);
		if (!pcloudProducer.shouldContinue)
		{
			callOriginalCallback();
			return;
		}

		pcloudProducer.ioUringAssemblyEngine.assembleFrameReq(
			{context, std::bind(
				&ProduceFrameReq::produceFrameReq2_assembleDone,
				context.get(), context,
				std::placeholders::_1, std::placeholders::_2)});
	}

	void produceFrameReq2_assembleDone(
		std::shared_ptr<ProduceFrameReq> context,
		bool success, AsynchronousLoop loop)
	{
		SpinLock::Guard lock(pcloudProducer.shouldContinueLock);
		if (!pcloudProducer.shouldContinue)
		{
			callOriginalCallback();
			return;
		}

		if (!success)
		{
			std::cerr << __func__ << ": Failed to assemble frame" << std::endl;
			callOriginalCallback();
			return;
		}

		context->frameAssemblyResult = loop;

		pcloudProducer.openClCollatingAndMeshingEngine.compactCollateAndMeshFrameReq(
			loop, stimulusFrame,
			{context, std::bind(
				&ProduceFrameReq::produceFrameReq3_compactCollateDone,
				context.get(), context,
				std::placeholders::_1, std::placeholders::_2)});
	}

	void produceFrameReq3_compactCollateDone(
		[[maybe_unused]] std::shared_ptr<ProduceFrameReq> context,
		bool success, StimulusFrame& /*stimulusFrame*/)
	{
		SpinLock::Guard lock(pcloudProducer.shouldContinueLock);
		if (!pcloudProducer.shouldContinue)
		{
			callOriginalCallback();
			return;
		}

		if (!success) {
			std::cerr << __func__ << ": Failed to compact and collate frame" << std::endl;
		} else {
			std::cout << __func__ << ": Successfully compacted and collated frame" << std::endl;
		}

		// Print kernel execution durations
		auto compactDuration = pcloudProducer.openClCollatingAndMeshingEngine.getCompactKernelDuration();
		auto collateDuration = pcloudProducer.openClCollatingAndMeshingEngine.getCollateKernelDuration();
		std::cout << __func__ << ": compactKernelDuration=" << compactDuration.count()
			<< "ms, collateKernelDuration=" << collateDuration.count() << "ms" << std::endl;

		callOriginalCallback();
	}
};

void PcloudStimulusProducer::produceFrameReq(
	smo::Callback<produceFrameReqCbFn> callback)
{
	/**	EXPLANATION:
	 * We shouldn't acquire the StimulusProducer::shouldContinueLock here because
	 * this function is called from
	 * StimulusProducer::stimFrameProductionTimesliceInd(), which is already
	 * holding the lock.
	 */
	auto caller = smoHooksPtr->ComponentThread_getSelf();
	auto request = std::make_shared<ProduceFrameReq>(
		*this, caller, std::move(callback));

	// Post the doAssemble method to the component thread
	device->componentThread->getIoService().post(
		STC(std::bind(
			&ProduceFrameReq::produceFrameReq1_doAssemble_posted,
			request.get(), request)));
}

} // namespace stim_buff
} // namespace smo