#include "nbus_app.h"
#include <string.h>

nBus_TypeDef nBus;

static uint8_t const crc8x_table[] = {
    0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15, 0x38, 0x3F, 0x36, 0x31, 0x24, 0x23, 0x2A, 0x2D, 0x70, 0x77, 0x7E,
    0x79, 0x6C, 0x6B, 0x62, 0x65, 0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D, 0xE0, 0xE7, 0xEE, 0xE9, 0xFC, 0xFB,
    0xF2, 0xF5, 0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD, 0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85, 0xA8,
    0xAF, 0xA6, 0xA1, 0xB4, 0xB3, 0xBA, 0xBD, 0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2, 0xFF, 0xF8, 0xF1, 0xF6,
    0xE3, 0xE4, 0xED, 0xEA, 0xB7, 0xB0, 0xB9, 0xBE, 0xAB, 0xAC, 0xA5, 0xA2, 0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D,
    0x9A, 0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32, 0x1F, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0D, 0x0A, 0x57, 0x50,
    0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42, 0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A, 0x89, 0x8E, 0x87, 0x80, 0x95,
    0x92, 0x9B, 0x9C, 0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4, 0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC,
    0xC1, 0xC6, 0xCF, 0xC8, 0xDD, 0xDA, 0xD3, 0xD4, 0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C, 0x51, 0x56, 0x5F,
    0x58, 0x4D, 0x4A, 0x43, 0x44, 0x19, 0x1E, 0x17, 0x10, 0x05, 0x02, 0x0B, 0x0C, 0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A,
    0x33, 0x34, 0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B, 0x76, 0x71, 0x78, 0x7F, 0x6A, 0x6D, 0x64, 0x63, 0x3E,
    0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B, 0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13, 0xAE, 0xA9, 0xA0, 0xA7,
    0xB2, 0xB5, 0xBC, 0xBB, 0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83, 0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC,
    0xCB, 0xE6, 0xE1, 0xE8, 0xEF, 0xFA, 0xFD, 0xF4, 0xF3};

/* -------------------------------------------------------- */
/* ------------------ PRIVATE FUNCTIONS-------------------- */
/* -------------------------------------------------------- */

static uint8_t crc8x_fast(void const *mem, uint16_t len)
{
    uint8_t crc = CRC8_INIT_VALUE;
    uint8_t const *data = (uint8_t *)mem;
    if (data == NULL)
        return 0xff;
    crc &= 0xff;
    while (len--)
        crc = crc8x_table[crc ^ *data++];
    return crc;
}

inline static void receivePacket(void)
{
    nBus.hw_platform->uart_receive(nBus.rx_buffer, 64);
}

inline static void send_response()
{
    if (nBus.send_response == SEND_RESPONSE)
    {
        nBus.tx_buffer[0] -= 1; // prvý bajt sa nepočíta
        nBus.hw_platform->uart_transmit(nBus.tx_buffer, nBus.tx_length);
    }
    nBus.hw_platform->led_off();
}

#if MODULE_MASTER == 1
inline static void receive_slave_response()
{
}
#endif

static nBusCommandType_t get_request_type()
{
    nBus.addressModule = nBus.rx_buffer[0];
    nBus.sensorInfo = *(const nBus_sensorByte_t *)&nBus.rx_buffer[1];
    nBus.function_code = *(const nBus_functionCode_t *)&nBus.rx_buffer[2];

    if (nBus.sensorInfo.address != 0 && nBus.addressModule != 0)
    {
        nBus.request_type = UNICAST_TO_SENSOR;
        return UNICAST_TO_SENSOR;
    }

    if (nBus.sensorInfo.address == 0 && nBus.addressModule != 0)
    {
        nBus.request_type = UNICAST_TO_MODULE;
        return UNICAST_TO_MODULE;
    }

    if (nBus.sensorInfo.address != 0 && nBus.addressModule == 0)
    {
        nBus.request_type = BROADCAST_SPECIFIC_SENSORS;
        return BROADCAST_SPECIFIC_SENSORS;
    }

    nBus.request_type = BROADCAST_GLOBAL;
    return BROADCAST_GLOBAL;
}

static void process_request()
{
    nBusCommandType_t request_type = get_request_type();
    nBus.send_response = SEND_RESPONSE;

    nBus.tx_buffer[0] = 0;
    nBus.tx_buffer[1] = nBus.rx_buffer[0]; // Module address
    nBus.tx_buffer[2] = nBus.rx_buffer[1]; // Sensor address

    uint8_t crcC = crc8x_fast(nBus.rx_buffer, nBus.rx_length - 1);
    if (crcC != nBus.rx_buffer[nBus.rx_length - 1])
    {
        nBus.send_response = NO_RESPONSE;
        return;
    }

#if MODULE_SLAVE == 1
    // spracovanie broadcast komunikacie
    if ((request_type == BROADCAST_SPECIFIC_SENSORS || request_type == BROADCAST_GLOBAL))
    {
        nbus_slave_broadcast(&nBus, request_type);
        return;
    }
#endif

    // paket nie je adresovany tomuto modulu
    if (nBus.addressModule != MODULE_ADDRESS)
    {
        nBus.send_response = NO_RESPONSE;
        receivePacket();
        return;
    }

    nBus.function_code.error = 0;
    nBus.tx_length = META_SIZE;

#if MODULE_SLAVE == 1
    if (nBus.function_code.notReadWrite == REQUEST_GET)
    {
        if (request_type == UNICAST_TO_SENSOR)
        {
            nbus_slave_unicastToSensorGet(&nBus);
        }

        if (request_type == UNICAST_TO_MODULE)
        {
            nbus_slave_unicastToModuleGet(&nBus);
        }
    }
    else
    {
        // else request is REQUEST_SET
        if (request_type == UNICAST_TO_SENSOR)
        {
            nbus_slave_unicastToSensorSet(&nBus);
        }

        if (request_type == UNICAST_TO_MODULE)
        {
            nbus_slave_unicastToModuleSet(&nBus);
        }
    }

    nBus.tx_buffer[3] = *(uint8_t *)&nBus.function_code;
    nBus.tx_buffer[nBus.tx_length - 1] = crc8x_fast(&nBus.tx_buffer[1], nBus.tx_length - 2);
    nBus.tx_buffer[0] = nBus.tx_length;
#endif

#if MODULE_MASTER == 1
    if (nBus.function_code.notReadWrite == REQUEST_GET)
    {
        nbus_master_unicastToModuleGet(&nBus);
    }
    else
    {
        nbus_master_unicastToModuleSet(&nBus);
    }
#endif
}

static void nbus_blink_LED(uint8_t delay)
{
    nBus.hw_platform->led_on();
    nBus.hw_platform->delay_ms(delay);
    nBus.hw_platform->led_off();
    nBus.hw_platform->delay_ms(delay);
    nBus.hw_platform->led_on();
    nBus.hw_platform->delay_ms(delay);
    nBus.hw_platform->led_off();
    nBus.hw_platform->delay_ms(delay);
}

/* -------------------------------------------------------- */
/* ----------------------- CALLBACKS----------------------- */
/* -------------------------------------------------------- */

/**
 * @brief UART receive complete.
 * This callback have to called from application, when RX data is ready.
 * @param int size Size of received packet
 * Received packet is located in uBus.rx_buffer
 */
void nbus_cb_UART_RX(int size)
{
    nBus.rx_length = size;
    nBus.uart_state = UART_RX_RECEIVED;
}

/* -------------------------------------------------------- */
/* ------------------ PUBLIC FUNCTIONS-------------------- */
/* -------------------------------------------------------- */

/**
 * @brief Initialize of nBus stack
 * @param interface Driver for module application.
 * 		Every application have to implement base functions as Init,
 * Reset, GetData, SetData, GetParam, SetParam, .... @see nBusAppInterface_t
 * These are application dependent functions.
 * @param hw Application level implementation of base functions (uart_receive,
 * uart_transmit, led_on/off/toggle, ...). These are MCU dependent functions.
 */
void nbus_init(nBusAppInterface_t *interface, nBusPlatformInterface_t *hw)
{
    nBus.hw_platform = hw;

    nBus.rx_length = 0;
    nBus.data_timebase = 0;
    nBus.measure_active = MEASURE_STOPPED;

    nBus.uart_state = UART_RX_WAIT;

    nBus.interface = interface;

    receivePacket();
}

/**
 * @brief Initialize concrete application, if it is needed.
 * This function call "init()" function from nBusPlatformInterface_t, and this
 * function is implemented in concrete application.
 * @param hw_interface Pointer to hardware definition structure. In STM32 it can
 * be hSPI, hUART, hADC, ...
 * @param hw_config configuration for hardware structure object.
 */
void nbus_init_app(void *hw_interface, void *hw_config)
{
    nBus.interface->init(hw_interface, hw_config);
}

/**
 * @brief Init memory driver for storing module/sensor parameters.
 * Implementation of memory driver is independent from nBus. To provide
 * nonvolatile parameters store, is needed implement this driver.
 * @param memDriver Memory driver for bas operation: read/write 1/2/4 byte
 * from/to memory
 * @todo implement capacity parameter
 */
void nbus_init_memory_driver(nBus_MemoryDriver *memDriver)
{
    nbus_memory_init(memDriver);
    nBus.memoryInterface = getnbusMemoryInterface();
    nbus_blink_LED(100);

    nBus.memoryInterface->readHeaderData();

    uint8_t *params = nbus_interface_allParams();
    uint8_t paramCnt = nbus_interface_allParamsCount();
    uint32_t paramValue;
    for (uint32_t index = 1; index <= nBus.interface->getSensorCount(); index++)
    {
        for (int paramIndex = 0; paramIndex < paramCnt; paramIndex++)
        {
            if (nbus_is_param_active(index, params[paramIndex]))
            {
                if (nBus.interface->hasParam(index, params[paramIndex]))
                {
                    paramValue = nbus_memory_read_param(index, params[paramIndex]);
                    nBus.interface->setParam(index, params[paramIndex], paramValue);
                }
            }
        }
    }
}

/**
 * @brief Run protocol stack.
 * This is infinity protocol loop.
 * When stack is started (or reset) it blink as boot sign.
 *
 * Content of loop:
 * - if data was received: process request. Determine addressee and type of
 * request
 * - execute request or discard request
 * - send response (only for unicast requests)
 *
 * In each iteration, the state of application flags are performed. The state of
 * application is noticed from loop_callback() (if it is defined). Meaning of
 * return values:
 * - 0 - No event occurs,
 * - 1 - data from connected sensors are prepared, it will be read with read()
 * function automatically.
 * - 2 - communication error/timeout. The reception of packed process will be
 * reset.
 */
void nbus_stack(void)
{

    nbus_blink_LED(50);

    while (1)
    {
        if (nBus.uart_state == UART_RX_RECEIVED)
        {

            process_request();
            nBus.uart_state = UART_RX_WAIT;

            send_response();
#if MODULE_MASTER == 1
            receive_slave_response();
#endif
        }

        if (nBus.hw_platform->loop_callback != NULL)
        {
            if (nBus.hw_platform->loop_callback(CallbackType_SENSOR) == 1)
            {
                nBus.interface->read();
            }

            if (nBus.hw_platform->loop_callback(CallbackType_UART) == 1)
            {
                nBus.uart_state = UART_RX_WAIT;
            }
        }
    }
}