#include "Bluetooth.h"
#include "pins.h"
#include "Protocol.h"
#include "debugport.h"

#ifdef TELNET
#define PRNT Debug
#endif

#ifndef TELNET
#define PRNT Serial
#endif


#ifdef ESP32

#define ESP32_USE_HC05

const int LED = 2;

// ESP32

sRxLine RxLine;

#ifdef ESP32_USE_HC05

//static HardwareSerial& Bluetooth(Serial2); // TODO: make proper ESP32 BT client

bool Bluetooth_ATCommand(const char* cmd);


// Search for a HC-05 BlueTooth adapter, trying the more common baud rates first.
// As we cannot power up with the key pin high we are at the mercy of the baud rate 
// stored in the module.
// **IMPORTANT** 
//     We must use a HC-05 module that uses a 3 pin 3.3V regulator (NOT 5 pin).
//     On those modules, the EN input drive pin 34 and can be used to switch to AT 
//     command mode from data mode by raising EN high.
//  ** BEWARE** 
//     The other style modules (with a 5 pin regulator) will disable the HC-05's power
//     when the EN pin is low!!!!
//
// Once in command mode we can start interrogating using a simple "AT" command and 
// checking for a response.
// If no response, try another baud rate till we do find a response.
// We can then proceed and configure the device's name, and force 9600 data rate

void Bluetooth_Init()
{
  const int BTRates[] = {
    9600, 38400, 115200, 19200, 57600, 2400, 4800, 1200
  };

  RxLine.clear();

  // attach to the SENSE line from the HC-05 module
  // this line goes high when a BT client is connected :-)
  pinMode(HC05_Sense, INPUT);              
  
  digitalWrite(KeyPin, HIGH);              // request HC-05 module to enter command mode
  // Open Serial2, explicitly specify pins for pin multiplexer!);   
  Serial2.begin(9600, SERIAL_8N1, Rx2Pin, Tx2Pin);  

  PRNT.println("\r\n\r\nAttempting to detect HC-05 Bluetooth module...");

  int BTidx = 0;
  int maxTries =  sizeof(BTRates)/sizeof(int);
  for(BTidx = 0; BTidx < maxTries; BTidx++) {
    PRNT.print("  @ ");
    PRNT.print(BTRates[BTidx]);
    PRNT.print(" baud... ");
    Serial2.begin(BTRates[BTidx], SERIAL_8N1, Rx2Pin, Tx2Pin);   // open serial port at a std.baud rate
    delay(10);
    Serial2.print("\r\n");      // clear the throat!
    delay(100);
    Serial2.setTimeout(100);

    if(Bluetooth_ATCommand("AT\r\n")) {   // probe with a simple "AT"
      PRNT.println(" OK.");          // got a response - woo hoo found the module!
      break;
    }
    if(Bluetooth_ATCommand("AT\r\n")) {   // sometimes a second try is good...
      PRNT.println(" OK.");
      break;
    }

    // failed, try another baud rate
    PRNT.println("");
    Serial2.flush();
    Serial2.end();
    delay(100);
  }

  PRNT.println("");
  if(BTidx == maxTries) {
    // we could not get anywhere with teh AT commands, but maybe this is the other module
    // plough on and assume 9600 baud, but at the mercy of whatever the module name is...
    PRNT.println("FAILED to detect a HC-05 Bluetooth module :-(");
    // leave the EN pin high - if other style module keeps it powered!

    // assume it is 9600, and just (try to) use it like that...
    // we will sense the STATE line to prove a client is hanging off the link...
    PRNT.println("ASSUMING a HC-05 module @ 9600baud (Unknown name)");
    Serial2.begin(9600, SERIAL_8N1, Rx2Pin, Tx2Pin);
  }
  else {
    // found a HC-05 module at one of its supported baud rates.
    // now program it's name and force a 9600 baud data interface.
    // this is the defacto standard as shipped!

    PRNT.println("HC-05 found");

    do {   // so we can break!
      PRNT.print("  Setting Name to \"Diesel Heater\"... ");
      if(!Bluetooth_ATCommand("AT+NAME=\"Diesel Heater\"\r\n")) {
        PRNT.println("FAILED");
        break;
      }
      PRNT.println("OK");

      PRNT.print("  Setting baud rate to 9600N81...");
      if(!Bluetooth_ATCommand("AT+UART=9600,1,0\r\n")) {
        PRNT.println("FAILED");
        break;
      };
      PRNT.println("OK");

      Serial2.begin(9600, SERIAL_8N1, Rx2Pin, Tx2Pin);

      // leave HC-05 command mode, return to data mode
      digitalWrite(KeyPin, LOW);  
    } while (0);   // yeah lame, allows break prior though :-)
  }

  delay(50);

  PRNT.println("");
}

void Bluetooth_Check()
{  
  // check for data coming back over Bluetooth
  if(Serial2.available()) {
    char rxVal = Serial2.read();
    if(isControl(rxVal)) {    // "End of Line"
      Command_Interpret(RxLine.Line);
      RxLine.clear();
    }
    else {
      RxLine.append(rxVal);   // append new char to our Rx buffer
    }
  }
}


void Bluetooth_SendFrame(const char* pHdr, const CProtocol& Frame, bool lineterm)
{
  PRNT.print(millis());
  PRNT.print("ms ");
//  DebugReportFrame(pHdr, Frame, lineterm ? "\r\n" : "   ");
  DebugReportFrame(pHdr, Frame, "   ");

  if(digitalRead(HC05_Sense)) {
    if(Frame.verifyCRC()) {
      // send data frame to HC-05
      Serial2.print(pHdr);
      Serial2.write(Frame.Data, 24);
      // toggle LED
      digitalWrite(LED, !digitalRead(LED)); // toggle LED
    }
    else {
      PRNT.print("Bluetooth data not sent, CRC error ");
    }
  }
  else {
    PRNT.print("No Bluetooth client");
      // force LED off
    digitalWrite(LED, 0);
  }
  if(lineterm)
    PRNT.println("");
}

// local function, typically to perform Hayes commands with HC-05
bool Bluetooth_ATCommand(const char* cmd)
{
  Serial2.print(cmd);
  char RxBuffer[16];
  memset(RxBuffer, 0, 16);
  int read = Serial2.readBytesUntil('\n', RxBuffer, 16);  // \n is not included in returned string!
  if((read == 3) && (0 == strcmp(RxBuffer, "OK\r")) ) {
    return true;
  }
  return false;
}

#else // ESP32_USE_HC05
#ifndef ESP32_USE_BLE_RLJ

/////////////////////////////////////////////////////////////////////////////////////////
//                       CLASSIC BLUETOOTH
//                              |
//                              V


#include "BluetoothSerial.h"

BluetoothSerial SerialBT;

void Bluetooth_Init()
{
  RxLine.clear();
  pinMode(LED, OUTPUT);

  if(!SerialBT.begin("ESPHEATER")) {
    PRNT.println("An error occurred initialising Bluetooth");
  }
}

void Bluetooth_Check()
{
  if(SerialBT.available()) {
    char rxVal = SerialBT.read();
    if(isControl(rxVal)) {    // "End of Line"
      Command_Interpret(RxLine.Line);
      RxLine.clear();
    }
    else {
      RxLine.append(rxVal);
    }
  }
}

void Bluetooth_SendFrame(const char* pHdr, const CProtocol& Frame, bool lineterm)
{
  char fullMsg[32];

  PRNT.print(millis());
  DebugReportFrame(pHdr, Frame, lineterm ? "\r\n" : "   ");
  delay(40);
  if(SerialBT.hasClient()) {

    if(Frame.verifyCRC()) {
      digitalWrite(LED, !digitalRead(LED)); // toggle LED
      int len = strlen(pHdr);
      if(len < 8) {
        strcpy(fullMsg, pHdr);
        memcpy(&fullMsg[len], Frame.Data, 24);
        SerialBT.write((uint8_t*)fullMsg, 24+len);
      }
/*      SerialBT.print(pHdr);
      delay(1);
      SerialBT.write(Frame.Data, 24);*/
      delay(10);
    }
    else {
      PRNT.println("Data not sent to Bluetooth, CRC error!");
    }
  }
  else {
    PRNT.println("No Bluetooth client");
    digitalWrite(LED, 0);
  }
}

void Bluetooth_SendACK()
{
 /* if(SerialBT.hasClient()) {
    SerialBT.print("[ACK]");
  }*/
}

 
//                              ^
//                              |
//                       CLASSIC BLUETOOTH
/////////////////////////////////////////////////////////////////////////////////////////

#else // ESP32_USE_BLE_RLJ

/////////////////////////////////////////////////////////////////////////////////////////
//                             BLE
//                              |
//                              V


#include <BLEDevice.h>
#include <BLEServer.h>
#include <BLEUtils.h>
#include <BLE2902.h>

#define SERVICE_UUID           "6E400001-B5A3-F393-E0A9-E50E24DCCA9E" // UART service UUID
#define CHARACTERISTIC_UUID_RX "6E400002-B5A3-F393-E0A9-E50E24DCCA9E"
#define CHARACTERISTIC_UUID_TX "6E400003-B5A3-F393-E0A9-E50E24DCCA9E"

void BLE_Send(std::string Data);

BLEServer *pServer = NULL;
BLECharacteristic* pTxCharacteristic = NULL;
volatile bool deviceConnected = false;
bool oldDeviceConnected = false;

class MyServerCallbacks : public BLEServerCallbacks {

  void onConnect(BLEServer* pServer) {
    deviceConnected = true;
  }

  void onDisconnect(BLEServer* pServer) {
    deviceConnected = false;
  }

};


class MyCallbacks : public BLECharacteristicCallbacks {

  // this callback is called when the ESP WRITE characteristic has been written to by a client
  // We need to *read* the new information!
  void onWrite(BLECharacteristic* pCharacteristic) {

    std::string rxValue = pCharacteristic->getValue();

    while(rxValue.length() > 0) {
      char rxVal = rxValue[0];
      if(isControl(rxVal)) {    // "End of Line"
        Command_Interpret(BluetoothRxLine);
        BluetoothRxLine = "";
      }
      else {
        BluetoothRxLine += rxVal;   // append new char to our Rx buffer
      }
      rxValue.erase(0, 1);
    }
  }

};

void Bluetooth_Init()
{
  // create the BLE device
  BLEDevice::init("DieselHeater");

  // create the BLE server
  pServer = BLEDevice::createServer();
  pServer->setCallbacks(new MyServerCallbacks);

  // create the BLE service
  BLEService *pService = pServer->createService(SERVICE_UUID);

  // create a BLE characteristic
  pTxCharacteristic = pService->createCharacteristic(
    CHARACTERISTIC_UUID_TX,
    BLECharacteristic::PROPERTY_NOTIFY
  );
  pTxCharacteristic->addDescriptor(new BLE2902());


  BLECharacteristic* pRxCharacteristic = pService->createCharacteristic(
    CHARACTERISTIC_UUID_RX,
    BLECharacteristic::PROPERTY_WRITE
  );
  pRxCharacteristic->setCallbacks(new MyCallbacks/*()*/);

  // start the service
  pService->start();
  // start advertising
  pServer->getAdvertising()->start();
  PRNT.println("Awaiting a client to notify...");
}

void Bluetooth_Report(const char* pHdr, const CProtocol& Frame)
{
  if(deviceConnected) {
    if(Frame.verifyCRC()) {
      // BLE can only squirt 20 bytes per packet.
      // build the entire message then divide and conquer
      std::string txData = pHdr;
      txData.append((char*)Frame.Data, 24);
    
      BLE_Send(txData);
    }
  }
}

void Bluetooth_Check()
{
  // disconnecting
  if (!deviceConnected && oldDeviceConnected) {
    delay(500); // give the bluetooth stack the chance to get things ready
    pServer->startAdvertising(); // restart advertising
    PRNT.println("start advertising");
    oldDeviceConnected = deviceConnected;
  }
  // connecting
  if (deviceConnected && !oldDeviceConnected) {
    // do stuff here on connecting
    oldDeviceConnected = deviceConnected;
  }

}

// break down supplied string into 20 byte chunks (or less)
// BLE can only handle 20 bytes per packet!
void BLE_Send(std::string Data)
{
  while(!Data.empty()) {
    std::string substr = Data.substr(0, 20);
    int len = substr.length();    
    pTxCharacteristic->setValue((uint8_t*)Data.data(), len);
    pTxCharacteristic->notify();
    Data.erase(0, len);
  }
}

//                              ^
//                              |
//                             BLE
/////////////////////////////////////////////////////////////////////////////////////////

#endif // ESP32_USE_BLE_RLJ

#endif // ESP32_USE_HC05

#endif  // __ESP32__