#include "nbus_app.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 receiveOneByte(){
	nBus.hw_platform->uart_abort_receive();
	nBus.hw_platform->uart_receive(nBus.rx_buffer, 1);
	nBus.uart_state = UART_RX_1B;
	nBus.rx_length = 1;
}

inline static void receiveNBytes(uint8_t n){
	nBus.rx_length = n;
	nBus.hw_platform->uart_receive(nBus.rx_buffer, nBus.rx_length);
	nBus.uart_state = UART_RX_PAYLOAD;
}

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;
		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

}

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

void nbus_cb_UART_RX(void){
	if(nBus.uart_state == UART_RX_PAYLOAD) {
		nBus.uart_state = UART_RECEIVED;
		nBus.hw_platform->timer_uart_stop();
	}

	if(nBus.uart_state == UART_RX_1B) {
		nBus.hw_platform->led_on();
		if(nBus.rx_buffer[0] > 0) {
			receiveNBytes(nBus.rx_buffer[0]);
			nBus.hw_platform->timer_uart_stop();
			nBus.hw_platform->timer_uart_start(nBus.rx_buffer[0]);
		} else {
			receiveOneByte();
		}
	}

}


void nbus_cb_TIM_periodElapsed(void) {
	if(nBus.uart_state == UART_RX_PAYLOAD) {
		nBus.hw_platform->led_off();
		nBus.hw_platform->timer_uart_stop();
		nBus.hw_platform->uart_abort_receive();
		receiveOneByte();
	}
}



/* -------------------------------------------------------- */
/* ------------------ PUBLIC 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;

  // init restart timer
  nBus.uart_state = UART_RX_1B;
  nBus.hw_platform->timer_uart_start(100);	 // dummy value
  nBus.hw_platform->timer_uart_stop();

  nBus.interface = interface;
  receiveOneByte();

}

void nbus_init_app(void *hw_interface, void *hw_config){
	nBus.interface->init(hw_interface, hw_config);
}

void nbus_init_memory_driver(nBus_MemoryDriver *memDriver, uint16_t capacity){
	nbus_memory_init(memDriver);
	nBus.memoryInterface = getnbusMemoryInterface();
}

void nbus_stack(void){

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

			process_request();

			// ready for next receiving
			receiveOneByte();

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

}