/*********************************************************************
 This is an example for our nRF52 based Bluefruit LE modules

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 MIT license, check LICENSE for more information
 All text above, and the splash screen below must be included in
 any redistribution
*********************************************************************/

/*
 * This sketch demonstrate how to run both Central and Peripheral roles
 * at the same time. It will act as a relay between an central (mobile)
 * to another peripheral using bleuart service.
 * 
 * Mobile <--> DualRole <--> peripheral Ble Uart
 */
#include <bluefruit.h>

// Peripheral uart service
BLEUart bleuart;

// Central uart client
BLEClientUart clientUart;

void setup()
{
  Serial.begin(115200);
  while ( !Serial ) delay(10);   // for nrf52840 with native usb

  Serial.println("Bluefruit52 Dual Role BLEUART Example");
  Serial.println("-------------------------------------\n");
  
  // Initialize Bluefruit with max concurrent connections as Peripheral = 1, Central = 1
  // SRAM usage required by SoftDevice will increase with number of connections
  Bluefruit.begin(1, 1);
  // Set max power. Accepted values are: -40, -30, -20, -16, -12, -8, -4, 0, 4
  Bluefruit.setTxPower(4);
  Bluefruit.setName("Bluefruit52 duo");

  // Callbacks for Peripheral
  Bluefruit.setConnectCallback(prph_connect_callback);
  Bluefruit.setDisconnectCallback(prph_disconnect_callback);

  // Callbacks for Central
  Bluefruit.Central.setConnectCallback(cent_connect_callback);
  Bluefruit.Central.setDisconnectCallback(cent_disconnect_callback);

  // Configure and Start BLE Uart Service
  bleuart.begin();
  bleuart.setRxCallback(prph_bleuart_rx_callback);

  // Init BLE Central Uart Serivce
  clientUart.begin();
  clientUart.setRxCallback(cent_bleuart_rx_callback);


  /* Start Central Scanning
   * - Enable auto scan if disconnected
   * - Interval = 100 ms, window = 80 ms
   * - Filter only accept bleuart service
   * - Don't use active scan
   * - Start(timeout) with timeout = 0 will scan forever (until connected)
   */
  Bluefruit.Scanner.setRxCallback(scan_callback);
  Bluefruit.Scanner.restartOnDisconnect(true);
  Bluefruit.Scanner.setInterval(160, 80); // in unit of 0.625 ms
  Bluefruit.Scanner.filterUuid(bleuart.uuid);
  Bluefruit.Scanner.useActiveScan(false);
  Bluefruit.Scanner.start(0);                   // 0 = Don't stop scanning after n seconds

  // Set up and start advertising
  startAdv();
}

void startAdv(void)
{
  // Advertising packet
  Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);
  Bluefruit.Advertising.addTxPower();

  // Include bleuart 128-bit uuid
  Bluefruit.Advertising.addService(bleuart);

  // Secondary Scan Response packet (optional)
  // Since there is no room for 'Name' in Advertising packet
  Bluefruit.ScanResponse.addName();

  /* Start Advertising
   * - Enable auto advertising if disconnected
   * - Interval:  fast mode = 20 ms, slow mode = 152.5 ms
   * - Timeout for fast mode is 30 seconds
   * - Start(timeout) with timeout = 0 will advertise forever (until connected)
   *
   * For recommended advertising interval
   * https://developer.apple.com/library/content/qa/qa1931/_index.html
   */
  Bluefruit.Advertising.restartOnDisconnect(true);
  Bluefruit.Advertising.setInterval(32, 244);    // in unit of 0.625 ms
  Bluefruit.Advertising.setFastTimeout(30);      // number of seconds in fast mode
  Bluefruit.Advertising.start(0);                // 0 = Don't stop advertising after n seconds
}

void loop()
{
  // do nothing, all the work is done in callback
}

/*------------------------------------------------------------------*/
/* Peripheral
 *------------------------------------------------------------------*/
void prph_connect_callback(uint16_t conn_handle)
{
  char peer_name[32] = { 0 };
  Bluefruit.Gap.getPeerName(conn_handle, peer_name, sizeof(peer_name));

  Serial.print("[Prph] Connected to ");
  Serial.println(peer_name);
}

void prph_disconnect_callback(uint16_t conn_handle, uint8_t reason)
{
  (void) conn_handle;
  (void) reason;

  Serial.println();
  Serial.println("[Prph] Disconnected");
}

void prph_bleuart_rx_callback(void)
{
  // Forward data from Mobile to our peripheral
  char str[20+1] = { 0 };
  bleuart.read(str, 20);

  Serial.print("[Prph] RX: ");
  Serial.println(str);  

  if ( clientUart.discovered() )
  {
    clientUart.print(str);
  }else
  {
    bleuart.println("[Prph] Central role not connected");
  }
}

/*------------------------------------------------------------------*/
/* Central
 *------------------------------------------------------------------*/
void scan_callback(ble_gap_evt_adv_report_t* report)
{
  // Since we configure the scanner with filterUuid()
  // Scan callback only invoked for device with bleuart service advertised  
  // Connect to the device with bleuart service in advertising packet  
  Bluefruit.Central.connect(report);
}

void cent_connect_callback(uint16_t conn_handle)
{
  char peer_name[32] = { 0 };
  Bluefruit.Gap.getPeerName(conn_handle, peer_name, sizeof(peer_name));

  Serial.print("[Cent] Connected to ");
  Serial.println(peer_name);;

  if ( clientUart.discover(conn_handle) )
  {
    // Enable TXD's notify
    clientUart.enableTXD();
  }else
  {
    // disconect since we couldn't find bleuart service
    Bluefruit.Central.disconnect(conn_handle);
  }  
}

void cent_disconnect_callback(uint16_t conn_handle, uint8_t reason)
{
  (void) conn_handle;
  (void) reason;
  
  Serial.println("[Cent] Disconnected");
}

/**
 * Callback invoked when uart received data
 * @param cent_uart Reference object to the service where the data 
 * arrived. In this example it is clientUart
 */
void cent_bleuart_rx_callback(BLEClientUart& cent_uart)
{
  char str[20+1] = { 0 };
  cent_uart.read(str, 20);
      
  Serial.print("[Cent] RX: ");
  Serial.println(str);

  if ( bleuart.notifyEnabled() )
  {
    // Forward data from our peripheral to Mobile
    bleuart.print( str );
  }else
  {
    // response with no prph message
    clientUart.println("[Cent] Peripheral role not connected");
  }  
}