/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2019-2021, Raspberry Pi Ltd
 *
 * raspberrypi.cpp - Pipeline handler for Raspberry Pi devices
 */
#include <algorithm>
#include <assert.h>
#include <cmath>
#include <fcntl.h>
#include <memory>
#include <mutex>
#include <queue>
#include <unordered_set>
#include <utility>

#include <libcamera/base/file.h>
#include <libcamera/base/shared_fd.h>
#include <libcamera/base/utils.h>

#include <libcamera/camera.h>
#include <libcamera/control_ids.h>
#include <libcamera/formats.h>
#include <libcamera/ipa/raspberrypi_ipa_interface.h>
#include <libcamera/ipa/raspberrypi_ipa_proxy.h>
#include <libcamera/logging.h>
#include <libcamera/property_ids.h>
#include <libcamera/request.h>

#include <linux/bcm2835-isp.h>
#include <linux/media-bus-format.h>
#include <linux/videodev2.h>

#include "libcamera/internal/bayer_format.h"
#include "libcamera/internal/camera.h"
#include "libcamera/internal/camera_lens.h"
#include "libcamera/internal/camera_sensor.h"
#include "libcamera/internal/device_enumerator.h"
#include "libcamera/internal/framebuffer.h"
#include "libcamera/internal/ipa_manager.h"
#include "libcamera/internal/media_device.h"
#include "libcamera/internal/pipeline_handler.h"
#include "libcamera/internal/v4l2_videodevice.h"
#include "libcamera/internal/yaml_parser.h"

#include "delayed_controls.h"
#include "dma_heaps.h"
#include "rpi_stream.h"

using namespace std::chrono_literals;

namespace libcamera {

LOG_DEFINE_CATEGORY(RPI)

namespace {

constexpr unsigned int defaultRawBitDepth = 12;

/* Map of mbus codes to supported sizes reported by the sensor. */
using SensorFormats = std::map<unsigned int, std::vector<Size>>;

SensorFormats populateSensorFormats(std::unique_ptr<CameraSensor> &sensor)
{
	SensorFormats formats;

	for (auto const mbusCode : sensor->mbusCodes())
		formats.emplace(mbusCode, sensor->sizes(mbusCode));

	return formats;
}

bool isMonoSensor(std::unique_ptr<CameraSensor> &sensor)
{
	unsigned int mbusCode = sensor->mbusCodes()[0];
	const BayerFormat &bayer = BayerFormat::fromMbusCode(mbusCode);

	return bayer.order == BayerFormat::Order::MONO;
}

PixelFormat mbusCodeToPixelFormat(unsigned int mbus_code,
				  BayerFormat::Packing packingReq)
{
	BayerFormat bayer = BayerFormat::fromMbusCode(mbus_code);

	ASSERT(bayer.isValid());

	bayer.packing = packingReq;
	PixelFormat pix = bayer.toPixelFormat();

	/*
	 * Not all formats (e.g. 8-bit or 16-bit Bayer formats) can have packed
	 * variants. So if the PixelFormat returns as invalid, use the non-packed
	 * conversion instead.
	 */
	if (!pix.isValid()) {
		bayer.packing = BayerFormat::Packing::None;
		pix = bayer.toPixelFormat();
	}

	return pix;
}

V4L2DeviceFormat toV4L2DeviceFormat(const V4L2VideoDevice *dev,
				    const V4L2SubdeviceFormat &format,
				    BayerFormat::Packing packingReq)
{
	const PixelFormat pix = mbusCodeToPixelFormat(format.mbus_code, packingReq);
	V4L2DeviceFormat deviceFormat;

	deviceFormat.fourcc = dev->toV4L2PixelFormat(pix);
	deviceFormat.size = format.size;
	deviceFormat.colorSpace = format.colorSpace;
	return deviceFormat;
}

bool isRaw(const PixelFormat &pixFmt)
{
	/* This test works for both Bayer and raw mono formats. */
	return BayerFormat::fromPixelFormat(pixFmt).isValid();
}

double scoreFormat(double desired, double actual)
{
	double score = desired - actual;
	/* Smaller desired dimensions are preferred. */
	if (score < 0.0)
		score = (-score) / 8;
	/* Penalise non-exact matches. */
	if (actual != desired)
		score *= 2;

	return score;
}

V4L2SubdeviceFormat findBestFormat(const SensorFormats &formatsMap, const Size &req, unsigned int bitDepth)
{
	double bestScore = std::numeric_limits<double>::max(), score;
	V4L2SubdeviceFormat bestFormat;
	bestFormat.colorSpace = ColorSpace::Raw;

	constexpr float penaltyAr = 1500.0;
	constexpr float penaltyBitDepth = 500.0;

	/* Calculate the closest/best mode from the user requested size. */
	for (const auto &iter : formatsMap) {
		const unsigned int mbusCode = iter.first;
		const PixelFormat format = mbusCodeToPixelFormat(mbusCode,
								 BayerFormat::Packing::None);
		const PixelFormatInfo &info = PixelFormatInfo::info(format);

		for (const Size &size : iter.second) {
			double reqAr = static_cast<double>(req.width) / req.height;
			double fmtAr = static_cast<double>(size.width) / size.height;

			/* Score the dimensions for closeness. */
			score = scoreFormat(req.width, size.width);
			score += scoreFormat(req.height, size.height);
			score += penaltyAr * scoreFormat(reqAr, fmtAr);

			/* Add any penalties... this is not an exact science! */
			score += utils::abs_diff(info.bitsPerPixel, bitDepth) * penaltyBitDepth;

			if (score <= bestScore) {
				bestScore = score;
				bestFormat.mbus_code = mbusCode;
				bestFormat.size = size;
			}

			LOG(RPI, Debug) << "Format: " << size
					<< " fmt " << format
					<< " Score: " << score
					<< " (best " << bestScore << ")";
		}
	}

	return bestFormat;
}

enum class Unicam : unsigned int { Image, Embedded };
enum class Isp : unsigned int { Input, Output0, Output1, Stats };

} /* namespace */

class RPiCameraData : public Camera::Private
{
public:
	RPiCameraData(PipelineHandler *pipe)
		: Camera::Private(pipe), state_(State::Stopped),
		  supportsFlips_(false), flipsAlterBayerOrder_(false),
		  dropFrameCount_(0), buffersAllocated_(false), ispOutputCount_(0)
	{
	}

	~RPiCameraData()
	{
		freeBuffers();
	}

	void freeBuffers();
	void frameStarted(uint32_t sequence);

	int loadIPA(ipa::RPi::IPAInitResult *result);
	int configureIPA(const CameraConfiguration *config, ipa::RPi::IPAConfigResult *result);
	int loadPipelineConfiguration();

	void enumerateVideoDevices(MediaLink *link);

	void statsMetadataComplete(uint32_t bufferId, const ControlList &controls);
	void runIsp(uint32_t bufferId);
	void embeddedComplete(uint32_t bufferId);
	void setIspControls(const ControlList &controls);
	void setDelayedControls(const ControlList &controls, uint32_t delayContext);
	void setLensControls(const ControlList &controls);
	void setSensorControls(ControlList &controls);
	void unicamTimeout();

	/* bufferComplete signal handlers. */
	void unicamBufferDequeue(FrameBuffer *buffer);
	void ispInputDequeue(FrameBuffer *buffer);
	void ispOutputDequeue(FrameBuffer *buffer);

	void clearIncompleteRequests();
	void handleStreamBuffer(FrameBuffer *buffer, RPi::Stream *stream);
	void handleExternalBuffer(FrameBuffer *buffer, RPi::Stream *stream);
	void handleState();
	Rectangle scaleIspCrop(const Rectangle &ispCrop) const;
	void applyScalerCrop(const ControlList &controls);

	std::unique_ptr<ipa::RPi::IPAProxyRPi> ipa_;

	std::unique_ptr<CameraSensor> sensor_;
	SensorFormats sensorFormats_;
	/* Array of Unicam and ISP device streams and associated buffers/streams. */
	RPi::Device<Unicam, 2> unicam_;
	RPi::Device<Isp, 4> isp_;
	/* The vector below is just for convenience when iterating over all streams. */