#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "RTClib.h"
#include <EEPROM.h>
#include "ZMPT101B.h"
#include <SPI.h>
#include <LoRa.h>
#include <ArduinoJson.h>

#define ss 5
#define rst 25
#define dio0 33

#define EEPROM_SIZE 512
#define PinI 27
#define RelayPin 2
#define UpBtn 12
#define DownBtn 14
bool Screen = true,U=false,D=false,Send=false;
bool Log=false;
int LogTime;
int LastSave =0;
float I=0,V=0;
double P=0;
String Date,Time;

int indx=0, Logindx;
String PowerState;
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
RTC_DS1307 RTC;

DateTime now;
hw_timer_t *My_timer = NULL;
void IRAM_ATTR onTimer(){
  Screen=!Screen;
}
void IRAM_ATTR Up() {
  if(U){
    U=false;
    LogTime=millis();
    if(!Log){
      Logindx=indx-1;
      Log=true;
      display.clearDisplay();
    }else{
      if(Logindx==127){
          Logindx=1;
        }else{
          if(Logindx!=indx-1){
            Logindx++;
          } 
        }
    }
    
  }
  
}
void IRAM_ATTR Down() {
  if(D){
    D=false;
    LogTime=millis();
    if(!Log){
      Logindx=indx-1;
      Log=true;
      display.clearDisplay();
    }else{
      if(Logindx<0){
          Logindx=127;
        }else{
            Logindx--;
        }
    }
    Serial.println(Logindx);
  }
  
}
void setup() {
  Serial.begin(115200);
  EEPROM.begin(EEPROM_SIZE);
  pinMode(UpBtn, INPUT_PULLUP);
  pinMode(DownBtn, INPUT_PULLUP);
  pinMode(RelayPin, OUTPUT);
  attachInterrupt(UpBtn, Up, FALLING);
  attachInterrupt(DownBtn, Down, FALLING);
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  indx=EEPROM.read(511);
  SplashScreen();
  if (!RTC.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }
  RTC.adjust(DateTime(F(__DATE__), F(__TIME__)));
  LoRa.setPins(ss, rst, dio0);
  if (!LoRa.begin(433E6)) {
    Serial.println("Starting LoRa failed!");
    while (1);
  }
  delay(1000);
  My_timer = timerBegin(0, 80, true);
  timerAttachInterrupt(My_timer, &onTimer, true);
  timerAlarmWrite(My_timer, 1000000, true);
  timerAlarmEnable(My_timer); 

  
}

void loop() {
  
  I=getCurrent();
  V=getVoltage();
  P=P*I;
  now = RTC.now();
  Date=GetDate();
  Time=GetTime();
  if(!Log){
    if(Screen){
      SplashScreen1();
    }else{
      SplashScreen2();
    }
  }else{
    LogScreen(Logindx);
  }
  U=true;
  D=true;
  if(millis()-LogTime>5000){
    Log=false;
  }
  if(now.minute()%6==0){
    if(Send){
      for(int i=5;i>=0;i--){
        int k=indx-i;
        if(k<0){
          k=128+k;
        }
        Serial.print(EEPROM.read(k*4));
        Serial.print(":");
        Serial.print(EEPROM.read(k*4+1));
        Serial.print("  P=");
        Serial.print((float)(EEPROM.read(k*4+2)*256+EEPROM.read(k*4+3))/1000);
        Serial.println(" KWh");
      }
      Send=false;
    }
  }else{
    Send=true;
  }
  if(P>5){
    digitalWrite(RelayPin,LOW);
  }
}
int getVoltage(){
  // double  VMax=0;
  // for(int i=0;i<100;i++){
  //   int temp=analogRead(26);
  //   if(VMax<temp){
  //     VMax=temp;
  //   }
  //   delay(1);
  // }
  // double Scale1 = 2 / 4095;
  // double Scale2 = 220.4 / 2;
  // VMax = VMax * 220.4;
  // double VeffD = VMax / sqrt(2);
  // int v = (((VeffD - 420.76) * Scale1) * Scale2) + 210.2;
  //Uncomment this part when sensor is connected
  int v=map(analogRead(26),0,4096,150,260);
  if(v<220){
    PowerState="Voltage Low";
    digitalWrite(RelayPin,LOW);
  }else if(v>240){
    PowerState ="Voltage High";  
    digitalWrite(RelayPin,LOW); 
  }else{
    PowerState="Voltage Normal";
    digitalWrite(RelayPin,HIGH);
  }
  return v;
}
float getCurrent(){
  float result;
  int readValue;                // value read from the sensor
  int maxValue = 0;             // store max value here
  int minValue = 4096;          // store min value here ESP32 ADC resolution
  int mVperAmp = 66;    
   uint32_t start_time = millis();
   while((millis()-start_time) < 100){
       readValue = analogRead(PinI);
       if (readValue > maxValue){
           maxValue = readValue;
       }
       if (readValue < minValue){
           minValue = readValue;
       }
   }
  result = ((maxValue - 2.5) * 3.3)/4096.0;
  //result = ((maxValue - minValue) * 3.3)/4096.0;
  float VRMS = (result/2.0) *0.707;   //root 2 is 0.707
  float AmpsRMS = ((VRMS * 1000)/mVperAmp); //0.3 is the error I got for my sensor
  return AmpsRMS;
}
void SplashScreen(){
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(50, 4); 
  display.println("Smart");
  display.setCursor(14, 20);
  display.println("Electricity Meter");
  display.setCursor(4, 36);
  display.println("Made By");
  display.setCursor(44, 52);
  display.println("IntelliMeters");
  display.display();
}
void SplashScreen1(){
  display.clearDisplay();
  display.setCursor(8, 4);
  display.println(Date+"  "+Time);
  display.setCursor(4, 26);
  display.println("V: "+ String(V,0)+" v  I: "+String((float)I)+" A");
  display.setCursor(4, 36);
  display.println(" ");
  display.setCursor(22, 48);
  display.println(PowerState);
  display.display();
}
void SplashScreen2(){
  display.clearDisplay();
  display.setCursor(8, 4);
  display.println(Date+"  "+Time);
  display.setCursor(8, 26);
  display.println("Power Consumption");
  display.setCursor(32, 48);
  display.println(String((float)I*V/1000)+" KWh");
  //display.setCursor(28, 52);
  //display.println(PowerState);
  display.display();
}
void LogScreen(int i){
  display.clearDisplay();
  display.setCursor(24, 4);
  display.println("Meter Log");
  display.setCursor(8, 20);
  display.println("Power Consumption");
  display.setCursor(28, 36);
  display.println(String((float)(EEPROM.read(i*4+2)*256+EEPROM.read(i*4+3))/1000)+" KWh");
  display.setCursor(4, 52);
  display.print("Time:");
  if(EEPROM.read(i*4)<10){
    display.print("0");
  }
  display.print(String(EEPROM.read(i*4)));
  display.print(":");

  if(EEPROM.read(i*4+1)<10){
    display.print("0");
  }
  display.print(String(EEPROM.read(i*4+1)));
  display.print(" Index:"+ String(i));
  display.display();
}

String GetTime(){
    String str="";
    if (now.hour() < 10){
      str+="0";
    }
    str+=String(now.hour())+":";
    if (now.minute() < 10)
      str+="0";
    str+=String(now.minute());
    if(abs(LastSave-now.minute())>1){
      LastSave=now.minute();
      P=V*I;
      SaveLog(now.hour(),now.minute(),(int)P/256,(int)P%256);
      SendData();
    }
    return str;
}

void SendData(){
  StaticJsonDocument<200> doc;
  doc["Time"] = String(now.hour())+":"+String(now.minute());
  doc["Power"] = V*I;
  String jsonString;
  serializeJson(doc, jsonString);
  
  LoRa.beginPacket();
  LoRa.print(jsonString);
  LoRa.endPacket();
}
String GetDate(){
    String str="";
    if (now.day() < 10){
      str+="0";
    }
    str+=String(now.day())+"/";
    if (now.month() < 10)
      str+="0";
    str+=String(now.month())+"/";;
    if (now.year() < 10)
      str+="0";
    str+=String(now.year());
    return str;
}

void SaveLog(int hr, int mn, int p1, int p2){
    int i=indx;
    i=i*4;
    EEPROM.write(i,hr);
    EEPROM.write(i+1,mn);
    EEPROM.write(i+2,p1);
    EEPROM.write(i+3,p2);
    EEPROM.write(511,indx);
    EEPROM.commit();
    Serial.println("Save at " + String(i) + " "+String(hr)+":"+String(mn)+"  P="+String((float)(p1*256+p2)/1000)+" KWh");
    indx++;
    if(indx>126){
      indx=0;
    }
}