/**
* @file VL6180_ATY.c
*
* @param Project DEVICE_GENERAL_ATY_LIB
*
* @author ATY
*
* @copyright
*       - Copyright 2017 - 2026 MZ-ATY
*       - This code follows:
*           - MZ-ATY Various Contents Joint Statement -
*               <a href="https://mengze.top/MZ-ATY_VCJS">
*                        https://mengze.top/MZ-ATY_VCJS</a>
*           - CC 4.0 BY-NC-SA -
*               <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">
*                        https://creativecommons.org/licenses/by-nc-sa/4.0/</a>
*       - Your use will be deemed to have accepted the terms of this statement.
*
* @brief functions of VL6180 proximity and ambient light sensor for all embedded device
*
* @version
*       - 1_00_250101 > ATY
*           -# Initial version, support I2C communication, range and ALS measurement
********************************************************************************
*/

#include "VL6180_ATY.h"

/******************************* Private Functions *****************************/

/**
 * @brief Check if device is initialized, auto-initialize if not
 * @param dev Pointer to VL6180 device structure
 * @return VL6180_STATUS_OK if successful
 */
static uint8_t VL6180_CheckAndAutoInit(struct VL6180_ATY_Dev *dev)
{
    if (!dev->initialized) {
        if (dev->debugEnable && dev->LOG) {
            dev->LOG("VL6180: Auto-initializing device...\n");
        }
        return VL6180_Init(dev);
    }
    return VL6180_STATUS_OK;
}

/**
 * @brief VL6180 default initialization settings
 * @param dev Pointer to VL6180 device structure
 * @return VL6180_STATUS_OK if successful
 */
static uint8_t VL6180_ApplyDefaultSettings(struct VL6180_ATY_Dev *dev)
{
    // Mandatory: Private registers
    VL6180_WriteRegister8(dev, 0x0207, 0x01);
    VL6180_WriteRegister8(dev, 0x0208, 0x01);
    VL6180_WriteRegister8(dev, 0x0096, 0x00);
    VL6180_WriteRegister8(dev, 0x0097, 0xfd);
    VL6180_WriteRegister8(dev, 0x00e3, 0x00);
    VL6180_WriteRegister8(dev, 0x00e4, 0x04);
    VL6180_WriteRegister8(dev, 0x00e5, 0x02);
    VL6180_WriteRegister8(dev, 0x00e6, 0x01);
    VL6180_WriteRegister8(dev, 0x00e7, 0x03);
    VL6180_WriteRegister8(dev, 0x00f5, 0x02);
    VL6180_WriteRegister8(dev, 0x00d9, 0x05);
    VL6180_WriteRegister8(dev, 0x00db, 0xce);
    VL6180_WriteRegister8(dev, 0x00dc, 0x03);
    VL6180_WriteRegister8(dev, 0x00dd, 0xf8);
    VL6180_WriteRegister8(dev, 0x009f, 0x00);
    VL6180_WriteRegister8(dev, 0x00a3, 0x3c);
    VL6180_WriteRegister8(dev, 0x00b7, 0x00);
    VL6180_WriteRegister8(dev, 0x00bb, 0x3c);
    VL6180_WriteRegister8(dev, 0x00b2, 0x09);
    VL6180_WriteRegister8(dev, 0x00ca, 0x09);
    VL6180_WriteRegister8(dev, 0x0198, 0x01);
    VL6180_WriteRegister8(dev, 0x01b0, 0x17);
    VL6180_WriteRegister8(dev, 0x01ad, 0x00);
    VL6180_WriteRegister8(dev, 0x00ff, 0x05);
    VL6180_WriteRegister8(dev, 0x0100, 0x05);
    VL6180_WriteRegister8(dev, 0x0199, 0x05);
    VL6180_WriteRegister8(dev, 0x01a6, 0x1b);
    VL6180_WriteRegister8(dev, 0x01ac, 0x3e);
    VL6180_WriteRegister8(dev, 0x01a7, 0x1f);
    VL6180_WriteRegister8(dev, 0x0030, 0x00);

    // Recommended: Public registers - See data sheet for more detail
    VL6180_WriteRegister8(dev, VL6180_REG_SYSTEM_MODE_GPIO1, 0x10); // Enables polling for 'New Sample ready'
    VL6180_WriteRegister8(dev, VL6180_REG_READOUT_AVERAGING_SAMPLE_PERIOD, 0x30); // Set the averaging sample period
    VL6180_WriteRegister8(dev, VL6180_REG_SYSALS_ANALOGUE_GAIN, 0x46); // Light sensor gain settings
    VL6180_WriteRegister8(dev, VL6180_REG_SYSRANGE_VHV_REPEAT_RATE, 0xFF); // Set auto calibration period
    VL6180_WriteRegister8(dev, VL6180_REG_SYSALS_INTEGRATION_PERIOD, 0x63); // ALS integration time
    VL6180_WriteRegister8(dev, VL6180_REG_SYSRANGE_VHV_RECALIBRATE, 0x01); // perform a single temperature calibration
    VL6180_WriteRegister8(dev, VL6180_REG_SYSRANGE_INTERMEASUREMENT_PERIOD, 0x09); // Set default ranging inter-measurement period to 100ms
    VL6180_WriteRegister8(dev, VL6180_REG_SYSALS_INTERMEASUREMENT_PERIOD, 0x31); // Set default ALS inter-measurement period to 500ms
    VL6180_WriteRegister8(dev, VL6180_REG_SYSTEM_INTERRUPT_CONFIG_GPIO, 0x24); // Configures interrupt on 'New Sample Ready threshold event'

    // Clear fresh out of reset flag
    VL6180_WriteRegister8(dev, VL6180_REG_SYSTEM_FRESH_OUT_OF_RESET, 0x00);

    return VL6180_STATUS_OK;
}

/******************************* Public Functions *****************************/

/**
 * @brief Initialize VL6180 device
 * @param dev Pointer to VL6180 device structure
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_Init(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    if (dev->debugEnable && dev->LOG) {
        dev->LOG("VL6180: Initializing device...\n");
    }

    // Set default I2C address if not set
    if (dev->i2cAddress == 0) {
        dev->i2cAddress = VL6180_I2C_ADDR_DEFAULT;
    }

    // Check if device is present
    uint8_t modelId;
    if (VL6180_ReadRegister8(dev, VL6180_REG_IDENTIFICATION_MODEL_ID, &modelId) != VL6180_STATUS_OK) {
        dev->devicePresent = 0;
        dev->lastStatus = VL6180_STATUS_NO_DEVICE;
        if (dev->debugEnable && dev->LOG) {
            dev->LOG("VL6180: Device not found!\n");
        }
        return VL6180_STATUS_NO_DEVICE;
    }

    if (modelId != 0xB4) {
        dev->devicePresent = 0;
        dev->lastStatus = VL6180_STATUS_NO_DEVICE;
        if (dev->debugEnable && dev->LOG) {
            dev->LOG("VL6180: Invalid model ID: 0x%02X\n", modelId);
        }
        return VL6180_STATUS_NO_DEVICE;
    }

    dev->devicePresent = 1;
    dev->modelId = modelId;

    // Read device identification
    VL6180_ReadDeviceID(dev);

    // Check if fresh out of reset
    uint8_t freshOutOfReset;
    VL6180_ReadRegister8(dev, VL6180_REG_SYSTEM_FRESH_OUT_OF_RESET, &freshOutOfReset);
    dev->freshOutOfReset = freshOutOfReset;

    if (freshOutOfReset == 0x01) {
        // Apply default settings
        VL6180_ApplyDefaultSettings(dev);
        if (dev->debugEnable && dev->LOG) {
            dev->LOG("VL6180: Applied default settings\n");
        }
    }

    // Set default configuration
    dev->alsGain = VL6180_ALS_GAIN_1;
    dev->alsIntegrationPeriod = 100;
    dev->rangeMaxConvergenceTime = 50;
    dev->rangeOffset = 0;
    dev->crosstalkCompensationRate = 0;

    dev->initialized = 1;
    dev->lastStatus = VL6180_STATUS_OK;

    if (dev->debugEnable && dev->LOG) {
        dev->LOG("VL6180: Initialization completed successfully\n");
    }

    return VL6180_STATUS_OK;
}

/**
 * @brief Reset VL6180 device
 * @param dev Pointer to VL6180 device structure
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_Reset(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    if (dev->debugEnable && dev->LOG) {
        dev->LOG("VL6180: Resetting device...\n");
    }

    // Clear all interrupt flags
    VL6180_WriteRegister8(dev, VL6180_REG_SYSTEM_INTERRUPT_CLEAR, 0x07);

    // Reset device state
    dev->initialized = 0;
    dev->devicePresent = 0;
    dev->rangeValue = 0;
    dev->alsValue = 0;
    dev->rangeStatus = 0;
    dev->alsStatus = 0;

    dev->lastStatus = VL6180_STATUS_OK;
    return VL6180_STATUS_OK;
}

/**
 * @brief Read device identification information
 * @param dev Pointer to VL6180 device structure
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_ReadDeviceID(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    VL6180_ReadRegister8(dev, VL6180_REG_IDENTIFICATION_MODEL_ID, &dev->modelId);
    VL6180_ReadRegister8(dev, VL6180_REG_IDENTIFICATION_MODEL_REV_MAJOR, &dev->modelRevMajor);
    VL6180_ReadRegister8(dev, VL6180_REG_IDENTIFICATION_MODEL_REV_MINOR, &dev->modelRevMinor);
    VL6180_ReadRegister8(dev, VL6180_REG_IDENTIFICATION_MODULE_REV_MAJOR, &dev->moduleRevMajor);
    VL6180_ReadRegister8(dev, VL6180_REG_IDENTIFICATION_MODULE_REV_MINOR, &dev->moduleRevMinor);

    if (dev->debugEnable && dev->LOG) {
        dev->LOG("VL6180: Model ID: 0x%02X, Rev: %d.%d, Module Rev: %d.%d\n",
                dev->modelId, dev->modelRevMajor, dev->modelRevMinor,
                dev->moduleRevMajor, dev->moduleRevMinor);
    }

    return VL6180_STATUS_OK;
}

/**
 * @brief Load default settings to VL6180
 * @param dev Pointer to VL6180 device structure
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_LoadDefaultSettings(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    return VL6180_ApplyDefaultSettings(dev);
}

/******************************* Range Measurement Functions *****************/

/**
 * @brief Start range measurement
 * @param dev Pointer to VL6180 device structure
 * @param mode Measurement mode (single shot or continuous)
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_StartRangeMeasurement(struct VL6180_ATY_Dev *dev, uint8_t mode)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    // Auto-initialize if not initialized
    uint8_t status = VL6180_CheckAndAutoInit(dev);
    if (status != VL6180_STATUS_OK) {
        return status;
    }

    if (dev->lock) {
        if (dev->debugEnable && dev->LOG) {
            dev->LOG("VL6180: Device is locked\n");
        }
        return VL6180_STATUS_ERROR;
    }

    dev->lock = 1;

    if (dev->debugEnable && dev->LOG) {
        dev->LOG("VL6180: Starting range measurement (mode: %d)\n", mode);
    }

    // Clear any existing interrupts
    VL6180_ClearRangeInterrupt(dev);

    // Start measurement
    status = VL6180_WriteRegister8(dev, VL6180_REG_SYSRANGE_START, mode);

    dev->lock = 0;
    dev->lastStatus = status;
    return status;
}

/**
 * @brief Read range measurement result
 * @param dev Pointer to VL6180 device structure
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_ReadRangeResult(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    // Auto-initialize if not initialized
    uint8_t status = VL6180_CheckAndAutoInit(dev);
    if (status != VL6180_STATUS_OK) {
        return status;
    }

    if (dev->lock) {
        return VL6180_STATUS_ERROR;
    }

    dev->lock = 1;

    // Read range value
    VL6180_ReadRegister8(dev, VL6180_REG_RESULT_RANGE_VAL, &dev->rangeValue);

    // Read range status
    VL6180_ReadRegister8(dev, VL6180_REG_RESULT_RANGE_STATUS, &dev->rangeStatus);

    // Read additional range data
    VL6180_ReadRegister16(dev, VL6180_REG_RESULT_RANGE_RAW, &dev->rangeRaw);
    VL6180_ReadRegister16(dev, VL6180_REG_RESULT_RANGE_RETURN_RATE, &dev->rangeRate);
    VL6180_ReadRegister32(dev, VL6180_REG_RESULT_RANGE_RETURN_SIGNAL_COUNT, &dev->rangeSignalCount);
    VL6180_ReadRegister32(dev, VL6180_REG_RESULT_RANGE_RETURN_AMB_COUNT, &dev->rangeAmbientCount);
    VL6180_ReadRegister16(dev, VL6180_REG_RESULT_RANGE_RETURN_CONV_TIME, &dev->rangeConvergenceTime);

    if (dev->debugEnable && dev->LOG) {
        dev->LOG("VL6180: Range: %dmm, Status: 0x%02X, Rate: %d\n",
                dev->rangeValue, dev->rangeStatus, dev->rangeRate);
    }

    dev->lock = 0;
    dev->lastStatus = VL6180_STATUS_OK;
    return VL6180_STATUS_OK;
}

/**
 * @brief Get range measurement value
 * @param dev Pointer to VL6180 device structure
 * @return Range value in millimeters
 */
uint8_t VL6180_GetRangeValue(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return 0;
    }
    return dev->rangeValue;
}

/**
 * @brief Check if range measurement is ready
 * @param dev Pointer to VL6180 device structure
 * @return 1 if ready, 0 if not ready
 */
uint8_t VL6180_IsRangeReady(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return 0;
    }

    uint8_t status;
    VL6180_ReadRegister8(dev, VL6180_REG_RESULT_INTERRUPT_STATUS_GPIO, &status);
    return (status & 0x04) ? 1 : 0;
}

/**
 * @brief Clear range interrupt
 * @param dev Pointer to VL6180 device structure
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_ClearRangeInterrupt(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    return VL6180_WriteRegister8(dev, VL6180_REG_SYSTEM_INTERRUPT_CLEAR, 0x01);
}

/******************************* ALS Measurement Functions *******************/

/**
 * @brief Start ALS measurement
 * @param dev Pointer to VL6180 device structure
 * @param mode Measurement mode (single shot or continuous)
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_StartALSMeasurement(struct VL6180_ATY_Dev *dev, uint8_t mode)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    // Auto-initialize if not initialized
    uint8_t status = VL6180_CheckAndAutoInit(dev);
    if (status != VL6180_STATUS_OK) {
        return status;
    }

    if (dev->lock) {
        if (dev->debugEnable && dev->LOG) {
            dev->LOG("VL6180: Device is locked\n");
        }
        return VL6180_STATUS_ERROR;
    }

    dev->lock = 1;

    if (dev->debugEnable && dev->LOG) {
        dev->LOG("VL6180: Starting ALS measurement (mode: %d)\n", mode);
    }

    // Clear any existing interrupts
    VL6180_ClearALSInterrupt(dev);

    // Start measurement
    status = VL6180_WriteRegister8(dev, VL6180_REG_SYSALS_START, mode);

    dev->lock = 0;
    dev->lastStatus = status;
    return status;
}

/**
 * @brief Read ALS measurement result
 * @param dev Pointer to VL6180 device structure
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_ReadALSResult(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    // Auto-initialize if not initialized
    uint8_t status = VL6180_CheckAndAutoInit(dev);
    if (status != VL6180_STATUS_OK) {
        return status;
    }

    if (dev->lock) {
        return VL6180_STATUS_ERROR;
    }

    dev->lock = 1;

    // Read ALS value
    VL6180_ReadRegister16(dev, VL6180_REG_RESULT_ALS_VAL, &dev->alsValue);

    // Read ALS status
    VL6180_ReadRegister8(dev, VL6180_REG_RESULT_ALS_STATUS, &dev->alsStatus);

    if (dev->debugEnable && dev->LOG) {
        dev->LOG("VL6180: ALS: %d counts, Status: 0x%02X\n",
                dev->alsValue, dev->alsStatus);
    }

    dev->lock = 0;
    dev->lastStatus = VL6180_STATUS_OK;
    return VL6180_STATUS_OK;
}

/**
 * @brief Get ALS measurement value
 * @param dev Pointer to VL6180 device structure
 * @return ALS value in counts
 */
uint16_t VL6180_GetALSValue(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return 0;
    }
    return dev->alsValue;
}

/**
 * @brief Check if ALS measurement is ready
 * @param dev Pointer to VL6180 device structure
 * @return 1 if ready, 0 if not ready
 */
uint8_t VL6180_IsALSReady(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return 0;
    }

    uint8_t status;
    VL6180_ReadRegister8(dev, VL6180_REG_RESULT_INTERRUPT_STATUS_GPIO, &status);
    return (status & 0x20) ? 1 : 0;
}

/**
 * @brief Clear ALS interrupt
 * @param dev Pointer to VL6180 device structure
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_ClearALSInterrupt(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    return VL6180_WriteRegister8(dev, VL6180_REG_SYSTEM_INTERRUPT_CLEAR, 0x02);
}

/******************************* Configuration Functions *********************/

/**
 * @brief Set range measurement thresholds
 * @param dev Pointer to VL6180 device structure
 * @param low Low threshold in mm
 * @param high High threshold in mm
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_SetRangeThresholds(struct VL6180_ATY_Dev *dev, uint8_t low, uint8_t high)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    dev->rangeThresholdLow = low;
    dev->rangeThresholdHigh = high;

    VL6180_WriteRegister8(dev, VL6180_REG_SYSRANGE_THRESH_LOW, low);
    VL6180_WriteRegister8(dev, VL6180_REG_SYSRANGE_THRESH_HIGH, high);

    return VL6180_STATUS_OK;
}

/**
 * @brief Set ALS measurement thresholds
 * @param dev Pointer to VL6180 device structure
 * @param low Low threshold in counts
 * @param high High threshold in counts
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_SetALSThresholds(struct VL6180_ATY_Dev *dev, uint16_t low, uint16_t high)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    dev->alsThresholdLow = low;
    dev->alsThresholdHigh = high;

    VL6180_WriteRegister16(dev, VL6180_REG_SYSALS_THRESH_LOW, low);
    VL6180_WriteRegister16(dev, VL6180_REG_SYSALS_THRESH_HIGH, high);

    return VL6180_STATUS_OK;
}

/**
 * @brief Set ALS gain
 * @param dev Pointer to VL6180 device structure
 * @param gain ALS gain setting
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_SetALSGain(struct VL6180_ATY_Dev *dev, uint8_t gain)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    if (gain > VL6180_ALS_GAIN_40) {
        return VL6180_STATUS_ERROR;
    }

    dev->alsGain = gain;
    return VL6180_WriteRegister8(dev, VL6180_REG_SYSALS_ANALOGUE_GAIN, (0x40 | gain));
}

/**
 * @brief Set ALS integration period
 * @param dev Pointer to VL6180 device structure
 * @param period Integration period in ms (1-512ms)
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_SetALSIntegrationPeriod(struct VL6180_ATY_Dev *dev, uint16_t period)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    if (period < 1 || period > 512) {
        return VL6180_STATUS_ERROR;
    }

    dev->alsIntegrationPeriod = period;
    return VL6180_WriteRegister16(dev, VL6180_REG_SYSALS_INTEGRATION_PERIOD, period - 1);
}

/**
 * @brief Set range offset calibration
 * @param dev Pointer to VL6180 device structure
 * @param offset Offset value in mm (-128 to +127)
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_SetRangeOffset(struct VL6180_ATY_Dev *dev, int8_t offset)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    dev->rangeOffset = offset;
    return VL6180_WriteRegister8(dev, VL6180_REG_SYSRANGE_PART_TO_PART_RANGE_OFFSET, (uint8_t)offset);
}

/**
 * @brief Set crosstalk compensation
 * @param dev Pointer to VL6180 device structure
 * @param rate Crosstalk compensation rate
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_SetCrosstalkCompensation(struct VL6180_ATY_Dev *dev, uint16_t rate)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }

    dev->crosstalkCompensationRate = rate;
    return VL6180_WriteRegister16(dev, VL6180_REG_SYSRANGE_CROSSTALK_COMPENSATION_RATE, rate);
}

/******************************* I2C Register Access Functions ***************/

/**
 * @brief Write 8-bit register
 * @param dev Pointer to VL6180 device structure
 * @param reg Register address
 * @param data Data to write
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_WriteRegister8(struct VL6180_ATY_Dev *dev, uint16_t reg, uint8_t data)
{
    if (!dev || !dev->i2cStart || !dev->i2cStop || !dev->i2cWriteByte) {
        return VL6180_STATUS_ERROR;
    }

    // Start I2C transaction
    if (dev->i2cStart() != 0) {
        return VL6180_STATUS_ERROR;
    }

    // Send device address with write bit
    if (dev->i2cWriteByte((dev->i2cAddress << 1) | 0x00) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send register address (16-bit, MSB first)
    if (dev->i2cWriteByte((reg >> 8) & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    if (dev->i2cWriteByte(reg & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send data
    if (dev->i2cWriteByte(data) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Stop I2C transaction
    dev->i2cStop();

    return VL6180_STATUS_OK;
}

/**
 * @brief Write 16-bit register
 * @param dev Pointer to VL6180 device structure
 * @param reg Register address
 * @param data Data to write
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_WriteRegister16(struct VL6180_ATY_Dev *dev, uint16_t reg, uint16_t data)
{
    if (!dev || !dev->i2cStart || !dev->i2cStop || !dev->i2cWriteByte) {
        return VL6180_STATUS_ERROR;
    }

    // Start I2C transaction
    if (dev->i2cStart() != 0) {
        return VL6180_STATUS_ERROR;
    }

    // Send device address with write bit
    if (dev->i2cWriteByte((dev->i2cAddress << 1) | 0x00) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send register address (16-bit, MSB first)
    if (dev->i2cWriteByte((reg >> 8) & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    if (dev->i2cWriteByte(reg & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send data (16-bit, MSB first)
    if (dev->i2cWriteByte((data >> 8) & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    if (dev->i2cWriteByte(data & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Stop I2C transaction
    dev->i2cStop();

    return VL6180_STATUS_OK;
}

/**
 * @brief Write 32-bit register
 * @param dev Pointer to VL6180 device structure
 * @param reg Register address
 * @param data Data to write
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_WriteRegister32(struct VL6180_ATY_Dev *dev, uint16_t reg, uint32_t data)
{
    if (!dev || !dev->i2cStart || !dev->i2cStop || !dev->i2cWriteByte) {
        return VL6180_STATUS_ERROR;
    }

    // Start I2C transaction
    if (dev->i2cStart() != 0) {
        return VL6180_STATUS_ERROR;
    }

    // Send device address with write bit
    if (dev->i2cWriteByte((dev->i2cAddress << 1) | 0x00) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send register address (16-bit, MSB first)
    if (dev->i2cWriteByte((reg >> 8) & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    if (dev->i2cWriteByte(reg & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send data (32-bit, MSB first)
    if (dev->i2cWriteByte((data >> 24) & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    if (dev->i2cWriteByte((data >> 16) & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    if (dev->i2cWriteByte((data >> 8) & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    if (dev->i2cWriteByte(data & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Stop I2C transaction
    dev->i2cStop();

    return VL6180_STATUS_OK;
}

/**
 * @brief Read 8-bit register
 * @param dev Pointer to VL6180 device structure
 * @param reg Register address
 * @param data Pointer to store read data
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_ReadRegister8(struct VL6180_ATY_Dev *dev, uint16_t reg, uint8_t *data)
{
    if (!dev || !data || !dev->i2cStart || !dev->i2cStop || !dev->i2cWriteByte || !dev->i2cReadByte) {
        return VL6180_STATUS_ERROR;
    }

    // Start I2C transaction for write
    if (dev->i2cStart() != 0) {
        return VL6180_STATUS_ERROR;
    }

    // Send device address with write bit
    if (dev->i2cWriteByte((dev->i2cAddress << 1) | 0x00) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send register address (16-bit, MSB first)
    if (dev->i2cWriteByte((reg >> 8) & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    if (dev->i2cWriteByte(reg & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Restart for read
    if (dev->i2cStart() != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send device address with read bit
    if (dev->i2cWriteByte((dev->i2cAddress << 1) | 0x01) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Read data
    *data = dev->i2cReadByte(0); // NACK for last byte

    // Stop I2C transaction
    dev->i2cStop();

    return VL6180_STATUS_OK;
}

/**
 * @brief Read 16-bit register
 * @param dev Pointer to VL6180 device structure
 * @param reg Register address
 * @param data Pointer to store read data
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_ReadRegister16(struct VL6180_ATY_Dev *dev, uint16_t reg, uint16_t *data)
{
    if (!dev || !data || !dev->i2cStart || !dev->i2cStop || !dev->i2cWriteByte || !dev->i2cReadByte) {
        return VL6180_STATUS_ERROR;
    }

    // Start I2C transaction for write
    if (dev->i2cStart() != 0) {
        return VL6180_STATUS_ERROR;
    }

    // Send device address with write bit
    if (dev->i2cWriteByte((dev->i2cAddress << 1) | 0x00) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send register address (16-bit, MSB first)
    if (dev->i2cWriteByte((reg >> 8) & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    if (dev->i2cWriteByte(reg & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Restart for read
    if (dev->i2cStart() != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send device address with read bit
    if (dev->i2cWriteByte((dev->i2cAddress << 1) | 0x01) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Read data (16-bit, MSB first)
    uint8_t msb = dev->i2cReadByte(1); // ACK for first byte
    uint8_t lsb = dev->i2cReadByte(0); // NACK for last byte

    *data = (msb << 8) | lsb;

    // Stop I2C transaction
    dev->i2cStop();

    return VL6180_STATUS_OK;
}

/**
 * @brief Read 32-bit register
 * @param dev Pointer to VL6180 device structure
 * @param reg Register address
 * @param data Pointer to store read data
 * @return VL6180_STATUS_OK if successful
 */
uint8_t VL6180_ReadRegister32(struct VL6180_ATY_Dev *dev, uint16_t reg, uint32_t *data)
{
    if (!dev || !data || !dev->i2cStart || !dev->i2cStop || !dev->i2cWriteByte || !dev->i2cReadByte) {
        return VL6180_STATUS_ERROR;
    }

    // Start I2C transaction for write
    if (dev->i2cStart() != 0) {
        return VL6180_STATUS_ERROR;
    }

    // Send device address with write bit
    if (dev->i2cWriteByte((dev->i2cAddress << 1) | 0x00) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send register address (16-bit, MSB first)
    if (dev->i2cWriteByte((reg >> 8) & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    if (dev->i2cWriteByte(reg & 0xFF) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Restart for read
    if (dev->i2cStart() != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Send device address with read bit
    if (dev->i2cWriteByte((dev->i2cAddress << 1) | 0x01) != 0) {
        dev->i2cStop();
        return VL6180_STATUS_ERROR;
    }

    // Read data (32-bit, MSB first)
    uint8_t byte3 = dev->i2cReadByte(1); // ACK
    uint8_t byte2 = dev->i2cReadByte(1); // ACK
    uint8_t byte1 = dev->i2cReadByte(1); // ACK
    uint8_t byte0 = dev->i2cReadByte(0); // NACK for last byte

    *data = (byte3 << 24) | (byte2 << 16) | (byte1 << 8) | byte0;

    // Stop I2C transaction
    dev->i2cStop();

    return VL6180_STATUS_OK;
}

/******************************* Utility Functions ***************************/

/**
 * @brief Get device status
 * @param dev Pointer to VL6180 device structure
 * @return Device status
 */
uint8_t VL6180_GetDeviceStatus(struct VL6180_ATY_Dev *dev)
{
    if (!dev) {
        return VL6180_STATUS_ERROR;
    }
    return dev->lastStatus;
}

/**
 * @brief Set I2C address
 * @param dev Pointer to VL6180 device structure
 * @param address New I2C address
 */
void VL6180_SetI2CAddress(struct VL6180_ATY_Dev *dev, uint8_t address)
{
    if (dev) {
        dev->i2cAddress = address;
    }
}

/**
 * @brief Convert ALS counts to lux
 * @param dev Pointer to VL6180 device structure
 * @param alsValue ALS value in counts
 * @return Lux value
 */
float VL6180_ConvertALSToLux(struct VL6180_ATY_Dev *dev, uint16_t alsValue)
{
    if (!dev) {
        return 0.0f;
    }

    // Gain factors for different ALS gain settings
    float gainFactors[] = {20.0f, 10.32f, 5.21f, 2.60f, 1.72f, 1.28f, 1.01f, 40.0f};
    
    if (dev->alsGain > VL6180_ALS_GAIN_40) {
        return 0.0f;
    }

    float gain = gainFactors[dev->alsGain];
    float integrationTime = dev->alsIntegrationPeriod / 100.0f; // Convert to seconds

    // Calculate lux using the formula from datasheet
    float lux = (float)alsValue * 0.32f / (gain * integrationTime);

    return lux;
}

/**
 * @brief Get error string description
 * @param errorCode Error code
 * @return Error string
 */
const char* VL6180_GetErrorString(uint8_t errorCode)
{
    switch (errorCode) {
        case VL6180_ERROR_NONE:
            return "No error";
        case VL6180_ERROR_SYSERR_1:
            return "System error 1";
        case VL6180_ERROR_SYSERR_5:
            return "System error 5";
        case VL6180_ERROR_ECEFAIL:
            return "ECE failure";
        case VL6180_ERROR_NOCONVERGE:
            return "No convergence";
        case VL6180_ERROR_RANGEIGNORE:
            return "Range ignore";
        case VL6180_ERROR_SNR:
            return "SNR error";
        case VL6180_ERROR_RAWUFLOW:
            return "Raw underflow";
        case VL6180_ERROR_RAWOFLOW:
            return "Raw overflow";
        case VL6180_ERROR_RANGEUFLOW:
            return "Range underflow";
        case VL6180_ERROR_RANGEOFLOW:
            return "Range overflow";
        default:
            return "Unknown error";
    }
}

/******************************* Usage Examples ******************************/

/*
// Example 1: Basic VL6180 usage for range measurement
#include "VL6180_ATY.h"

// I2C function implementations (platform specific)
uint8_t i2c_start(void) { // Your I2C start implementation }
uint8_t i2c_stop(void) { // Your I2C stop implementation }
uint8_t i2c_write_byte(uint8_t data) { // Your I2C write implementation }
uint8_t i2c_read_byte(uint8_t ack) { // Your I2C read implementation }
void delay_ms(uint32_t ms) { // Your delay implementation }
void debug_log(const char* format, ...) { // Your log implementation }

int main(void)
{
    // Initialize VL6180 device structure
    struct VL6180_ATY_Dev vl6180_dev = {
        .i2cStart = i2c_start,
        .i2cStop = i2c_stop,
        .i2cWriteByte = i2c_write_byte,
        .i2cReadByte = i2c_read_byte,
        .delayMs = delay_ms,
        .i2cAddress = VL6180_I2C_ADDR_DEFAULT,
        .debugEnable = 1,
        .LOG = debug_log,
        .initialized = 0  // Auto-initialization will be triggered
    };

    // VL6180_Init will be called automatically in VL6180_StartRangeMeasurement
    
    while (1) {
        // Start single-shot range measurement
        if (VL6180_StartRangeMeasurement(&vl6180_dev, VL6180_MODE_RANGE_SINGLE_SHOT) == VL6180_STATUS_OK) {
            // Wait for measurement to complete
            while (!VL6180_IsRangeReady(&vl6180_dev)) {
                delay_ms(1);
            }
            
            // Read range result
            if (VL6180_ReadRangeResult(&vl6180_dev) == VL6180_STATUS_OK) {
                uint8_t range = VL6180_GetRangeValue(&vl6180_dev);
                debug_log("Range: %d mm\n", range);
            }
            
            // Clear interrupt
            VL6180_ClearRangeInterrupt(&vl6180_dev);
        }
        
        delay_ms(100);
    }
}

// Example 2: VL6180 ALS (Ambient Light Sensor) usage
int als_example(void)
{
    struct VL6180_ATY_Dev vl6180_dev = {
        .i2cStart = i2c_start,
        .i2cStop = i2c_stop,
        .i2cWriteByte = i2c_write_byte,
        .i2cReadByte = i2c_read_byte,
        .delayMs = delay_ms,
        .i2cAddress = VL6180_I2C_ADDR_DEFAULT,
        .debugEnable = 1,
        .LOG = debug_log,
        .initialized = 0  // Auto-initialization will be triggered
    };

    // Configure ALS settings
    VL6180_SetALSGain(&vl6180_dev, VL6180_ALS_GAIN_1);
    VL6180_SetALSIntegrationPeriod(&vl6180_dev, 100);

    while (1) {
        // Start single-shot ALS measurement
        if (VL6180_StartALSMeasurement(&vl6180_dev, VL6180_MODE_ALS_SINGLE_SHOT) == VL6180_STATUS_OK) {
            // Wait for measurement to complete
            while (!VL6180_IsALSReady(&vl6180_dev)) {
                delay_ms(1);
            }
            
            // Read ALS result
            if (VL6180_ReadALSResult(&vl6180_dev) == VL6180_STATUS_OK) {
                uint16_t als_counts = VL6180_GetALSValue(&vl6180_dev);
                float lux = VL6180_ConvertALSToLux(&vl6180_dev, als_counts);
                debug_log("ALS: %d counts, %.2f lux\n", als_counts, lux);
            }
            
            // Clear interrupt
            VL6180_ClearALSInterrupt(&vl6180_dev);
        }
        
        delay_ms(500);
    }
}
*/

/******************************** End Of File *********************************/