#include <cmath>
#include <cstring>

#include "raptor_eagle_cameralink.h"
#include "raptor_eagle_ccd.h"
#include "raptor_eagle_exception.h"

#include <common/adc_utils.h>

namespace details
{

// compute checksum as XOR operation along elements of byte array
template <std::ranges::input_range R>
auto computeChecksum(const R& bytes, bool final_etx = true)
    requires std::convertible_to<std::ranges::range_value_t<R>, char>
{
    std::ranges::range_value_t<R> res = 0;

    if (std::ranges::size(bytes) == 0) {
        return res;
    }

    for (auto& byte : bytes) {
        res ^= byte;
    }

    if (final_etx) {
        res ^= CL_ETX;
    }

    return res;
}

// assume that least significant byte is the last one in 'bytes'
// only the first 5 elements of the input range are taken
template <std::ranges::input_range R>
size_t convert40BitToCounts(const R& bytes)
    requires std::same_as<std::ranges::range_value_t<R>, unsigned char>
{
    // size_t counts = 0, i = std::ranges::size(bytes);

    // for (auto& byte : bytes| std::views::take(5)) {
    //     counts += byte << (--i * 8);
    // }

    if (std::ranges::size(bytes) == 0)
        return 0;

    size_t counts = *bytes.begin();
    for (auto& byte : bytes | std::views::drop(1) | std::views::take(4)) {
        counts <<= 8;
        counts |= byte;
    }

    return counts;
}


// NOTE: it is assumed little-endian host's platform!!!
// return an range with least significant byte in the end of the range
template <std::ranges::output_range<unsigned char> R = std::vector<unsigned char>>
R convertCountsTo40Bit(uint64_t counts)
{
    R res;

    auto sp = std::span(reinterpret_cast<unsigned char*>(&counts), 8);

    // least significant byte in the end of the output range
    std::ranges::copy(sp | std::views::take(5) | std::views::reverse, std::back_inserter(res));

    return res;
}


// assume that least significant byte is the last one in 'bytes'
// only the first 2 elements of the input range are taken
template <std::ranges::input_range R>
uint16_t convert12BitToUInt(const R& bytes)
    requires std::same_as<std::ranges::range_value_t<R>, unsigned char>
{
    if (std::ranges::size(bytes) == 0)
        return 0;

    auto v = bytes | std::views::reverse | std::views::take(2);

    if (std::ranges::size(bytes) > 1) {
        return *v.begin() + ((*(++v.begin()) & 0x0F) << 8);
    } else {
        return *v.begin();
    }
}


// NOTE: it is assumed little-endian host's platform!!!
// return an range with least significant byte in the end of the range
template <std::ranges::output_range<unsigned char> R = std::vector<unsigned char>>
R convertUIntTo12Bit(uint16_t counts)
{
    R res;

    auto sp = std::span(reinterpret_cast<unsigned char*>(&counts), 2);

    // least significant byte in the end of the output range
    std::ranges::copy(sp | std::views::reverse, std::back_inserter(res));

    return res;
}


}  // namespace details


#define DEFAULT_EPIX_VIDEO_FMT_FILE "raptor_eagle-v.fmt"

/*  CONSTRUCTORS AND DESTRUCTOR  */

RaptorEagleCCD::RaptorEagleCCD(const adc::traits::adc_input_char_range auto& epix_video_fmt_filename,
                               std::shared_ptr<spdlog::logger> logger)
    : base_t("EagleCCD"),
      adc::AdcSpdlogLogger(logger),
      _epixFmtVideoFilename(),
      _cameraUnitmap(1),    // by default only the single camera
      _clCommandAckBit(1),  // enable by default (at camera boot up)
      _clChecksumBit(1)     // enable by default (at camera boot up)

{
    addMarkToPattern("EAGLE-CCD");

    std::ranges::copy(epix_video_fmt_filename, std::back_inserter(_epixFmtVideoFilename));

    logDebug("CTOR: Create RaptorEagleCCD class instance");
    if (_epixFmtVideoFilename.empty()) {
        logDebug("Video format filename is not set! Use of default: {}", DEFAULT_EPIX_VIDEO_FMT_FILE);
    } else {
        logDebug("Set video format filename: {}", _epixFmtVideoFilename);
    }
}


RaptorEagleCCD::RaptorEagleCCD(std::shared_ptr<spdlog::logger> logger)
    : RaptorEagleCCD(std::string_view(), std::move(logger))
{
}


RaptorEagleCCD::~RaptorEagleCCD()
{
    logDebug("DTOR: Delete RaptorEagleCCD class instance");
}



/*                                  PUBLIC METHODS                                  */


/*   system state get/set   */

std::bitset<8> RaptorEagleCCD::getSystemState()
{
    std::lock_guard lock_guard(_camlinkMutex);

    byte_seq_t ans;

    clWrite({0x49});
    clReadAndCheckAck(ans);

    std::bitset<8> bits{ans[0]};

    logDebug("Get system state as 0b{} bits", bits.to_string());

    _clCommandAckBit = bits.test(CL_SYSTEM_STATUS_ACK_BIT) ? 1 : 0;
    _clChecksumBit = bits.test(CL_SYSTEM_STATUS_CK_SUM_BIT) ? 1 : 0;

    return bits;
}


void RaptorEagleCCD::setSystemState(const std::bitset<8>& bits)
{
    std::lock_guard lock_guard(_camlinkMutex);

    logDebug("Try to set system state to 0b{} bits", bits.to_string());

    uint8_t status = static_cast<uint8_t>(bits.to_ulong());

    clWrite({0x4F, status});
    clReadAndCheckAck();

    _clCommandAckBit = bits.test(CL_SYSTEM_STATUS_ACK_BIT) ? 1 : 0;
    _clChecksumBit = bits.test(CL_SYSTEM_STATUS_CK_SUM_BIT) ? 1 : 0;
}


void RaptorEagleCCD::setSystemStateBit(const size_t pos)
{
    std::lock_guard lock_guard(_camlinkMutex);

    auto bits = getSystemState();

    logDebug("Set system state bit {}", details::cl_system_status_bit(pos));
    bits.set(pos);

    setSystemState(bits);
}


void RaptorEagleCCD::clearSystemStateBit(const size_t pos)
{
    std::lock_guard lock_guard(_camlinkMutex);

    auto bits = getSystemState();

    logDebug("Clear system state bit {}", details::cl_system_status_bit(pos));
    bits.reset(pos);

    setSystemState(bits);
}


void RaptorEagleCCD::flipSystemStateBit(const size_t pos)
{
    std::lock_guard lock_guard(_camlinkMutex);

    auto bits = getSystemState();

    logDebug("Flip system state bit {}", details::cl_system_status_bit(pos));
    bits.flip(pos);

    setSystemState(bits);
}


// FPGS control register get/set

std::bitset<8> RaptorEagleCCD::getFPGAState()
{
    std::lock_guard log_guard(_camlinkMutex);

    auto ans = readRegisters({0x00});

    std::bitset<8> bits{ans[0]};

    logDebug("Get FPGS control register as 0b{} bits", bits.to_string());

    return bits;
}


void RaptorEagleCCD::setFPGAState(const std::bitset<8>& bits)
{
    std::lock_guard lock_guard(_camlinkMutex);

    logDebug("Try to set FPGA control register to 0b{} bits", bits.to_string());

    uint8_t status = static_cast<uint8_t>(bits.to_ulong());

    writeRegisters({0x00}, {status});
}


void RaptorEagleCCD::setFPGAStateBit(const size_t pos)
{
    std::lock_guard lock_guard(_camlinkMutex);

    auto bits = getFPGAState();

    logDebug("Set FPGA control register bit {}", details::cl_fpga_ctrl_reg_bit(pos));
    bits.set(pos);

    setFPGAState(bits);
}


void RaptorEagleCCD::clearFPGAStateBit(const size_t pos)
{
    std::lock_guard lock_guard(_camlinkMutex);

    auto bits = getFPGAState();

    logDebug("Clear FPGA control register bit {}", details::cl_fpga_ctrl_reg_bit(pos));
    bits.reset(pos);

    setFPGAState(bits);
}


void RaptorEagleCCD::flipFPGAStateBit(const size_t pos)
{
    std::lock_guard lock_guard(_camlinkMutex);

    auto bits = getFPGAState();

    logDebug("Flip FPGA control register bit {}", details::cl_fpga_ctrl_reg_bit(pos));
    bits.flip(pos);

    setFPGAState(bits);
}


/*  PRIVATE METHODS  */

void RaptorEagleCCD::initCamera(int unitmap)
{
    logInfo("Try to init camera with unitmap: {} ...", unitmap);

    if (unitmap < 0) {
        throw std::system_error(RaptorEagleCCDError::ERROR_INVALID_UNITMAP);
    }

    _cameraUnitmap = unitmap;

    // configure CameraLink serial connection
    xclibApiCall(pxd_serialConfigure(_cameraUnitmap, 0, CL_DEFAULT_BAUD_RATE, CL_DEFAULT_DATA_BITS, 0,
                                     CL_DEFAULT_STOP_BIT, 0, 0, 0),
                 std::format("pxd_serialConfigure({}, 0, {}, {}, 0, {}, 0, 0, 0)", _cameraUnitmap, CL_DEFAULT_BAUD_RATE,
                             CL_DEFAULT_DATA_BITS, CL_DEFAULT_STOP_BIT));

    logInfo("Camera with unitmap '{}' is initialized", _cameraUnitmap);
}


void RaptorEagleCCD::openPIXCI()
{
    if (_epixFmtVideoFilename.size()) {
        xclibApiCall(pxd_PIXCIopen("", nullptr, _epixFmtVideoFilename.c_str()),
                     std::format("pxd_PIXCIopen(\"\", NULL, {})", _epixFmtVideoFilename));
    } else {
        xclibApiCall(pxd_PIXCIopen("", "DEFAULT", ""), "pxd_PIXCIopen(\"\", \"DEFAULT\", \"\")");

#include DEFAULT_EPIX_VIDEO_FMT_FILE  // exported from XCAP (Linux 64-bit!): bin 1x1, full CCD frame
        pxd_videoFormatAsIncludedInit(0);
        xclibApiCall(pxd_videoFormatAsIncluded(0), "pxd_videoFormatAsIncluded(0)");
    }
}


void RaptorEagleCCD::closePIXCI()
{
    // no exception here!!!
    xclibApiCall<true>(pxd_PIXCIclose(), "pxd_PIXCIclose()");
}



/*  CameraLink-RELATED METHODS  */

size_t RaptorEagleCCD::clRead(byte_seq_t& bytes)
{
    std::lock_guard lock_guard(_camlinkMutex);

    size_t nbytes;

    // how many byte are available
    xclibApiCall(nbytes = pxd_serialRead(_cameraUnitmap, 0, nullptr, 0),
                 std::format("pxd_serialRead({}, 0, NULL, 0)", _cameraUnitmap));

    if (!nbytes) {
        logWarn("There are no bytes in Rx-buffer! Nothing to do!");
        return 0;
    }

    nbytes += _clCommandAckBit + _clChecksumBit;

    if (bytes.size() < nbytes) {
        bytes.resize(nbytes);
    }

    xclibApiCall(pxd_serialRead(_cameraUnitmap, 0, (char*)bytes.data(), nbytes),
                 std::format("pxd_serialRead({}, 0, {}, {})", _cameraUnitmap, (void*)bytes.data(), nbytes));


    if (_loggerSPtr->level() == spdlog::level::trace) {
        std::string s;
        adc::utils::AdcCharRangeFromValueRange(s, bytes, std::string_view(", "));

        logTrace("Received from controller: [{}]", s);
    }

    return nbytes;
}

size_t RaptorEagleCCD::clReadAndCheckAck(byte_seq_t& bytes)
{
    std::lock_guard lock_guard(_camlinkMutex);

    auto nbytes = clRead(bytes);

    if (_clCommandAckBit && nbytes) {
        auto ack = *(bytes.end() - 1 - _clChecksumBit);
        if (ack != CL_ETX) {
            throw std::error_code(ack, RaptorEagleControllerErrorCategory::get());
        }
    }

    return nbytes;
}

size_t RaptorEagleCCD::clReadAndCheckAck()
{
    byte_seq_t bytes;

    return clReadAndCheckAck(bytes);
}


// 'bytes' must contain only data without trailing ETX and checksum bytes!
size_t RaptorEagleCCD::clWrite(const byte_seq_t& bytes)
{
    std::lock_guard lock_guard(_camlinkMutex);

    static unsigned char etx_checksum_bytes[] = {CL_ETX, 0xFF};

    if (bytes.empty()) {
        logWarn("An empty transmitted byte sequence! Nothing to do!");
        return 0;
    }

    if (_loggerSPtr->level() == spdlog::level::trace) {
        std::string s;
        adc::utils::AdcCharRangeFromValueRange(s, bytes, std::string_view(", "));

        logTrace("Send to controller: [{}]", s);
    }


    size_t nbytes, tr_nbytes = 1 + _clChecksumBit;

    // how many bytes are available in Tx-buffer
    xclibApiCall(nbytes = pxd_serialWrite(_cameraUnitmap, 0, nullptr, 0),
                 std::format("pxd_serialWrite({}, 0, NULL, 0)", _cameraUnitmap));

    if (nbytes) {
        if (nbytes < (bytes.size() + tr_nbytes)) {
            logWarn(
                "Not enough of available space in the internal Tx-buffer (needs = {}, available = {})! Nothing to do!",
                bytes.size() + tr_nbytes, nbytes);
            nbytes = 0;
        } else {
            if (_clChecksumBit) {
                etx_checksum_bytes[1] = details::computeChecksum(bytes);
            }

            xclibApiCall(
                nbytes = pxd_serialWrite(_cameraUnitmap, 0, (char*)bytes.data(), bytes.size()),
                std::format("pxd_serialWrite({}, 0, {}, {})", _cameraUnitmap, (void*)bytes.data(), bytes.size()));

            if (nbytes != bytes.size()) {
                throw std::error_code(RaptorEagleCCDError::ERROR_CAMLINK_WRITE);
            }

            // send trailing ETX and possible checksum bytes
            size_t n;

            if (tr_nbytes > 1) {
                logDebug("Write trailing ETX and checksum bytes");
            } else {
                logDebug("Write trailing ETX byte");
            }
            xclibApiCall(
                n = pxd_serialWrite(_cameraUnitmap, 0, (char*)etx_checksum_bytes, tr_nbytes),
                std::format("pxd_serialWrite({}, 0, {}, {})", _cameraUnitmap, (void*)etx_checksum_bytes, tr_nbytes));
            if (n != tr_nbytes) {
                throw std::error_code(RaptorEagleCCDError::ERROR_CAMLINK_WRITE);
            }

            nbytes += n;
        }
    } else {
        logWarn("No available space in the internal Tx-buffer! Nothing to do!");
    }

    return nbytes;
}


RaptorEagleCCD::byte_seq_t RaptorEagleCCD::readRegisters(const RaptorEagleCCD::byte_seq_t& addrs,
                                                         byte_seq_t set_addr_cmd)
{
    // to protect in multi-threading environment (multiple read-write operations, see below)
    std::lock_guard lock_guard(_camlinkMutex);

    byte_seq_t reg_vals, ans(3);

    if (addrs.empty()) {
        logWarn("Registers addresses array is an empty! Nothing to do!");
        return reg_vals;
    }

    // from Eagle V 4240 instruction manual (rev 1.1)
    byte_seq_t set_addr_comm = std::move(set_addr_cmd);       // set-address controller command
    static const byte_seq_t read_reg_comm{0x53, 0xE1, 0x01};  // read-register controller command


    reg_vals.resize(addrs.size());

    size_t i = 0;
    for (auto& addr : addrs) {
        // set address
        set_addr_comm[3] = addr;
        clWrite(set_addr_comm);
        clReadAndCheckAck(ans);

        // get value
        clWrite(read_reg_comm);
        clReadAndCheckAck(ans);

        reg_vals[i++] = ans[0];
    }

    return reg_vals;
}


void RaptorEagleCCD::writeRegisters(const byte_seq_t& addrs, const byte_seq_t& values)
{
    // to protect in multi-threading environment (multiple read-write operations, see below)
    std::lock_guard lock_guard(_camlinkMutex);

    if (addrs.empty() || values.empty()) {
        logWarn("Registers addresses or values array is an empty! Nothing to do!");
        return;
    }

    size_t N = addrs.size() < values.size() ? addrs.size() : values.size();

    // from Eagle V 4240 instruction manual (rev 1.1)
    byte_seq_t comm{0x53, 0xE0, 0x02, 0x00, 0x00};

    for (size_t i = 0; i < N; ++i) {
        comm[3] = addrs[i];
        comm[4] = values[i];

        clWrite(comm);
        clReadAndCheckAck();  // no data from controller here just check answer for errors
    }
}


/*  CREATE COMMANDS AND ATTRIBUTES  */

void RaptorEagleCCD::initAttrComm()
{
    // helper to setup 8-bit register attributes
    //    'validator' is a callable with signature: std::pair<uchar, std::string> validator(const uchar&)
    auto create8BitAttr = [this](attr_ident_t name, auto reg_addr, auto&& validator, std::string_view log_mark) {
        return RaptorEagleCCD::attribute_t(
            name,
            [this, reg_addr, log_mark]() {
                auto bytes = readRegisters(reg_addr);

                logTrace("Return {} (current value: {})", log_mark, bytes[0]);

                return bytes[0];
            },
            [this, reg_addr, log_mark,
             wrapper =
                 adc::traits::adc_pf_wrapper(std::forward<decltype(validator)>(validator))](const uchar& val) mutable {
                logDebug("Try to set {} to {} ...", log_mark, val);

                // call perfectly-forwarded validator
                auto v_res = std::forward<std::tuple_element_t<0, decltype(wrapper)>>(std::get<0>(wrapper))(val);
                if (v_res.second.size()) {  // warning
                    logWarn("{}", v_res.second);
                }

                writeRegisters(reg_addr, {v_res.first});

                logDebug("{} is set to {}", log_mark, v_res.first);
            });
    };

    // helper to setup 12-bit register attributes
    //    'validator' is a callable with signature: std::pair<uint16_t, std::string> validator(const uint16_t&)
    auto create12BitAttr = [this](attr_ident_t name, auto reg_addrs, auto&& validator, std::string_view log_mark) {
        return RaptorEagleCCD::attribute_t(
            name,
            [this, reg_addrs, log_mark]() {
                auto bytes = readRegisters(reg_addrs);
                uint16_t v = details::convert12BitToUInt(bytes);

                logTrace("Return {} (current value: {})", log_mark, v);

                return v;
            },
            [this, reg_addrs, log_mark,
             wrapper = adc::traits::adc_pf_wrapper(std::forward<decltype(validator)>(validator))](
                const uint16_t& val) mutable {
                logDebug("Try to set {} to {} ...", log_mark, val);

                // call perfectly-forwarded validator
                auto v_res = std::forward<std::tuple_element_t<0, decltype(wrapper)>>(std::get<0>(wrapper))(val);
                if (v_res.second.size()) {  // warning
                    logWarn("{}", v_res.second);
                }

                auto bytes = details::convertUIntTo12Bit(v_res.first);
                writeRegisters(reg_addrs, bytes);

                logDebug("{} is set to {}", log_mark, v_res.first);
            });
    };


    /*  commands  */


    /*  attributes  */

    addAttribute(
        CAMERA_ATTR_CAMLINK_SETUP,
        [this]() {
            logTrace("Return CameraLink setup bits (current values: command-ack = {}, checksum = {})", _clCommandAckBit,
                     _clChecksumBit);

            return std::vector<uint8_t>({_clCommandAckBit, _clChecksumBit});
        },
        [this](const std::vector<uint8_t>& setup) {
            logDebug("Try to set CameraLink setup bits ...");

            if (setup.size() < 2) {
                throw std::error_code(RaptorEagleCCDError::ERROR_INVALID_ATTR_VALUE);
            }

            _clCommandAckBit = setup[0] ? 1 : 0;
            _clChecksumBit =
                (setup[1] && _clCommandAckBit) ? 1 : 0;  // checksum will be enabled only if command ack is set

            logDebug("Set CameraLink setup bits to: command-ack = {}, checksum = {}", _clCommandAckBit, _clChecksumBit);
        });


    /*  EXPOSURE AND FRAMERATE  */

    // exposure time
    addAttribute(
        CAMERA_ATTR_EXPTIME,
        [this]() {
            auto bytes = readRegisters(CL_EXPTIME_ADDR);
            size_t counts = details::convert40BitToCounts(bytes);
            double exp_time = counts * 2.5E-8;  // counts of 25nsec ticks

            logTrace("Return acquision duration (current value is {} seconds ({} 25nsec ticks))", exp_time, counts);

            return exp_time;
        },
        [this](const double& exp_time) {
            logDebug("Try to set acquisition duration to {} seconds ...", exp_time);
            double etime;

            if (exp_time < 0.0) {
                logWarn("Acquisition duration must be non-negative!");

                etime = 0.0;
            } else if (exp_time > EAGLE_CAMERA_MAX_EXPTIME) {
                logWarn("Acquisition duration must not be greater than {} seconds!", EAGLE_CAMERA_MAX_EXPTIME);

                etime = EAGLE_CAMERA_MAX_EXPTIME;
            } else {
                etime = exp_time;
            }

            size_t counts = static_cast<size_t>(std::round(etime / 2.5E-8));
            auto bytes = details::convertCountsTo40Bit(counts);
            writeRegisters(CL_EXPTIME_ADDR, bytes);

            logDebug("Acquisition duration is set to {} second ({} 25nsec ticks)", etime, counts);
        });


    // frame rate
    addAttribute(
        CAMERA_ATTR_FRAME_RATE,
        [this]() {
            auto bytes = readRegisters(CL_FRAMERATE_ADDR);
            size_t counts = details::convert40BitToCounts(bytes);

            size_t rate = counts * 40;  // in MHz

            logTrace("Return frame rate (current value is {} MHz ({} 40MHz ticks))", rate, counts);

            return rate;
        },
        [this](const size_t& rate) {
            logDebug("Try to set frame rate to {} MHz ...", rate);

            size_t r;
            if (rate < 0) {
                logWarn("Frame rate must be non-negative!");
                r = 0;
            } else if (rate > EAGLE_CAMERA_MAX_FRAMERATE) {
                logWarn("Frame rate must not be greater than {} MHz!", EAGLE_CAMERA_MAX_FRAMERATE);

                r = EAGLE_CAMERA_MAX_FRAMERATE;
            } else {
                r = rate;
            }

            size_t counts = r / 40;
            auto bytes = details::convertCountsTo40Bit(counts);
            writeRegisters(CL_FRAMERATE_ADDR, bytes);

            logDebug("Frame rate is set to {} MHz ({} 40MHz ticks)", r, counts);
        });


    // number of exposures
    addAttribute(
        CAMERA_ATTR_NEXP,
        [this]() {
            logTrace("Return number of frames in acquisition sequence (current value is {})", _frameNumbers);

            return _frameNumbers;
        },
        [this](const size_t& nframes) {
            _frameNumbers = nframes;

            logDebug("Number of frames in acquisition sequence is set to {}", _frameNumbers);
        });


    /*    FRAME GEOMETRY RELATED ATTRIBUTES   */

    // ROI left
    addAttribute(create12BitAttr(
        CAMERA_ATTR_ROI_STARTX, CL_ROI_STARTX_ADDR,
        [this]<typename T>(const T& val) {  // validator
            std::pair<T, std::string> res{val, ""};

            if (val < 1) {
                res.first = 1;
                res.second = "The ROI X-offset must start from 1 (FITS notation)";
            } else if (val > _dimCCD[0]) {
                res.first = _dimCCD[0];
                res.second = std::format(
                    "The ROI X-offset must not be greater than CCD X-dimension of {} pixels (FITS notation)",
                    _dimCCD[0]);
            }

            return res;
        },
        "ROI X-offset"));


    // ROI top
    addAttribute(create12BitAttr(
        CAMERA_ATTR_ROI_STARTY, CL_ROI_STARTY_ADDR,
        [this]<typename T>(const T& val) {  // validator
            std::pair<T, std::string> res{val, ""};

            if (val < 1) {
                res.first = 1;
                res.second = "The ROI Y-offset must start from 1 (FITS notation)";
            } else if (val > _dimCCD[1]) {
                res.first = _dimCCD[1];
                res.second = std::format(
                    "The ROI Y-offset must not be greater than CCD Y-dimension of {} pixels (FITS notation)",
                    _dimCCD[1]);
            }

            return res;
        },
        "ROI Y-offset"));


    // ROI width
    addAttribute(create12BitAttr(
        CAMERA_ATTR_ROI_WIDTH, CL_ROIWIDTH_ADDR,
        [this]<typename T>(const T& val) {  // validator
            std::pair<T, std::string> res{val, ""};

            if (val < 1) {
                res.first = 1;
                res.second = "The ROI width must start from 1";
            } else if (val > _dimCCD[0]) {
                res.first = _dimCCD[0];
                res.second = std::format(
                    "The ROI width must not be greater than CCD dimension of {} pixels (FITS notation)", _dimCCD[0]);
            }

            return res;
        },
        "ROI width"));

    // ROI height
    addAttribute(create12BitAttr(
        CAMERA_ATTR_ROI_HEIGHT, CL_ROIHEIGHT_ADDR,
        [this]<typename T>(const T& val) {  // validator
            std::pair<T, std::string> res{val, ""};

            // ROI height can be 0 (see Eagle V 4240 instruction manual)
            if (val > _dimCCD[1]) {
                res.first = _dimCCD[1];
                res.second = std::format(
                    "The ROI height must not be greater than CCD dimension of {} pixels (FITS notation)", _dimCCD[1]);
            }

            return res;
        },
        "ROI height"));

    // X-bin
    addAttribute(create8BitAttr(
        CAMERA_ATTR_XBIN, CL_XBIN_ADDR,
        []<typename T>(const T& val) {  // validator (1-32, 64)
            std::pair<T, std::string> res{val, ""};

            if (val < 1) {
                res.first = 1;
                res.second = "The XBIN must start from 1";
            } else if ((val > EAGLE_CAMERA_MAX_XBIN[0]) && (val < EAGLE_CAMERA_MAX_XBIN[1])) {
                // set to the closest
                res.first = (val - EAGLE_CAMERA_MAX_XBIN[0]) < (EAGLE_CAMERA_MAX_XBIN[1] - val)
                                ? EAGLE_CAMERA_MAX_XBIN[0]
                                : EAGLE_CAMERA_MAX_XBIN[1];

                res.second = std::format("The XBIN must not be within {} and {}", EAGLE_CAMERA_MAX_XBIN[0],
                                         EAGLE_CAMERA_MAX_XBIN[1]);
            } else if (val > EAGLE_CAMERA_MAX_XBIN[1]) {
                res.first = EAGLE_CAMERA_MAX_XBIN[1];
                res.second = std::format("The XBIN must not be greater than {}", EAGLE_CAMERA_MAX_XBIN[1]);
            }

            return res;
        },
        "XBIN"));


    // Y-bin
    addAttribute(create8BitAttr(
        CAMERA_ATTR_YBIN, CL_YBIN_ADDR,
        []<typename T>(const T& val) {  // validator (1-32, 64)
            std::pair<T, std::string> res{val, ""};

            if (val < 1) {
                res.first = 1;
                res.second = "The YBIN must start from 1";
            } else if ((val > EAGLE_CAMERA_MAX_YBIN[0]) && (val < EAGLE_CAMERA_MAX_YBIN[1])) {
                // set to the closest
                res.first = (val - EAGLE_CAMERA_MAX_YBIN[0]) < (EAGLE_CAMERA_MAX_YBIN[1] - val)
                                ? EAGLE_CAMERA_MAX_YBIN[0]
                                : EAGLE_CAMERA_MAX_YBIN[1];

                res.second = std::format("The YBIN must not be within {} and {}", EAGLE_CAMERA_MAX_YBIN[0],
                                         EAGLE_CAMERA_MAX_YBIN[1]);
            } else if (val > EAGLE_CAMERA_MAX_YBIN[1]) {
                res.first = EAGLE_CAMERA_MAX_YBIN[1];
                res.second = std::format("The YBIN must not be greater than {}", EAGLE_CAMERA_MAX_XBIN[1]);
            }

            return res;
        },
        "YBIN"));


    /*  TEC SET POINT  */

    // DAC counts
    addAttribute(create12BitAttr(
        CAMERA_ATTR_TECPOINT_DAC, CL_TECPOINT_ADDR,
        []<typename T>(const T& counts) {
            std::pair<T, std::string> res{counts, ""};

            if (counts > 0x0FFF) {
                res.second = std::format("TEC set point counts must not be greater than {}", 0x0FFF);
                res.first = 0x0FFF;
            }

            return res;
        },
        "TEC set point"));

    // floating-point value
    addAttribute(
        CAMERA_ATTR_TECPOINT,
        [this]() {
            double counts = (*this)[CAMERA_ATTR_TECPOINT_DAC];

            double k = (DAC_CALIBRATION_POINT_2 - DAC_CALIBRATION_POINT_1) /
                       (_dacTECSetPointCalibData[1] - _dacTECSetPointCalibData[0]);
            double b = _dacTECSetPointCalibData[0] - k * DAC_CALIBRATION_POINT_1;

            double temp = k * counts + b;

            logTrace("Computed Temp-to-DAC linear relation: DAC = {}*Temp + {}", k, b);

            logDebug("Return TEC set point as {} Celsius degrees", temp);

            return temp;
        },
        [this](const double& temp) {
            double k = (_dacTECSetPointCalibData[1] - _dacTECSetPointCalibData[0]) /
                       (DAC_CALIBRATION_POINT_2 - DAC_CALIBRATION_POINT_1);
            double b = DAC_CALIBRATION_POINT_1 - k * _dacTECSetPointCalibData[0];

            logTrace("Computed DAC-to-Temp linear relation: Temp = {}*DAC + {}", k, b);

            uint64_t v = static_cast<uint64_t>(temp * k + b);

            uint16_t counts = v & 0x0FFF;  // extract 12-bits

            (*this)[CAMERA_ATTR_TECPOINT_DAC] = counts;
        });


    /*  CCD and PCB temperature (read-only) */

    addAttribute(CAMERA_ATTR_PCB_TEMP, [this]() {
        uint16_t bits = 0x0FFF;
        double val = -1000;  // impossible value

        try {
            // unusual set-address command (extra 0x00 byte after the address)!
            auto bytes = readRegisters({0x70, 0x71}, {0x53, 0xE0, 0x02, 0x00, 0x00});
            bits = details::convert12BitToUInt(bytes);
            val = bits / 16.0;
        } catch (const std::system_error& ex) {
            logError("An error occured while trying to get PCB temperature! (code = {}, category = {}, msg = {})",
                     ex.code().value(), ex.code().category().name(), ex.code().message());
        }

        logTrace("Return PCB temperature (current value: {}; bits: {})", val, bits);

        return val;
    });


    addAttribute(CAMERA_ATTR_CCD_TEMP, [this]() {
        uint16_t bits = 0xFFFF;
        double val = -1000;  // impossible value

        try {
            // unusual set-address command (extra 0x00 byte after the address)!
            auto bytes = readRegisters({0x6E, 0x6F}, {0x53, 0xE0, 0x02, 0x00, 0x00});
            bits = (bytes[0] << 8) + bytes[1];

            val = _adcCCDTempCalibCoeffs[0] * bits + _adcCCDTempCalibCoeffs[1];
        } catch (const std::system_error& ex) {
            logError("An error occured while trying to get CCD temperature! (code = {}, category = {}, msg = {})",
                     ex.code().value(), ex.code().category().name(), ex.code().message());
        }

        logTrace("Return CCD temperature (current value: {}; bits: {})", val, bits);

        return val;
    });


    /*  READ-OUT MODE  (std::string_view "NORMAL" or "TEST") */

    addAttribute(
        CAMERA_ATTR_READ_MODE,
        [this]() -> std::string_view {
            auto bytes = readRegisters(CL_READMODE_ADDR);
            std::string_view val = CAMERA_ATTR_READ_MODE_NORMAL;

            if (bytes[0] == CL_READOUT_MODE_NORMAL) {
            } else if (bytes[0] == CL_READOUT_MODE_TEST) {
                val = CAMERA_ATTR_READ_MODE_TEST;
            } else {
                logError("Invalid bits in readout mode register! (reg = 0x{:02X})", bytes[0]);

                val = CAMERA_ATTR_READ_MODE_INVALID;
            }

            logTrace("Return readout mode as '{}' string", val);

            return val;
        },
        [this](const std::string_view& mode) {
            uchar bits;

            if (mode == CAMERA_ATTR_READ_MODE_NORMAL) {
                bits = CL_READOUT_MODE_NORMAL;
            }
            if (mode == CAMERA_ATTR_READ_MODE_TEST) {
                bits = CL_READOUT_MODE_TEST;
            } else {
                logWarn("Invalid '{}' string for readout mode! Use of '{}'!", mode, CAMERA_ATTR_READ_MODE_NORMAL);
                bits = CL_READOUT_MODE_NORMAL;
            }

            writeRegisters(CL_READMODE_ADDR, {bits});

            logDebug("Readout mode is set to 0x{:02X} bits", bits);
        });


    /*  READOUT RATE  (std::string_view "FAST" or "SLOW") */

    addAttribute(
        CAMERA_ATTR_READ_RATE,
        [this]() {
            auto bytes = readRegisters(CL_FRAMERATE_ADDR);
            std::string_view val;

            if ((bytes[0] == CL_READOUT_CLOCK_RATE_A3_2MHZ) && (bytes[1] == CL_READOUT_CLOCK_RATE_A4_2MHZ)) {
                val = CAMERA_ATTR_READ_RATE_FAST;
            } else if ((bytes[0] == CL_READOUT_CLOCK_RATE_A3_75KHZ) && (bytes[1] == CL_READOUT_CLOCK_RATE_A4_75KHZ)) {
                val = CAMERA_ATTR_READ_RATE_SLOW;
            } else {
                logError("Invalid bits in readout rate registers! (A3 = 0x{:02X}, A4 = 0x{:02X})", bytes[0], bytes[1]);

                val = CAMERA_ATTR_READ_RATE_INVALID;
            }

            logTrace("Return readout rate as '()' string", val);

            return val;
        },
        [this](const std::string_view& rate) {
            byte_seq_t bytes({CL_READOUT_CLOCK_RATE_A3_2MHZ, CL_READOUT_CLOCK_RATE_A4_2MHZ});
            if (rate == CAMERA_ATTR_READ_RATE_FAST) {
            } else if (rate == CAMERA_ATTR_READ_RATE_SLOW) {
                bytes[0] = CL_READOUT_CLOCK_RATE_A3_75KHZ;
                bytes[1] = CL_READOUT_CLOCK_RATE_A4_75KHZ;
            } else {
                logWarn("Invalid '{}' string for readout rate! Use of '{}'!", rate, CAMERA_ATTR_READ_RATE_FAST);
            }

            writeRegisters(CL_FRAMERATE_ADDR, bytes);

            logDebug("Readout rate is set to [0x{:02X}, 0x{:02X}] bytes", bytes[0], bytes[1]);
        });


    /*  SHUTTER CONTROL  (std::string_view "OPEN", "CLOSED", "EXP")  */

    addAttribute(
        CAMERA_ATTR_SHUTTER_STATE,
        [this]() {
            auto bytes = readRegisters(CL_SHUTTER_CONTROL_ADDR);
            std::string_view val;

            if (bytes[0] == CL_SHUTTER_CLOSED) {
                val = CAMERA_ATTR_SHUTTER_STATE_CLOSED;
            } else if (bytes[0] == CL_SHUTTER_OPEN) {
                val = CAMERA_ATTR_SHUTTER_STATE_OPEN;
            } else if (bytes[0] == CL_SHUTTER_EXP) {
                val = CAMERA_ATTR_SHUTTER_STATE_EXP;
            } else {
                logError("Invalid bits in shhutter control register! (reg = 0x{:02X})", bytes[0]);
                val = CAMERA_ATTR_SHUTTER_STATE_INVALID;
            }

            logTrace("Return shutter state as '{}' string (bits = 0x{:02X})", val, bytes[0]);

            return val;
        },
        [this](const std::string_view& state) {
            byte_seq_t bytes{CL_SHUTTER_EXP};
            if (state == CAMERA_ATTR_SHUTTER_STATE_EXP) {
            } else if (state == CAMERA_ATTR_SHUTTER_STATE_CLOSED) {
                bytes[0] = CL_SHUTTER_CLOSED;
            } else if (state == CAMERA_ATTR_SHUTTER_STATE_OPEN) {
                bytes[0] = CL_SHUTTER_OPEN;
            } else {
                logWarn("Invalid '{}' string for shutter state! Use of '{}'!", state, CL_SHUTTER_EXP);
            }

            writeRegisters(CL_SHUTTER_CONTROL_ADDR, bytes);

            logDebug("Shutter state is set to 0x{:02X}", bytes[0]);
        });
}