/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2020, Laurent Pinchart
 * Copyright 2022 NXP
 *
 * V4L2 M2M Format converter
 */

#include "libcamera/internal/converter/converter_v4l2_m2m.h"

#include <algorithm>
#include <errno.h>
#include <limits.h>
#include <memory>
#include <set>

#include <libcamera/base/log.h>
#include <libcamera/base/signal.h>
#include <libcamera/base/utils.h>

#include <libcamera/framebuffer.h>
#include <libcamera/geometry.h>
#include <libcamera/stream.h>

#include "libcamera/internal/media_device.h"
#include "libcamera/internal/v4l2_request.h"
#include "libcamera/internal/v4l2_videodevice.h"

/**
 * \file converter/converter_v4l2_m2m.h
 * \brief V4L2 M2M based converter
 */

namespace libcamera {

LOG_DECLARE_CATEGORY(Converter)

namespace {

int getCropBounds(V4L2VideoDevice *device, Rectangle &minCrop,
		  Rectangle &maxCrop)
{
	Rectangle minC;
	Rectangle maxC;

	/* Find crop bounds */
	minC.width = 1;
	minC.height = 1;
	maxC.width = UINT_MAX;
	maxC.height = UINT_MAX;

	int ret = device->setSelection(V4L2_SEL_TGT_CROP, &minC);
	if (ret) {
		LOG(Converter, Error)
			<< "Could not query minimum selection crop: "
			<< strerror(-ret);
		return ret;
	}

	ret = device->getSelection(V4L2_SEL_TGT_CROP_BOUNDS, &maxC);
	if (ret) {
		LOG(Converter, Error)
			<< "Could not query maximum selection crop: "
			<< strerror(-ret);
		return ret;
	}

	/* Reset the crop to its maximum */
	ret = device->setSelection(V4L2_SEL_TGT_CROP, &maxC);
	if (ret) {
		LOG(Converter, Error)
			<< "Could not reset selection crop: "
			<< strerror(-ret);
		return ret;
	}

	minCrop = minC;
	maxCrop = maxC;
	return 0;
}

} /* namespace */

/* -----------------------------------------------------------------------------
 * V4L2M2MConverter::V4L2M2MStream
 */

V4L2M2MConverter::V4L2M2MStream::V4L2M2MStream(V4L2M2MConverter *converter, const Stream *stream)
	: converter_(converter), stream_(stream)
{
	m2m_ = std::make_unique<V4L2M2MDevice>(converter->deviceNode());

	m2m_->output()->bufferReady.connect(this, &V4L2M2MStream::outputBufferReady);
	m2m_->capture()->bufferReady.connect(this, &V4L2M2MStream::captureBufferReady);

	int ret = m2m_->open();
	if (ret < 0)
		m2m_.reset();
}

int V4L2M2MConverter::V4L2M2MStream::configure(const StreamConfiguration &inputCfg,
					       const StreamConfiguration &outputCfg)
{
	V4L2PixelFormat videoFormat =
		m2m_->output()->toV4L2PixelFormat(inputCfg.pixelFormat);

	V4L2DeviceFormat format;
	format.fourcc = videoFormat;
	format.size = inputCfg.size;
	format.planesCount = 1;
	format.planes[0].bpl = inputCfg.stride;

	int ret = m2m_->output()->setFormat(&format);
	if (ret < 0) {
		LOG(Converter, Error)
			<< "Failed to set input format: " << strerror(-ret);
		return ret;
	}

	if (format.fourcc != videoFormat || format.size != inputCfg.size ||
	    format.planes[0].bpl != inputCfg.stride) {
		LOG(Converter, Error)
			<< "Input format not supported (requested "
			<< inputCfg.size << "-" << videoFormat
			<< ", got " << format << ")";
		return -EINVAL;
	}

	/* Set the pixel format and size on the output. */
	videoFormat = m2m_->capture()->toV4L2PixelFormat(outputCfg.pixelFormat);
	format = {};
	format.fourcc = videoFormat;
	format.size = outputCfg.size;

	ret = m2m_->capture()->setFormat(&format);
	if (ret < 0) {
		LOG(Converter, Error)
			<< "Failed to set output format: " << strerror(-ret);
		return ret;
	}

	if (format.fourcc != videoFormat || format.size != outputCfg.size) {
		LOG(Converter, Error)
			<< "Output format not supported";
		return -EINVAL;
	}

	inputBufferCount_ = inputCfg.bufferCount;
	outputBufferCount_ = outputCfg.bufferCount;

	if (converter_->features() & Feature::InputCrop) {
		ret = getCropBounds(m2m_->output(), inputCropBounds_.first,
				    inputCropBounds_.second);
		if (ret)
			return ret;
	}

	return 0;
}

int V4L2M2MConverter::V4L2M2MStream::exportBuffers(unsigned int count,
						   std::vector<std::unique_ptr<FrameBuffer>> *buffers)
{
	return m2m_->capture()->exportBuffers(count, buffers);
}

int V4L2M2MConverter::V4L2M2MStream::start()
{
	int ret = m2m_->output()->importBuffers(inputBufferCount_);
	if (ret < 0)
		return ret;

	ret = m2m_->capture()->importBuffers(outputBufferCount_);
	if (ret < 0) {
		stop();
		return ret;
	}

	ret = m2m_->output()->streamOn();
	if (ret < 0) {
		stop();
		return ret;
	}

	ret = m2m_->capture()->streamOn();
	if (ret < 0) {
		stop();
		return ret;
	}

	return 0;
}

void V4L2M2MConverter::V4L2M2MStream::stop()
{
	m2m_->capture()->streamOff();
	m2m_->output()->streamOff();
	m2m_->capture()->releaseBuffers();
	m2m_->output()->releaseBuffers();
}

int V4L2M2MConverter::V4L2M2MStream::queueBuffers(FrameBuffer *input,
						  FrameBuffer *output,
						  const V4L2Request *request)
{
	int ret = m2m_->output()->queueBuffer(input, request);
	if (ret < 0)
		return ret;

	ret = m2m_->capture()->queueBuffer(output);
	if (ret < 0)
		return ret;

	return 0;
}

int V4L2M2MConverter::V4L2M2MStream::getInputSelection(unsigned int target, Rectangle *rect)
{
	return m2m_->output()->getSelection(target, rect);
}

int V4L2M2MConverter::V4L2M2MStream::setInputSelection(unsigned int target, Rectangle *rect)
{
	return m2m_->output()->setSelection(target, rect);
}

std::pair<Rectangle, Rectangle> V4L2M2MConverter::V4L2M2MStream::inputCropBounds()
{
	return inputCropBounds_;
}

std::string V4L2M2MConverter::V4L2M2MStream::logPrefix() const
{
	return stream_->configuration().toString();
}

void V4L2M2MConverter::V4L2M2MStream::outputBufferReady(FrameBuffer *buffer)
{
	auto it = converter_->queue_.find(buffer);
	if (it == converter_->queue_.end())
		return;

	if (!--it->second) {
		converter_->inputBufferReady.emit(buffer);
		converter_->queue_.erase(it);
	}
}

void V4L2M2MConverter::V4L2M2MStream::captureBufferReady(FrameBuffer *buffer)
{
	converter_->outputBufferReady.emit(buffer);
}

/* -----------------------------------------------------------------------------
 * V4L2M2MConverter
 */

/**
 * \class libcamera::V4L2M2MConverter
 * \brief The V4L2 M2M converter implements the converter interface based on
 * V4L2 M2M device.
*/

/**
 * \fn V4L2M2MConverter::V4L2M2MConverter
 * \brief Construct a V4L2M2MConverter instance
 * \param[in] media The media device implementing the converter
 */
V4L2M2MConverter::V4L2M2MConverter(std::shared_ptr<MediaDevice> media)
	: Converter(media), media_(media)
{
	if (deviceNode().empty())
		return;

	m2m_ = std::make_unique<V4L2M2MDevice>(deviceNode());
	int ret = m2m_->open();
	if (ret < 0) {
		m2m_.reset();
		return;
	}

	ret = getCropBounds(m2m_->output(), inputCropBounds_.first,
			    inputCropBounds_.second);
	if (!ret && inputCropBounds_.first != inputCropBounds_.second) {
		features_ |= Feature::InputCrop;

		LOG(Converter, Info)
			<< "Converter supports cropping on its input";
	}
}

/**
 * \fn libcamera::V4L2M2MConverter::loadConfiguration
 * \details \copydetails libcamera::Converter::loadConfiguration
 */

/**
 * \fn libcamera::V4L2M2MConverter::isValid
 * \details \copydetails libcamera::Converter::isValid
 */

/**
 * \fn libcamera::V4L2M2MConverter::formats
 * \details \copydetails libcamera::Converter::formats
 */
std::vector<PixelFormat> V4L2M2MConverter::formats(PixelFormat input)
{
	if (!m2m_)
		return {};

	/*
	 * Set the format on the input side (V4L2 output) of the converter to
	 * enumerate the conversion capabilities on its output (V4L2 capture).
	 */
	V4L2DeviceFormat v4l2Format;
	v4l2Format.fourcc = m2m_->output()->toV4L2PixelFormat(input);
	v4l2Format.size = { 1, 1 };

	int ret = m2m_->output()->setFormat(&v4l2Format);
	if (ret < 0) {
		LOG(Converter, Error)
			<< "Failed to set format: " << strerror(-ret);
		return {};
	}

	if (v4l2Format.fourcc != m2m_->output()->toV4L2PixelFormat(input)) {
		LOG(Converter, Debug)
			<< "Input format " << input << " not supported.";
		return {};
	}

	std::vector<PixelFormat> pixelFormats;

	for (const auto &format : m2m_->capture()->formats()) {
		PixelFormat pixelFormat = format.first.toPixelFormat();
		if (pixelFormat)
			pixelFormats.push_back(pixelFormat);
	}

	return pixelFormats;
}

/**
 * \copydoc libcamera::Converter::sizes
 */
SizeRange V4L2M2MConverter::sizes(const Size &input)
{
	if (!m2m_)
		return {};

	/*
	 * Set the size on the input side (V4L2 output) of the converter to
	 * enumerate the scaling capabilities on its output (V4L2 capture).
	 */
	V4L2DeviceFormat format;
	format.fourcc = V4L2PixelFormat();
	format.size = input;

	int ret = m2m_->output()->setFormat(&format);
	if (ret < 0) {
		LOG(Converter, Error)
			<< "Failed to set format: " << strerror(-ret);
		return {};
	}

	SizeRange sizes;

	format.size = { 1, 1 };
	ret = m2m_->capture()->setFormat(&format);
	if (ret < 0) {
		LOG(Converter, Error)
			<< "Failed to set format: " << strerror(-ret);
		return {};
	}

	sizes.min = format.size;

	format.size = { UINT_MAX, UINT_MAX };
	ret = m2m_->capture()->setFormat(&format);
	if (ret < 0) {
		LOG(Converter, Error)
			<< "Failed to set format: " << strerror(-ret);
		return {};
	}

	sizes.max = format.size;

	return sizes;
}

/**
 * \copydoc libcamera::Converter::strideAndFrameSize
 */
std::tuple<unsigned int, unsigned int>
V4L2M2MConverter::strideAndFrameSize(const PixelFormat &pixelFormat,
				     const Size &size)
{
	V4L2DeviceFormat format;
	format.fourcc = m2m_->capture()->toV4L2PixelFormat(pixelFormat);
	format.size = size;

	int ret = m2m_->capture()->tryFormat(&format);
	if (ret < 0)
		return std::make_tuple(0, 0);

	return std::make_tuple(format.planes[0].bpl, format.planes[0].size);
}

/**
 * \copydoc libcamera::Converter::adjustInputSize
 */
Size V4L2M2MConverter::adjustInputSize(const PixelFormat &pixFmt,
				       const Size &size, Alignment align)
{
	auto formats = m2m_->output()->formats();
	V4L2PixelFormat v4l2PixFmt = m2m_->output()->toV4L2PixelFormat(pixFmt);

	auto it = formats.find(v4l2PixFmt);
	if (it == formats.end()) {
		LOG(Converter, Info)
			<< "Unsupported pixel format " << pixFmt;
		return {};
	}

	return adjustSizes(size, it->second, align);
}

/**
 * \copydoc libcamera::Converter::adjustOutputSize
 */
Size V4L2M2MConverter::adjustOutputSize(const PixelFormat &pixFmt,
					const Size &size, Alignment align)
{
	auto formats = m2m_->capture()->formats();
	V4L2PixelFormat v4l2PixFmt = m2m_->capture()->toV4L2PixelFormat(pixFmt);

	auto it = formats.find(v4l2PixFmt);
	if (it == formats.end()) {
		LOG(Converter, Info)
			<< "Unsupported pixel format " << pixFmt;
		return {};
	}

	return adjustSizes(size, it->second, align);
}

Size V4L2M2MConverter::adjustSizes(const Size &cfgSize,
				   const std::vector<SizeRange> &ranges,
				   Alignment align)
{
	Size size = cfgSize;

	if (ranges.size() == 1) {
		/*
		 * The device supports either V4L2_FRMSIZE_TYPE_CONTINUOUS or
		 * V4L2_FRMSIZE_TYPE_STEPWISE.
		 */
		const SizeRange &range = *ranges.begin();

		size.width = std::clamp(size.width, range.min.width,
					range.max.width);
		size.height = std::clamp(size.height, range.min.height,
					 range.max.height);

		/*
		 * Check if any alignment is needed. If the sizes are already
		 * aligned, or the device supports V4L2_FRMSIZE_TYPE_CONTINUOUS
		 * with hStep and vStep equal to 1, we're done here.
		 */
		int widthR = size.width % range.hStep;
		int heightR = size.height % range.vStep;

		/* Align up or down according to the caller request. */

		if (widthR != 0)
			size.width = size.width - widthR
				   + ((align == Alignment::Up) ? range.hStep : 0);

		if (heightR != 0)
			size.height = size.height - heightR
				    + ((align == Alignment::Up) ? range.vStep : 0);
	} else {
		/*
		 * The device supports V4L2_FRMSIZE_TYPE_DISCRETE, find the
		 * size closer to the requested output configuration.
		 *
		 * The size ranges vector is not ordered, so we sort it first.
		 * If we align up, start from the larger element.
		 */
		std::vector<Size> sizes(ranges.size());
		std::transform(ranges.begin(), ranges.end(), std::back_inserter(sizes),
			       [](const SizeRange &range) { return range.max; });
		std::sort(sizes.begin(), sizes.end());

		if (align == Alignment::Up)
			std::reverse(sizes.begin(), sizes.end());

		/*
		 * Return true if s2 is valid according to the desired
		 * alignment: smaller than s1 if we align down, larger than s1
		 * if we align up.
		 */
		auto nextSizeValid = [](const Size &s1, const Size &s2, Alignment a) {
			return a == Alignment::Down
				? (s1.width > s2.width && s1.height > s2.height)
				: (s1.width < s2.width && s1.height < s2.height);
		};

		Size newSize;
		for (const Size &sz : sizes) {
			if (!nextSizeValid(size, sz, align))
				break;

			newSize = sz;
		}

		if (newSize.isNull()) {
			LOG(Converter, Error)
				<< "Cannot adjust " << cfgSize
				<< " to a supported converter size";
			return {};
		}

		size = newSize;
	}

	return size;
}

/**
 * \copydoc libcamera::Converter::configure
 */
int V4L2M2MConverter::configure(const StreamConfiguration &inputCfg,
				const std::vector<std::reference_wrapper<StreamConfiguration>> &outputCfgs)
{
	int ret = 0;

	streams_.clear();

	for (unsigned int i = 0; i < outputCfgs.size(); ++i) {
		const StreamConfiguration &cfg = outputCfgs[i];
		std::unique_ptr<V4L2M2MStream> stream =
			std::make_unique<V4L2M2MStream>(this, cfg.stream());

		if (!stream->isValid()) {
			LOG(Converter, Error)
				<< "Failed to create stream " << i;
			ret = -EINVAL;
			break;
		}

		ret = stream->configure(inputCfg, cfg);
		if (ret < 0)
			break;

		streams_.emplace(cfg.stream(), std::move(stream));
	}

	if (ret < 0) {
		streams_.clear();
		return ret;
	}

	return 0;
}

/**
 * \copydoc libcamera::Converter::isConfigured
 */
bool V4L2M2MConverter::isConfigured(const Stream *stream) const
{
	return streams_.find(stream) != streams_.end();
}

/**
 * \copydoc libcamera::Converter::exportBuffers
 */
int V4L2M2MConverter::exportBuffers(const Stream *stream, unsigned int count,
				    std::vector<std::unique_ptr<FrameBuffer>> *buffers)
{
	auto iter = streams_.find(stream);
	if (iter == streams_.end())
		return -EINVAL;

	return iter->second->exportBuffers(count, buffers);
}

/**
 * \copydoc libcamera::Converter::setInputCrop
 */
int V4L2M2MConverter::setInputCrop(const Stream *stream, Rectangle *rect)
{
	if (!(features_ & Feature::InputCrop))
		return -ENOTSUP;

	auto iter = streams_.find(stream);
	if (iter == streams_.end()) {
		LOG(Converter, Error) << "Invalid output stream";
		return -EINVAL;
	}

	return iter->second->setInputSelection(V4L2_SEL_TGT_CROP, rect);
}

/**
 * \fn libcamera::V4L2M2MConverter::inputCropBounds()
 * \copydoc libcamera::Converter::inputCropBounds()
 */

/**
 * \copydoc libcamera::Converter::inputCropBounds(const Stream *stream)
 */
std::pair<Rectangle, Rectangle>
V4L2M2MConverter::inputCropBounds(const Stream *stream)
{
	auto iter = streams_.find(stream);
	if (iter == streams_.end()) {
		LOG(Converter, Error) << "Invalid output stream";
		return {};
	}

	return iter->second->inputCropBounds();
}

/**
 * \copydoc libcamera::Converter::start
 */
int V4L2M2MConverter::start()
{
	int ret;

	for (auto &iter : streams_) {
		ret = iter.second->start();
		if (ret < 0) {
			stop();
			return ret;
		}
	}

	return 0;
}

/**
 * \copydoc libcamera::Converter::stop
 */
void V4L2M2MConverter::stop()
{
	for (auto &iter : streams_)
		iter.second->stop();
}

/**
 * \copydoc libcamera::Converter::validateOutput
 */
int V4L2M2MConverter::validateOutput(StreamConfiguration *cfg, bool *adjusted,
				     Alignment align)
{
	V4L2VideoDevice *capture = m2m_->capture();
	V4L2VideoDevice::Formats fmts = capture->formats();

	if (adjusted)
		*adjusted = false;

	PixelFormat fmt = cfg->pixelFormat;
	V4L2PixelFormat v4l2PixFmt = capture->toV4L2PixelFormat(fmt);

	auto it = fmts.find(v4l2PixFmt);
	if (it == fmts.end()) {
		it = fmts.begin();
		v4l2PixFmt = it->first;
		cfg->pixelFormat = v4l2PixFmt.toPixelFormat();

		if (adjusted)
			*adjusted = true;

		LOG(Converter, Info)
			<< "Converter output pixel format adjusted to "
			<< cfg->pixelFormat;
	}

	const Size cfgSize = cfg->size;
	cfg->size = adjustSizes(cfgSize, it->second, align);

	if (cfg->size.isNull())
		return -EINVAL;

	if (cfg->size.width != cfgSize.width ||
	    cfg->size.height != cfgSize.height) {
		LOG(Converter, Info)
			<< "Converter size adjusted to "
			<< cfg->size;
		if (adjusted)
			*adjusted = true;
	}

	return 0;
}

/**
 * \copydoc libcamera::Converter::queueBuffers
 */
int V4L2M2MConverter::queueBuffers(FrameBuffer *input,
				   const std::map<const Stream *, FrameBuffer *> &outputs,
				   const V4L2Request *request)
{
	std::set<FrameBuffer *> outputBufs;
	int ret;

	/*
	 * Validate the outputs as a sanity check: at least one output is
	 * required, all outputs must reference a valid stream and no two
	 * streams can reference same output framebuffers.
	 */
	if (outputs.empty())
		return -EINVAL;

	for (auto [stream, buffer] : outputs) {
		if (!buffer)
			return -EINVAL;

		outputBufs.insert(buffer);
	}

	if (outputBufs.size() != streams_.size())
		return -EINVAL;

	/* Queue the input and output buffers to all the streams. */
	for (auto [stream, buffer] : outputs) {
		ret = streams_.at(stream)->queueBuffers(input, buffer, request);
		if (ret < 0)
			return ret;
	}

	/*
	 * Add the input buffer to the queue, with the number of streams as a
	 * reference count. Completion of the input buffer will be signalled by
	 * the stream that releases the last reference.
	 */
	queue_.emplace(std::piecewise_construct,
		       std::forward_as_tuple(input),
		       std::forward_as_tuple(outputs.size()));

	return 0;
}

/**
 * \copydoc libcamera::MediaDevice::allocateRequests
 */
int V4L2M2MConverter::allocateRequests(unsigned int count,
				       std::vector<std::unique_ptr<V4L2Request>> *requests)
{
	/* \todo The acquire() must be moved to the right place. */
	media_->acquire();
	if (!media_->busy())
		LOG(Converter, Error)
			<< "MediaDevice must be valid.";
	int ret = media_->allocateRequests(count, requests);
	media_->release();
	return ret;
}

/**
 * \copydoc libcamera::MediaDevice::supportsRequests
 */
bool V4L2M2MConverter::supportsRequests()
{
	/* \todo The acquire() must be moved to the right place. */
	media_->acquire();
	if (!media_->busy())
		LOG(Converter, Error)
			<< "MediaDevice must be valid.";
	bool ret = media_->supportsRequests();
	media_->release();
	return ret;
}

/*
 * \todo This should be extended to include Feature::Flag to denote
 * what each converter supports feature-wise.
 */
static std::initializer_list<std::string> compatibles = {
	"mtk-mdp",
	"pxp",
};

REGISTER_CONVERTER("v4l2_m2m", V4L2M2MConverter, compatibles)

} /* namespace libcamera */