#include <Arduino.h>
#include <U8g2lib.h>
#include <Wire.h>
#include <ESP32Time.h>
#include <string.h>
#include <EEPROM.h>

U8G2_SH1106_128X32_VISIONOX_1_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE); 

#define EEPROM_SIZE 16

#define encoderclkPin 15
#define encoderdtPin 16
#define encoderswPin 17
#define timerOutPin 2

#define timeDisplayState 0
#define timeSettingState 1
#define timerOnSettingState 2
#define timerOffSettingState 3

#define timeDisplay 0
#define timerOn 1
#define timerOff 2


#define hourEditState 0
#define minuteEditState 1
#define secondEditState 2
 
int timeEditState = hourEditState;
int activeState = timeDisplayState;
int encoderCounter = 0; 
int encoderState;
bool encoderSwitchPressed = false;
int encoderSwitchState = HIGH;
int encoderSwitchDownCounter = 0;
int encoderSwitchUpCounter = 0;
bool blinky = false;

int setTimeHour;
int setTimeMinute;

bool timerState = false;
int timerOnHour = 15;
int timerOnMinute = 20;
int timerOffHour = 0;
int timerOffMinute = 0;
bool initialEdit = true;

int lastClk = HIGH;

//ESP32Time rtc;
ESP32Time rtc(0);  

void IRAM_ATTR readEncoder() {
  encoderSwitchUpCounter = 0;
  int dtValue = digitalRead(encoderdtPin);
  if (dtValue == HIGH) {
    encoderCounter++;
  }
  if (dtValue == LOW) {
    encoderCounter--;
  }
}
void IRAM_ATTR encoderswPinDown () {
  encoderSwitchPressed = true;
  encoderSwitchDownCounter = 0;
  encoderSwitchUpCounter = 0;
}

void EEPROM_Save() {
  EEPROM.write(0, timerOnHour);
  EEPROM.write(1, timerOnMinute);
  EEPROM.write(2, timerOffHour);
  EEPROM.write(3, timerOffMinute); 
}


void EEPROM_Load() {
  EEPROM.write(0, timerOnHour);
  EEPROM.write(1, timerOnMinute);
  EEPROM.write(2, timerOffHour);
  EEPROM.write(3, timerOffMinute);
}


void initSettingState() {
  if (activeState == timeSettingState) {
    setTimeHour = rtc.getHour(true);
    setTimeMinute = rtc.getMinute();
  } else if (activeState == timerOnSettingState) {
    setTimeHour = timerOnHour;
    setTimeMinute = timerOnMinute;
  } else if (activeState == timerOffSettingState) {
    setTimeHour = timerOffHour;
    setTimeMinute = timerOffMinute;
  }
  timeEditState = hourEditState;
  encoderSwitchPressed = false;
  encoderSwitchDownCounter = 0;
  encoderSwitchUpCounter = 0;
}

void checkAndSetTimerOutput() {

  int currentTotalMinutes;
  int timerOnTotalMinutes;
  int timerOffTotalMinutes;

  currentTotalMinutes = (60*rtc.getHour(true)) + rtc.getMinute();
  timerOnTotalMinutes = (60*timerOnHour) + timerOnMinute;
  timerOffTotalMinutes = (60*timerOffHour) + timerOffMinute;

  bool checkTimer = false;
// if timer has been set and isn't same:
  if (timerOnTotalMinutes != timerOffTotalMinutes) {
// if timer-on is "after" timer-off:
    if (timerOnTotalMinutes > timerOffTotalMinutes) {
// if current time is after timer-on or before timer-off
      if ((currentTotalMinutes >= timerOnTotalMinutes) || (currentTotalMinutes < timerOffTotalMinutes)) {
          checkTimer = true;
      }
    } else {
// if timer-on is "before" timer-off:
// if current time is after timer-on and before timer-off
      if ((currentTotalMinutes >= timerOnTotalMinutes) && (currentTotalMinutes < timerOffTotalMinutes)) {
          checkTimer = true;
      }

    }
  }
  if (checkTimer == true) {
    timerState = true;
    digitalWrite(timerOutPin, HIGH); 
  }else {
    timerState = false;
    digitalWrite(timerOutPin, LOW);
  }
}

void setup() {
  pinMode(timerOutPin, OUTPUT);
  digitalWrite(timerOutPin, LOW);
  pinMode(encoderswPin, INPUT_PULLUP);
  pinMode(encoderclkPin, INPUT);
  pinMode(encoderdtPin, INPUT);
  attachInterrupt(digitalPinToInterrupt(encoderclkPin), readEncoder, FALLING);
  attachInterrupt(digitalPinToInterrupt(encoderswPin), encoderswPinDown, FALLING);


  Serial.begin(115200);
  u8g2.begin();  

  rtc.setTime(30, 24, 15, 17, 11, 2022);  // 17th Nov 2022 15:24:30
  EEPROM.begin(EEPROM_SIZE);
  EEPROM_Load();
}





void drawTime(int activeState, bool blinky) {
  u8g2.firstPage();
  do {
    u8g2.setFont(u8g2_font_t0_13b_mr);
    u8g2.setCursor(0,10);
    if (activeState == timeDisplayState) {
      u8g2.print("Pa:");
      u8g2.drawBox(10,0,2,2);
      if (timerState == false) {
        u8g2.drawCircle(8,18,5,U8G2_DRAW_UPPER_LEFT|U8G2_DRAW_UPPER_RIGHT);
        u8g2.drawEllipse(8,19,5,6,U8G2_DRAW_LOWER_LEFT|U8G2_DRAW_LOWER_RIGHT);
      }
      if (timerState == true) {
        u8g2.drawDisc(8,18,5,U8G2_DRAW_UPPER_LEFT|U8G2_DRAW_UPPER_RIGHT);
        u8g2.drawFilledEllipse(8,19,5,6,U8G2_DRAW_LOWER_LEFT|U8G2_DRAW_LOWER_RIGHT);
      }
      u8g2.drawLine(6,25,6,30);
      u8g2.drawLine(10,25,10,30);
      u8g2.drawLine(7,29,9,29);
      u8g2.drawLine(7,27,9,27);
      u8g2.drawLine(7,31,9,31);
      u8g2.drawLine(6,25,6,30);
      u8g2.drawLine(10,25,10,30);

      u8g2.drawLine(7,29,9,29);
      u8g2.drawLine(7,27,9,27);

      u8g2.drawLine(7,31,9,31);

      u8g2.setCursor(36,10);
      if (timerOnHour <= 9) u8g2.print("0");
      u8g2.print(timerOnHour);
      u8g2.print(":");
      if (timerOnMinute <= 9) u8g2.print("0");
      u8g2.print(timerOnMinute);
      u8g2.setCursor(74,10);
      u8g2.print("-");
      u8g2.setCursor(83,10);
      if (timerOffHour <= 9) u8g2.print("0");
      u8g2.print(timerOffHour);
      u8g2.print(":");
      if (timerOffMinute <= 9) u8g2.print("0");
      u8g2.print(timerOffMinute);

    }
    if (activeState == timeSettingState) {
      u8g2.setCursor(0,12);
      u8g2.print("Ange");
      u8g2.setCursor(0,28);
      u8g2.print("tid:");
    }

    if (activeState == timerOnSettingState) {
      u8g2.setCursor(0,12);
      u8g2.print("Timer");
      u8g2.setCursor(0,28);
      u8g2.print("pa:");
      u8g2.drawBox(10,18,2,2);

    }
    if (activeState == timerOffSettingState) {
      u8g2.setCursor(0,12);
      u8g2.print("Timer");
      u8g2.setCursor(0,28);
      u8g2.print("av:");
    }
    u8g2.setFont(u8g2_font_VCR_OSD_mr);
    u8g2.drawBox(62,17,2,2);
    u8g2.drawBox(62,25,2,2);
    u8g2.drawBox(92,17,2,2);
    u8g2.drawBox(92,25,2,2);

    u8g2.setCursor(36,30);

//  Time display:
    if (activeState == timeDisplayState) {
      if (rtc.getHour(true) <= 9) u8g2.print("0");
      u8g2.print(rtc.getHour(true));
      u8g2.setCursor(66,30);
      if (rtc.getMinute() <= 9) u8g2.print("0");
      u8g2.print(rtc.getMinute());
      u8g2.setCursor(96,30);
      if (rtc.getSecond() <= 9) u8g2.print("0");
      u8g2.print(rtc.getSecond());
    } else {

      if ((blinky == true) && (timeEditState == hourEditState)) {
        u8g2.print("  "); 
      } else {
        if (setTimeHour <= 9) u8g2.print("0");
        u8g2.print(setTimeHour);
      }
      u8g2.setCursor(66,30);
      if ((blinky == true) && (timeEditState == minuteEditState)) {
        u8g2.print("  "); 
      } else {
        if (setTimeMinute <= 9) u8g2.print("0");
        u8g2.print(setTimeMinute);
      }
      u8g2.setCursor(96,30);
      if (activeState == timeSettingState) {
        if (rtc.getSecond() <= 9) u8g2.print("0");
        u8g2.print(rtc.getSecond());
      } else {
        u8g2.print("00");
      }
    } 
  } while ( u8g2.nextPage() );
}


void loop() {

//  Read encoder:
    encoderSwitchState = digitalRead(encoderswPin);
    if (encoderSwitchState == LOW)  encoderSwitchDownCounter++;
    if (encoderSwitchState == HIGH) encoderSwitchUpCounter++;

//  Change program state when switch pressed down:
  if (encoderSwitchDownCounter >= 2) {
    if (activeState == timeSettingState) 
      rtc.setTime(rtc.getSecond(), setTimeMinute, setTimeHour, rtc.getDay(), rtc.getMonth(), rtc.getYear());  // 17th Nov 2022 15:24:30
    if (activeState == timerOnSettingState) {
      timerOnHour = setTimeHour;
      timerOnMinute = setTimeMinute;
    }
    if (activeState == timerOffSettingState) {
      timerOffHour = setTimeHour;
      timerOffMinute = setTimeMinute;
    }
    activeState +=1 ;
    if (activeState > timerOffSettingState) activeState = timeSettingState;
    initSettingState();
  }

//  return to timeDisplayState after timeout:
  if (encoderSwitchUpCounter > 10) {
    encoderSwitchUpCounter = 0;
    if (activeState == timeSettingState) 
      rtc.setTime(rtc.getSecond(), setTimeMinute, setTimeHour, rtc.getDay(), rtc.getMonth(), rtc.getYear());  // 17th Nov 2022 15:24:30
    if (activeState == timerOnSettingState) {
      timerOnHour = setTimeHour;
      timerOnMinute = setTimeMinute;
    }
    if (activeState == timerOffSettingState) {
      timerOffHour = setTimeHour;
      timerOffMinute = setTimeMinute;
    } 
    EEPROM_Save();
    activeState = timeDisplayState;
  }



  if (activeState == timeDisplayState) {
    drawTime(activeState,false);
    delay(825); 
  } else {
    if (encoderSwitchPressed == true)  {
      encoderSwitchPressed = false;
      if (timeEditState == hourEditState) timeEditState = minuteEditState;
        else timeEditState = hourEditState;
    }
    if (timeEditState == hourEditState) {
      if (encoderCounter != 0) {
        setTimeHour = setTimeHour + encoderCounter;
        encoderCounter = 0;
        if (setTimeHour <= 0) setTimeHour = 23;
        if (setTimeHour >= 24) setTimeHour = 0;
      }  
    }
    if (timeEditState == minuteEditState) {
      if (encoderCounter != 0) {
        setTimeMinute = setTimeMinute + encoderCounter;
        encoderCounter = 0;
        if (setTimeMinute < 0) setTimeMinute = 59;
        if (setTimeMinute > 59) setTimeMinute = 0;
      }
    }
    drawTime(activeState,blinky);
    blinky = !blinky;
    delay(500);
  }
  checkAndSetTimerOutput();


//  struct tm timeinfo = rtc.getTimeStruct();
  //Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S");   //  (tm struct) Sunday, January 17 2021 07:24:38
  

}