// STL includes
#include <cstring>
#include <cstdio>
#include <iostream>
#include <cerrno>
// Local Hyperion includes
#include "ProviderSpi.h"

#ifdef ENABLE_DEV_SPI
    // Linux includes
    #include <fcntl.h>
    #include <unistd.h>
    #include <sys/ioctl.h>
    // qt includes
    #include <QDir>
#endif

#ifdef ENABLE_DEV_FTDI
    #include <ftdi.h>
    #include <libusb.h>
    #include <utils/WaitTime.h>
    #define FTDI_CHECK_RESULT(statement) if (statement) {setInError(ftdi_get_error_string(_ftdic)); return retVal;}

    #define ANY_FTDI_VENDOR 0x0
    #define ANY_FTDI_PRODUCT 0x0


    namespace Pin
    {
        // enumerate the AD bus for convenience.
        enum bus_t
        {
            SK = 0x01, // ADBUS0, SPI data clock
            DO = 0x02, // ADBUS1, SPI data out
            CS = 0x08, // ADBUS3, SPI chip select, active low
        };
    }

    const unsigned char pinInitialState = Pin::CS;
    // Use these pins as outputs
    const unsigned char pinDirection = Pin::SK | Pin::DO | Pin::CS;
#endif


#include <utils/Logger.h>


// Constants
namespace {
	const bool verbose = false;
#ifdef ENABLE_DEV_SPI
	// SPI discovery service
	const char DISCOVERY_DIRECTORY[] = "/dev/";
	const char DISCOVERY_FILEPATTERN[] = "spidev*";
#endif

    const QString ImplementationSPIDEV = QString("spidev");
    const QString ImplementationFTDI = QString("ftdi");

} //End of constants

ProviderSpi::ProviderSpi(const QJsonObject &deviceConfig)
	: LedDevice(deviceConfig)
	, _deviceName("/dev/spidev0.0")
	, _baudRate_Hz(1000000)
#ifdef ENABLE_DEV_SPI
	, _fid(-1)
	, _spiMode(SPI_MODE_0)
	, _spiDataInvert(false)
#endif
    , _spiImplementation(SPI_SPIDEV)
{
#ifdef ENABLE_DEV_SPI
	memset(&_spi, 0, sizeof(_spi));
	_latchTime_ms = 1;
#endif
}

ProviderSpi::~ProviderSpi()
{
}

bool ProviderSpi::init(const QJsonObject &deviceConfig)
{
	bool isInitOK = false;

	// Initialise sub-class
	if ( LedDevice::init(deviceConfig) )
	{
		_deviceName    = deviceConfig["output"].toString(_deviceName);
		_baudRate_Hz   = deviceConfig["rate"].toInt(_baudRate_Hz);
#ifdef ENABLE_DEV_SPI
		_spiMode       = deviceConfig["spimode"].toInt(_spiMode);
		_spiDataInvert = deviceConfig["invert"].toBool(_spiDataInvert);
        Debug(_log, "_spiDataInvert [%d], _spiMode [%d]", _spiDataInvert, _spiMode);
#endif
        bool isFtdiImplementation = (QString::compare(deviceConfig["implementation"].toString(ImplementationSPIDEV), ImplementationFTDI, Qt::CaseInsensitive) == 0);
        _spiImplementation = isFtdiImplementation ? SPI_FTDI : SPI_SPIDEV;

		Debug(_log, "_baudRate_Hz [%d], _latchTime_ms [%d]", _baudRate_Hz, _latchTime_ms);


		isInitOK = true;
	}
	return isInitOK;
}

int ProviderSpi::open()
{
	int retVal = -1;
	QString errortext;
	_isDeviceReady = false;
if (_spiImplementation == SPI_SPIDEV) {
#ifdef ENABLE_DEV_SPI
    const int bitsPerWord = 8;

    _fid = ::open(QSTRING_CSTR(_deviceName), O_RDWR);

    if (_fid < 0)
    {
        errortext = QString ("Failed to open device (%1). Error message: %2").arg(_deviceName, strerror(errno));
        retVal = -1;
    }
    else
    {
        if (ioctl(_fid, SPI_IOC_WR_MODE, &_spiMode) == -1 || ioctl(_fid, SPI_IOC_RD_MODE, &_spiMode) == -1)
        {
            retVal = -2;
        }
        else
        {
            if (ioctl(_fid, SPI_IOC_WR_BITS_PER_WORD, &bitsPerWord) == -1 || ioctl(_fid, SPI_IOC_RD_BITS_PER_WORD, &bitsPerWord) == -1)
            {
                retVal = -4;
            }
            else
            {
                if (ioctl(_fid, SPI_IOC_WR_MAX_SPEED_HZ, &_baudRate_Hz) == -1 || ioctl(_fid, SPI_IOC_RD_MAX_SPEED_HZ, &_baudRate_Hz) == -1)
                {
                    retVal = -6;
                }
                else
                {
                    // Everything OK -> enable device
                    _isDeviceReady = true;
                    retVal = 0;
                }
            }
        }
        if ( retVal < 0 )
        {
            errortext = QString ("Failed to open device (%1). Error Code: %2").arg(_deviceName).arg(retVal);
        }
    }

    if ( retVal < 0 )
    {
        this->setInError( errortext );
    }
#endif
} else if (_spiImplementation == SPI_FTDI) {
#ifdef ENABLE_DEV_FTDI

    _ftdic = ftdi_new();

    Debug(_log, "Opening FTDI device=%s", QSTRING_CSTR(_deviceName));

    FTDI_CHECK_RESULT((retVal = ftdi_usb_open_string(_ftdic, QSTRING_CSTR(_deviceName))) < 0);
    /* doing this disable resets things if they were in a bad state */
    FTDI_CHECK_RESULT((retVal = ftdi_disable_bitbang(_ftdic)) < 0);
    FTDI_CHECK_RESULT((retVal = ftdi_setflowctrl(_ftdic, SIO_DISABLE_FLOW_CTRL)) < 0);
    FTDI_CHECK_RESULT((retVal = ftdi_set_bitmode(_ftdic, 0x00, BITMODE_RESET)) < 0);
    FTDI_CHECK_RESULT((retVal = ftdi_set_bitmode(_ftdic, 0xff, BITMODE_MPSSE)) < 0);


    double reference_clock = 60e6;
    int divisor = (reference_clock / 2 / _baudRate_Hz) - 1;
    std::vector<uint8_t> buf = {
            DIS_DIV_5,
            TCK_DIVISOR,
            static_cast<unsigned char>(divisor),
            static_cast<unsigned char>(divisor >> 8),
            SET_BITS_LOW,		  // opcode: set low bits (ADBUS[0-7]
            pinInitialState,    // argument: inital pin state
            pinDirection
    };

    FTDI_CHECK_RESULT((retVal = ftdi_write_data(_ftdic, buf.data(), buf.size())) != buf.size());

    _isDeviceReady = true;
#endif
}
	return retVal;
}

int ProviderSpi::close()
{
	// LedDevice specific closing activities
	int retVal = 0;
	_isDeviceReady = false;
    if (_spiImplementation == SPI_SPIDEV) {
#ifdef ENABLE_DEV_SPI
        // Test, if device requires closing
        if ( _fid > -1 )
        {
            // Close device
            if ( ::close(_fid) != 0 )
            {
                Error( _log, "Failed to close device (%s). Error message: %s", QSTRING_CSTR(_deviceName),  strerror(errno) );
                retVal = -1;
            }
        }
#endif
    } else if (_spiImplementation == SPI_FTDI) {
#ifdef ENABLE_DEV_FTDI
    if (_ftdic != nullptr) {
            Debug(_log, "Closing FTDI device");
    //      Delay to give time to push color black from writeBlack() into the led,
    //      otherwise frame transmission will be terminated half way through
            wait(30);
            ftdi_set_bitmode(_ftdic, 0x00, BITMODE_RESET);
            ftdi_usb_close(_ftdic);
            ftdi_free(_ftdic);
            _ftdic = nullptr;
        }
#endif
    }
	return retVal;
}

int ProviderSpi::writeBytes(unsigned size, const uint8_t * data)
{
    int retVal = 0;
    if (_spiImplementation == SPI_SPIDEV) {
#ifdef ENABLE_DEV_SPI
        if (_fid < 0)
        {
            return -1;
        }

        uint8_t * newdata {nullptr};

        _spi.tx_buf = __u64(data);
        _spi.len    = __u32(size);

        if (_spiDataInvert)
        {
            newdata = static_cast<uint8_t *>(malloc(size));
            for (unsigned i = 0; i<size; i++) {
                newdata[i] = data[i] ^ 0xff;
            }
            _spi.tx_buf = __u64(newdata);
        }

        retVal = ioctl(_fid, SPI_IOC_MESSAGE(1), &_spi);
        ErrorIf((retVal < 0), _log, "SPI failed to write. errno: %d, %s", errno,  strerror(errno) );

        free (newdata);
#endif
    } else if (_spiImplementation == SPI_FTDI) {
#ifdef ENABLE_DEV_FTDI
        int count_arg = size - 1;
        std::vector<uint8_t> buf = {
                SET_BITS_LOW,
                pinInitialState & ~Pin::CS,
                pinDirection,
                MPSSE_DO_WRITE | MPSSE_WRITE_NEG,
                static_cast<unsigned char>(count_arg),
                static_cast<unsigned char>(count_arg >> 8),
//            LED's data will be inserted here
                SET_BITS_LOW,
                pinInitialState | Pin::CS,
                pinDirection
        };
        // insert before last SET_BITS_LOW command
        // SET_BITS_LOW takes 2 arguments, so we're inserting data in -3 position from the end
        buf.insert(buf.end() - 3, &data[0], &data[size]);

        FTDI_CHECK_RESULT((retVal = ftdi_write_data(_ftdic, buf.data(), buf.size())) != buf.size());
#endif
    }
	return retVal;
}

QJsonObject ProviderSpi::discover(const QJsonObject& /*params*/)
{
	QJsonObject devicesDiscovered;
	devicesDiscovered.insert("ledDeviceType", _activeDeviceType );
	QJsonArray deviceList;

#ifdef ENABLE_DEV_SPI
	QDir deviceDirectory (DISCOVERY_DIRECTORY);
	QStringList deviceFilter(DISCOVERY_FILEPATTERN);
	deviceDirectory.setNameFilters(deviceFilter);
	deviceDirectory.setSorting(QDir::Name);
	QFileInfoList deviceFiles = deviceDirectory.entryInfoList(QDir::System);

	QFileInfoList::const_iterator deviceFileIterator;
	for (deviceFileIterator = deviceFiles.constBegin(); deviceFileIterator != deviceFiles.constEnd(); ++deviceFileIterator)
	{
		QJsonObject deviceInfo;
		deviceInfo.insert("deviceName", (*deviceFileIterator).fileName().remove(0,6));
		deviceInfo.insert("systemLocation", (*deviceFileIterator).absoluteFilePath());
		deviceInfo.insert("implementation", ImplementationSPIDEV);
		deviceList.append(deviceInfo);
	}
#endif
#ifdef ENABLE_DEV_FTDI
        struct ftdi_device_list *devlist;
        struct ftdi_context *ftdic;

        ftdic = ftdi_new();

        if (ftdi_usb_find_all(ftdic, &devlist, ANY_FTDI_VENDOR, ANY_FTDI_PRODUCT) > 0)
        {
            struct ftdi_device_list *curdev = devlist;
            QMap<QString, uint8_t> deviceIndexes;

            while (curdev)
            {
                libusb_device_descriptor desc;
                int rc = libusb_get_device_descriptor(curdev->dev, &desc);
                if (rc == 0)
                {
                    QString vendorIdentifier =  QString("0x%1").arg(desc.idVendor, 4, 16, QChar{'0'});
                    QString productIdentifier = QString("0x%1").arg(desc.idProduct, 4, 16, QChar{'0'});
                    QString vendorAndProduct = QString("%1:%2")
                            .arg(vendorIdentifier)
                            .arg(productIdentifier);
                    uint8_t deviceIndex = deviceIndexes.value(vendorAndProduct, 0);

                    char serial_string[128] = {0};
                    char manufacturer_string[128] = {0};
                    char description_string[128] = {0};
                    ftdi_usb_get_strings2(ftdic, curdev->dev, manufacturer_string, 128, description_string, 128, serial_string, 128);

                    QString serialNumber {serial_string};
                    QString ftdiOpenString;
                    if(!serialNumber.isEmpty())
                    {
                        ftdiOpenString = QString("s:%1:%2").arg(vendorAndProduct).arg(serialNumber);
                    }
                    else
                    {
                        ftdiOpenString = QString("i:%1:%2").arg(vendorAndProduct).arg(deviceIndex);
                    }

                    deviceList.push_back(QJsonObject{
                            {"ftdiOpenString", ftdiOpenString},
                            {"vendorIdentifier", vendorIdentifier},
                            {"productIdentifier", productIdentifier},
                            {"deviceIndex", deviceIndex},
                            {"serialNumber", serialNumber},
                            {"manufacturer", manufacturer_string},
                            {"description", description_string},
                            {"deviceName", description_string},
                            {"systemLocation", ftdiOpenString},
                            {"implementation", ImplementationFTDI},
                    });
                    deviceIndexes.insert(vendorAndProduct, deviceIndex + 1);
                }
                curdev = curdev->next;
            }
        }

        ftdi_list_free(&devlist);
        ftdi_free(ftdic);
#endif
    devicesDiscovered.insert("devices", deviceList);
	DebugIf(verbose,_log, "devicesDiscovered: [%s]", QString(QJsonDocument(devicesDiscovered).toJson(QJsonDocument::Compact)).toUtf8().constData());

	return devicesDiscovered;
}