#include <SPI.h>
#include <LoRa.h>
#include "Pangodream_18650_CL.h"
//Libraries for OLED Display
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "img.h"

//define the pins used by the LoRa transceiver module
#define MOSI 27
#define SCK 5
#define SS 18
#define DIO0 26
#define RST 23
#define MISO 19


//923E6 for JAPAN!
#define BAND 923000000

//OLED pins
#define OLED_SDA 21
#define OLED_SCL 22
#define OLED_RST 16
#define SCREEN_WIDTH 128  // OLED display width, in pixels
#define SCREEN_HEIGHT 64  // OLED display height, in pixels

// VARIABLES
boolean buzzer = false;
#define BUTTON_PIN 32
#define BUZZER_PIN 33

//PACKET COUNTER
String Mymessage;
String DecMessage;

//BATTERY
#define ADC_PIN 35
#define CONV_FACTOR 1.8
#define READS 20

Pangodream_18650_CL BL(ADC_PIN, CONV_FACTOR, READS);

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RST);

void setup() {
 //initialize Serial Monitor
  Serial.begin(115200);

  //initialize Button and Buzzer
  pinMode(BUTTON_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  //reset OLED display via software
  pinMode(OLED_RST, OUTPUT);
  digitalWrite(OLED_RST, LOW);
  delay(20);
  digitalWrite(OLED_RST, HIGH);

  //initialize OLED
  Wire.begin(OLED_SDA, OLED_SCL);
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3c, false, false)) {  // Address 0x3C for 128x32
    Serial.println(F("SSD1306 allocation failed"));
    for (;;)
      ;  // Don't proceed, loop forever
  }

  //OPENING DISPLAY
  display.clearDisplay();
  printDisplay(WHITE, 1, 20,20, "LORA SENDER" );
  display.display();
  delay(2000);

  Serial.println("LoRa Sender Test");
  
  //SPI LoRa pins
  SPI.begin(SCK, MISO, MOSI, SS);

  //setup LoRa transceiver module
  LoRa.setPins(SS, RST, DIO0);
  mainDisp();
  //STARTS LORA
  if (!LoRa.begin(BAND)) {
    Serial.println("Starting LoRa failed!");
    //while (1)
    ;
  }
  //LORA SETTINGS
  LoRa.setSpreadingFactor(11);
  LoRa.setSignalBandwidth(500E3);
  LoRa.setCodingRate4(5);
  LoRa.setTxPower(13);
  //ACTIVATE IT TO THE LIBRARY
  //LoRa.setLdoFlag(true);
  Serial.println("LoRa Initializing OK!");
  printDisplay(WHITE, 1, 0,50, "LoRa Initializing OK!" );
  display.display();
  delay(2000);
  clearLine(7);
  clearLine(8);
  display.display();

  Mymessage = "";
  DecMessage = "";
  //BATTERY DISPLAY TASK
  xTaskCreate(battery_info, "battery_info", 2048, NULL, 1, NULL);
}

void loop() {

    //RF MESSAGE IS RECEIVED
  int packetSize = LoRa.parsePacket();
  if (packetSize) {
    getMessage(packetSize);
  }

  //SENDNG CODE
  // turnOff(); delay(5000);

  
  delay(10); // this speeds up the simulation

}


//LCD FUNCTION
void printDisplay(int color, int size, int x, int y, String str) {
  display.setTextColor(color);
  display.setTextSize(size);
  display.setCursor(x, y);
  display.print(str);

}
void mainDisp() {
  display.clearDisplay();
  display.setTextSize(1);
  displayBatInfo();
  printDisplay(WHITE, 2, 0,20, "Buzzer: " );
  printDisplay(WHITE, 2, 90,20, buzzer  ? "ON" : "OFF" );
  display.display();
}

void clearLine(int i) {
  int e = i * 8;
  int s = e - 8;

  for (int i = s; i < e; i++) {
    for (int j = 0; j < 128; j++) {
      display.drawPixel(j, i, BLACK);
    }
  }
}





//GET MESSAGE PACKETS
void getMessage(int packetSize) {
  // received a packet
  Serial.print("Received packet '");
  Serial.println(packetSize);
  byte packet[packetSize];
  int id = 0;
  Mymessage = "";

  // read packet
  while (LoRa.available()) {
    byte data = LoRa.read();
    Mymessage = data + " ";
    packet[id] = data;
    id++;

    Serial.print("0x");
    Serial.print((char)data, HEX);
    Serial.print(" ");


  }
  // print RSSI of packet
  Serial.print("' with RSSI ");
  Serial.println(LoRa.packetRssi());

  if (!buzzer && DecodeReceived(packet) == "BUZZON") {
    buzzer = true;
    mainDisp();

  } else if (buzzer && DecodeReceived(packet) == "BUZZOFF") {
    buzzer = false;
    mainDisp();
  }



}


//DECODING FUNCTIONS
String DecodeReceived(byte data[]) {
  //byte data[] = {0x44, 0x19, 0x0, 0x5, 0xE5, 0xF4, 0xE2, 0xE5, 0xFE };
  //Message Size
  int size = (int)data[0] - 64;
  Serial.print("Size: ");
  Serial.print(size);
  //Channel
  Serial.print(" Channel: ");
  Serial.print(data[1], HEX);
  Serial.println(" No: " + String(data[1]) + " Freq: " + ((int)data[1] + 862) + " Mhz");
  //Address
  Serial.print("Address: ");
  Serial.print(String(data[2]) + " " + String(data[3]));
  //key
  Serial.print(" Key: ");
  Serial.print(getCDEByteKey(data[1]), HEX);
  byte deckey = getCDEByteKey(data[1]);
  //Main Message
  Serial.print(" Message: ");
  String Message = "";
  for (int i = 4; i < (4 + size); i++) {
    Message = Message + (char)(data[i] ^ deckey);
  }
  Serial.print(Message);
  Serial.print(" Checksum: ");
  Serial.println(checksum(data, sizeof(data) - 1) == (uint8_t)data[sizeof(data) - 1] ? "Match" : "Not Match");
  delay(10000);

  return Message;

}
static uint8_t getCDEByteKey(const uint8_t _channelNo) {
  const uint8_t keyLUT[] = {0x0A, 0x09, 0x08, 0x0F, 0x0E, 0x0D, 0x0C, 0x03, 0x02, 0x01, 0x00, 0x07, 0x06, 0x05, 0x04, 0x0B};
  return ((_channelNo + 0x99) & 0xF0) |  keyLUT[_channelNo & 0x0F];
}

uint8_t checksum(uint8_t* buf, uint8_t s) {
  uint32_t sum = 0;
  for (uint8_t i = 0; i < s; ++i) {
    sum += buf[i];
  }
  sum = 0x100 - (sum & 0xFF);
  return (uint8_t)sum;
}

//SENDING MESSAGE FUNCTION
void turnOff() {
  //CREATE THE MESSAGE
  uint8_t     radioBuffer[12]   = {0};
  radioBuffer[0] = 0x40 + 7;  //Message size
  radioBuffer[1] = 0x3D;      //Channel
  radioBuffer[2] = 0x00;      //Address
  radioBuffer[3] = 0x00;      //Address
  sprintf((char*)&radioBuffer[4], "BUZZOFF");

  uint8_t key = getCDEByteKey(radioBuffer[1]);

  //ENCRYPT THE MESSAGE PART
  //encode data with the key
  for (uint8_t i = 4; i < 11; ++i) {
    radioBuffer[i] = radioBuffer[i] ^ key;
  }

  //compute checksum
  radioBuffer[11] = checksum(radioBuffer, 11);

  //PRINTS THE PACKET DATA
  for (uint8_t i = 0; i < 12; ++i) {
    Serial.print("0x");
    if (radioBuffer[i] < 0x10)  Serial.print("0");
    Serial.print(radioBuffer[i], HEX);
    Serial.print(" ");
  }
  Serial.println();

  //SENDS THE DATA
  LoRa.beginPacket();
  LoRa.write(radioBuffer, 12);
  LoRa.endPacket();
}


//BATTERY INFO FUNCTIONS
void battery_info(void *arg)
{
  while (1) {
    Serial.println("");
    Serial.print("Average value from pin: ");
    Serial.println(BL.pinRead());
    Serial.print("Volts: ");
    Serial.println(BL.getBatteryVolts());
    Serial.print("Charge level: ");
    Serial.println(BL.getBatteryChargeLevel());
    Serial.print("Reading: ");
    Serial.println(analogRead(35));

    if (BL.getBatteryVolts() >= 3.2) {
      clearLine(1);      
      printDisplay(WHITE, 1, 100,1, String(BL.getBatteryChargeLevel())+"%");
      display.drawBitmap(80, 0, BATTERY_BOX0, 128, 64, BLACK);
      display.drawBitmap(80, 0, BATTERY_BOX3, 128, 64, WHITE);
      display.display();
      vTaskDelay(500);
      display.drawBitmap(80, 0, BATTERY_BOX3, 128, 64, BLACK);
      display.drawBitmap(80, 0, BATTERY_BOX2, 128, 64, WHITE);
      display.display();
      vTaskDelay(500);
      display.drawBitmap(80, 0, BATTERY_BOX2, 128, 64, BLACK);
      display.drawBitmap(80, 0, BATTERY_BOX1, 128, 64, WHITE);
      display.display();
      vTaskDelay(500);
      display.drawBitmap(80, 0, BATTERY_BOX1, 128, 64, BLACK);
      display.drawBitmap(80, 0, BATTERY_BOX0, 128, 64, WHITE);
      display.display();
      vTaskDelay(500);

    } else {
      displayBatInfo();
      vTaskDelay(1000);
    }

  }

}
void displayBatInfo() {
  clearLine(1);
  int batteryLevel = BL.getBatteryChargeLevel();
  if (batteryLevel >= 67) {
    display.drawBitmap(80, 0, BATTERY_BOX1, 128, 64, WHITE);
  } else if (batteryLevel < 66 && batteryLevel >= 33 ) {
    display.drawBitmap(80, 0, BATTERY_BOX2, 128, 64, WHITE);
  } else if (batteryLevel < 32 && batteryLevel >= 10 ) {
    display.drawBitmap(80, 0, BATTERY_BOX3, 128, 64, WHITE);
  } else {
    display.drawBitmap(80, 0, BATTERY_BOX0, 128, 64, WHITE);
  }
  printDisplay(WHITE, 1, 100,1, String(BL.getBatteryChargeLevel())+"%");
  display.display();
}