/* SPDX-License-Identifier: Apache-2.0 */
/*
 * Copyright (C) 2020, Google Inc.
 *
 * ipu3.cpp - IPU3 Image Processing Algorithms
 */

#include <stdint.h>
#include <sys/mman.h>

#include <linux/intel-ipu3.h>
#include <linux/v4l2-controls.h>

#include <libcamera/buffer.h>
#include <libcamera/control_ids.h>
#include <libcamera/ipa/ipa_interface.h>
#include <libcamera/ipa/ipa_module_info.h>
#include <libcamera/ipa/ipu3_ipa_interface.h>
#include <libcamera/request.h>

#include <libcamera/base/log.h>

#include "libcamera-helpers/mapped_buffer.h"

namespace libcamera {

LOG_DEFINE_CATEGORY(IPAIPU3)

namespace ipa::ipu3 {

class IPAIPU3 : public IPAIPU3Interface
{
public:
	int init([[maybe_unused]] const IPASettings &settings) override
	{
		return 0;
	}
	int start() override;
	void stop() override {}

	int configure(const IPAConfigInfo &configInfo) override;

	void mapBuffers(const std::vector<IPABuffer> &buffers) override;
	void unmapBuffers(const std::vector<unsigned int> &ids) override;
	void processEvent(const IPU3Event &event) override;

private:
	void processControls(unsigned int frame, const ControlList &controls);
	void fillParams(unsigned int frame, ipu3_uapi_params *params);
	void parseStatistics(unsigned int frame,
			     int64_t frameTimestamp,
			     const ipu3_uapi_stats_3a *stats);

	void setControls(unsigned int frame);

	std::map<unsigned int, MappedFrameBuffer> buffers_;

	ControlInfoMap ctrls_;

	IPACameraSensorInfo sensorInfo_;

	/* Camera sensor controls. */
	uint32_t exposure_;
	uint32_t minExposure_;
	uint32_t maxExposure_;
	uint32_t gain_;
	uint32_t minGain_;
	uint32_t maxGain_;
};

int IPAIPU3::start()
{
	setControls(0);

	return 0;
}

int IPAIPU3::configure(const IPAConfigInfo &configInfo)
{
	if (configInfo.entityControls.empty()) {
		LOG(IPAIPU3, Error) << "No controls provided";
		return -ENODATA;
	}

	sensorInfo_ = configInfo.sensorInfo;

	ctrls_ = configInfo.entityControls.at(0);

	const auto itExp = ctrls_.find(V4L2_CID_EXPOSURE);
	if (itExp == ctrls_.end()) {
		LOG(IPAIPU3, Error) << "Can't find exposure control";
		return -EINVAL;
	}

	const auto itGain = ctrls_.find(V4L2_CID_ANALOGUE_GAIN);
	if (itGain == ctrls_.end()) {
		LOG(IPAIPU3, Error) << "Can't find gain control";
		return -EINVAL;
	}

	minExposure_ = std::max(itExp->second.min().get<int32_t>(), 1);
	maxExposure_ = itExp->second.max().get<int32_t>();
	exposure_ = maxExposure_;

	minGain_ = std::max(itGain->second.min().get<int32_t>(), 1);
	maxGain_ = itGain->second.max().get<int32_t>();
	gain_ = maxGain_;

	return 0;
}

void IPAIPU3::mapBuffers(const std::vector<IPABuffer> &buffers)
{
	for (const IPABuffer &buffer : buffers) {
		const FrameBuffer fb(buffer.planes);
		buffers_.emplace(buffer.id,
				 MappedFrameBuffer(&fb, PROT_READ | PROT_WRITE));
	}
}

void IPAIPU3::unmapBuffers(const std::vector<unsigned int> &ids)
{
	for (unsigned int id : ids) {
		auto it = buffers_.find(id);
		if (it == buffers_.end())
			continue;

		buffers_.erase(it);
	}
}

void IPAIPU3::processEvent(const IPU3Event &event)
{
	switch (event.op) {
	case EventProcessControls: {
		processControls(event.frame, event.controls);
		break;
	}
	case EventStatReady: {
		auto it = buffers_.find(event.bufferId);
		if (it == buffers_.end()) {
			LOG(IPAIPU3, Error) << "Could not find stats buffer!";
			return;
		}

		Span<uint8_t> mem = it->second.maps()[0];
		const ipu3_uapi_stats_3a *stats =
			reinterpret_cast<ipu3_uapi_stats_3a *>(mem.data());

		parseStatistics(event.frame, event.frameTimestamp, stats);
		break;
	}
	case EventFillParams: {
		auto it = buffers_.find(event.bufferId);
		if (it == buffers_.end()) {
			LOG(IPAIPU3, Error) << "Could not find param buffer!";
			return;
		}

		Span<uint8_t> mem = it->second.maps()[0];
		ipu3_uapi_params *params =
			reinterpret_cast<ipu3_uapi_params *>(mem.data());

		fillParams(event.frame, params);
		break;
	}
	default:
		LOG(IPAIPU3, Error) << "Unknown event " << event.op;
		break;
	}
}

void IPAIPU3::processControls([[maybe_unused]] unsigned int frame,
			      [[maybe_unused]] const ControlList &controls)
{
	/* \todo Start processing for 'frame' based on 'controls'. */
}

void IPAIPU3::fillParams(unsigned int frame, ipu3_uapi_params *params)
{
	/* Prepare parameters buffer. */
	memset(params, 0, sizeof(*params));

	/* \todo Fill in parameters buffer. */

	IPU3Action op;
	op.op = ActionParamFilled;

	queueFrameAction.emit(frame, op);
}

void IPAIPU3::parseStatistics(unsigned int frame,
			      [[maybe_unused]] int64_t frameTimestamp,
			      [[maybe_unused]] const ipu3_uapi_stats_3a *stats)
{
	ControlList ctrls(controls::controls);

	/* \todo React to statistics and update internal state machine. */
	/* \todo Add meta-data information to ctrls. */

	IPU3Action op;
	op.op = ActionMetadataReady;
	op.controls = ctrls;

	queueFrameAction.emit(frame, op);
}

void IPAIPU3::setControls(unsigned int frame)
{
	IPU3Action op;
	op.op = ActionSetSensorControls;

	ControlList ctrls(ctrls_);
	ctrls.set(V4L2_CID_EXPOSURE, static_cast<int32_t>(exposure_));
	ctrls.set(V4L2_CID_ANALOGUE_GAIN, static_cast<int32_t>(gain_));
	op.controls = ctrls;

	queueFrameAction.emit(frame, op);
}

} /* namespace ipa::ipu3 */

/*
 * External IPA module interface
 */

extern "C" {
const struct IPAModuleInfo ipaModuleInfo = {
	IPA_MODULE_API_VERSION,
	1,
	"PipelineHandlerIPU3",
	"ipu3",
};

IPAInterface *ipaCreate()
{
	return new ipa::ipu3::IPAIPU3();
}
}

} /* namespace libcamera */