/*!
 * \file      main.c
 *
 * \brief     Ping-Pong implementation
 *
 * \copyright Revised BSD License, see section \ref LICENSE.
 *
 * \code
 *                ______                              _
 *               / _____)             _              | |
 *              ( (____  _____ ____ _| |_ _____  ____| |__
 *               \____ \| ___ |    (_   _) ___ |/ ___)  _ \
 *               _____) ) ____| | | || |_| ____( (___| | | |
 *              (______/|_____)_|_|_| \__)_____)\____)_| |_|
 *              (C)2013-2017 Semtech
 *
 * \endcode
 *
 * \author    Miguel Luis ( Semtech )
 *
 * \author    Gregory Cristian ( Semtech )
 */
#include <string.h>
#include "board.h"
#include "gpio.h"
#include "delay.h"
#include "timer.h"
#include "radio.h"

#if defined( REGION_AS923 )

#define RF_FREQUENCY                                923000000 // Hz

#elif defined( REGION_AU915 )

#define RF_FREQUENCY                                915000000 // Hz

#elif defined( REGION_CN779 )

#define RF_FREQUENCY                                779000000 // Hz

#elif defined( REGION_EU868 )

#define RF_FREQUENCY                                868000000 // Hz

#elif defined( REGION_KR920 )

#define RF_FREQUENCY                                920000000 // Hz

#elif defined( REGION_IN865 )

#define RF_FREQUENCY                                865000000 // Hz

#elif defined( REGION_US915 )

#define RF_FREQUENCY                                915000000 // Hz

#elif defined( REGION_RU864 )

#define RF_FREQUENCY                                864000000 // Hz

#else
    #error "Please define a frequency band in the compiler options."
#endif

#define TX_OUTPUT_POWER                             14        // dBm

#if defined( USE_MODEM_LORA )

#define LORA_BANDWIDTH                              0         // [0: 125 kHz,
                                                              //  1: 250 kHz,
                                                              //  2: 500 kHz,
                                                              //  3: Reserved]
#define LORA_SPREADING_FACTOR                       7         // [SF7..SF12]
#define LORA_CODINGRATE                             1         // [1: 4/5,
                                                              //  2: 4/6,
                                                              //  3: 4/7,
                                                              //  4: 4/8]
#define LORA_PREAMBLE_LENGTH                        8         // Same for Tx and Rx
#define LORA_SYMBOL_TIMEOUT                         5         // Symbols
#define LORA_FIX_LENGTH_PAYLOAD_ON                  false
#define LORA_IQ_INVERSION_ON                        false

#elif defined( USE_MODEM_FSK )

#define FSK_FDEV                                    25000     // Hz
#define FSK_DATARATE                                50000     // bps
#define FSK_BANDWIDTH                               50000     // Hz
#define FSK_AFC_BANDWIDTH                           83333     // Hz
#define FSK_PREAMBLE_LENGTH                         5         // Same for Tx and Rx
#define FSK_FIX_LENGTH_PAYLOAD_ON                   false

#else
    #error "Please define a modem in the compiler options."
#endif

typedef enum
{
    LOWPOWER,
    RX,
    RX_TIMEOUT,
    RX_ERROR,
    TX,
    TX_TIMEOUT,
}States_t;

#define RX_TIMEOUT_VALUE                            1000
#define BUFFER_SIZE                                 64 // Define the payload size here

const uint8_t PingMsg[] = "PING";
const uint8_t PongMsg[] = "PONG";

uint16_t BufferSize = BUFFER_SIZE;
uint8_t Buffer[BUFFER_SIZE];

States_t State = LOWPOWER;

int8_t RssiValue = 0;
int8_t SnrValue = 0;

/*!
 * Radio events function pointer
 */
static RadioEvents_t RadioEvents;

/*!
 * LED GPIO pins objects
 */
extern Gpio_t Led3;
extern Gpio_t Led4;

/*!
 * \brief Function to be executed on Radio Tx Done event
 */
void OnTxDone( void );

/*!
 * \brief Function to be executed on Radio Rx Done event
 */
void OnRxDone( uint8_t *payload, uint16_t size, int16_t rssi, int8_t snr );

/*!
 * \brief Function executed on Radio Tx Timeout event
 */
void OnTxTimeout( void );

/*!
 * \brief Function executed on Radio Rx Timeout event
 */
void OnRxTimeout( void );

/*!
 * \brief Function executed on Radio Rx Error event
 */
void OnRxError( void );

/**
 * Main application entry point.
 */
int main( void )
{
    bool isMaster = true;
    uint8_t i;

    // Target board initialization
    BoardInitMcu( );
    BoardInitPeriph( );

    // Radio initialization
    RadioEvents.TxDone = OnTxDone;
    RadioEvents.RxDone = OnRxDone;
    RadioEvents.TxTimeout = OnTxTimeout;
    RadioEvents.RxTimeout = OnRxTimeout;
    RadioEvents.RxError = OnRxError;

    Radio.Init( &RadioEvents );

    Radio.SetChannel( RF_FREQUENCY );

#if defined( USE_MODEM_LORA )

    Radio.SetTxConfig( MODEM_LORA, TX_OUTPUT_POWER, 0, LORA_BANDWIDTH,
                                   LORA_SPREADING_FACTOR, LORA_CODINGRATE,
                                   LORA_PREAMBLE_LENGTH, LORA_FIX_LENGTH_PAYLOAD_ON,
                                   true, 0, 0, LORA_IQ_INVERSION_ON, 3000 );

    Radio.SetRxConfig( MODEM_LORA, LORA_BANDWIDTH, LORA_SPREADING_FACTOR,
                                   LORA_CODINGRATE, 0, LORA_PREAMBLE_LENGTH,
                                   LORA_SYMBOL_TIMEOUT, LORA_FIX_LENGTH_PAYLOAD_ON,
                                   0, true, 0, 0, LORA_IQ_INVERSION_ON, true );

    Radio.SetMaxPayloadLength( MODEM_LORA, BUFFER_SIZE );

#elif defined( USE_MODEM_FSK )

    Radio.SetTxConfig( MODEM_FSK, TX_OUTPUT_POWER, FSK_FDEV, 0,
                                  FSK_DATARATE, 0,
                                  FSK_PREAMBLE_LENGTH, FSK_FIX_LENGTH_PAYLOAD_ON,
                                  true, 0, 0, 0, 3000 );

    Radio.SetRxConfig( MODEM_FSK, FSK_BANDWIDTH, FSK_DATARATE,
                                  0, FSK_AFC_BANDWIDTH, FSK_PREAMBLE_LENGTH,
                                  0, FSK_FIX_LENGTH_PAYLOAD_ON, 0, true,
                                  0, 0,false, true );

    Radio.SetMaxPayloadLength( MODEM_FSK, BUFFER_SIZE );

#else
    #error "Please define a frequency band in the compiler options."
#endif

    Radio.Rx( RX_TIMEOUT_VALUE );

    while( 1 )
    {
        switch( State )
        {
        case RX:
            if( isMaster == true )
            {
                if( BufferSize > 0 )
                {
                    if( strncmp( ( const char* )Buffer, ( const char* )PongMsg, 4 ) == 0 )
                    {
                        // Indicates on a LED that the received frame is a PONG
                        GpioToggle( &Led4 );

                        // Send the next PING frame
                        Buffer[0] = 'P';
                        Buffer[1] = 'I';
                        Buffer[2] = 'N';
                        Buffer[3] = 'G';
                        // We fill the buffer with numbers for the payload
                        for( i = 4; i < BufferSize; i++ )
                        {
                            Buffer[i] = i - 4;
                        }
                        DelayMs( 1 );
                        Radio.Send( Buffer, BufferSize );
                    }
                    else if( strncmp( ( const char* )Buffer, ( const char* )PingMsg, 4 ) == 0 )
                    { // A master already exists then become a slave
                        isMaster = false;
                        GpioToggle( &Led3 ); // Set LED off
                        Radio.Rx( RX_TIMEOUT_VALUE );
                    }
                    else // valid reception but neither a PING or a PONG message
                    {    // Set device as master ans start again
                        isMaster = true;
                        Radio.Rx( RX_TIMEOUT_VALUE );
                    }
                }
            }
            else
            {
                if( BufferSize > 0 )
                {
                    if( strncmp( ( const char* )Buffer, ( const char* )PingMsg, 4 ) == 0 )
                    {
                        // Indicates on a LED that the received frame is a PING
                        GpioToggle( &Led4 );

                        // Send the reply to the PONG string
                        Buffer[0] = 'P';
                        Buffer[1] = 'O';
                        Buffer[2] = 'N';
                        Buffer[3] = 'G';
                        // We fill the buffer with numbers for the payload
                        for( i = 4; i < BufferSize; i++ )
                        {
                            Buffer[i] = i - 4;
                        }
                        DelayMs( 1 );
                        Radio.Send( Buffer, BufferSize );
                    }
                    else // valid reception but not a PING as expected
                    {    // Set device as master and start again
                        isMaster = true;
                        Radio.Rx( RX_TIMEOUT_VALUE );
                    }
                }
            }
            State = LOWPOWER;
            break;
        case TX:
            // Indicates on a LED that we have sent a PING [Master]
            // Indicates on a LED that we have sent a PONG [Slave]
            GpioToggle( &Led3 );
            Radio.Rx( RX_TIMEOUT_VALUE );
            State = LOWPOWER;
            break;
        case RX_TIMEOUT:
        case RX_ERROR:
            if( isMaster == true )
            {
                // Send the next PING frame
                Buffer[0] = 'P';
                Buffer[1] = 'I';
                Buffer[2] = 'N';
                Buffer[3] = 'G';
                for( i = 4; i < BufferSize; i++ )
                {
                    Buffer[i] = i - 4;
                }
                DelayMs( 1 );
                Radio.Send( Buffer, BufferSize );
            }
            else
            {
                Radio.Rx( RX_TIMEOUT_VALUE );
            }
            State = LOWPOWER;
            break;
        case TX_TIMEOUT:
            Radio.Rx( RX_TIMEOUT_VALUE );
            State = LOWPOWER;
            break;
        case LOWPOWER:
        default:
            // Set low power
            break;
        }

        BoardLowPowerHandler( );

    }
}

void OnTxDone( void )
{
    Radio.Sleep( );
    State = TX;
}

void OnRxDone( uint8_t *payload, uint16_t size, int16_t rssi, int8_t snr )
{
    Radio.Sleep( );
    BufferSize = size;
    memcpy( Buffer, payload, BufferSize );
    RssiValue = rssi;
    SnrValue = snr;
    State = RX;
}

void OnTxTimeout( void )
{
    Radio.Sleep( );
    State = TX_TIMEOUT;
}

void OnRxTimeout( void )
{
    Radio.Sleep( );
    State = RX_TIMEOUT;
}

void OnRxError( void )
{
    Radio.Sleep( );
    State = RX_ERROR;
}