#include <LiquidCrystal.h>

const int rs = 8;   // Pin 7  on Arduino to pin 4  (RS) on LCD
const int en = 7;   // Pin 6  on Arduino to pin 6  (E)  on LCD
const int d4 = 6;  // Pin 12 on Arduino to pin 11 (D4) on LCD
const int d5 = 5;  // Pin 10 on Arduino to pin 12 (D5) on LCD
const int d6 = 4;   // Pin 9  on Arduino to pin 13 (D6) on LCD
const int d7 = 3;   // Pin 8  on Arduino to pin 14 (D7) on LCD

LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

// Temp Sensor reference: https://docs.wokwi.com/parts/wokwi-ntc-temperature-sensor
const float BETA = 3950;
const int tempMin = 1; // Celcius
const int tempMax = 20; // Celcius
const int timeTecPause = 10; // Seconds

int timerMs = 0;
int timer = 0;

int lcdMode = 0; // 0 = Off, 1 = Boot, 2 = Run, 3 = Shutdown
int lcdTimerMs = 0;
char *lcdStringMode[] = {"Off", "Cool", "Heat"};

int pinButtonRed = 11;
int pinButtonGreen = 10;
int pinButtonBlue = 9;
int pinSensorTemp = A0;
int pinRelayCool = A2;
int pinRelayHeat = A1;
int pinBuzzer = 12;
int pinLcdBacklight = 2;

int buttonRed = 0;
int buttonGreen = 0;
int buttonBlue = 0;

int state = 0; // 0 = Off, 1 = Run
int mode = 0; // 0 = Off, 1 = Cooling, 2 = Heating(NOT WORKING)
int tecState = 0; // 0 = Off, -1 = Cooling, 1 = Heating

int sensorVal = 0;
int sensorTemp = 0;

int setTemp = 0;
int setTempCoolMin = 1;
int setTempCoolMax = 25;
int setTempHeatMin = 25;
int setTempHeatMax = 50;

// LCD CUSTOM CHARACTER
byte testChar[8] = {
  0b11111,
  0b11111,
  0b11111,
  0b11111,
  0b11111,
  0b11111,
  0b11111,
  0b11111
};

byte celciusChar[8] = {
  0b11000,
  0b11000,
  0b00111,
  0b01000,
  0b01000,
  0b01000,
  0b01000,
  0b00111
};

byte thermometerChar[8] = {
  0b00100,
  0b01010,
  0b01010,
  0b01110,
  0b01110,
  0b11111,
  0b11111,
  0b01110
};

byte fanChar[8] = {
  0b00000,
  0b01000,
  0b00101,
  0b01110,
  0b10100,
  0b00010,
  0b00000,
  0b00000
};
// END

void lcdTest() {
  // LCD
  digitalWrite(pinLcdBacklight, HIGH);
  lcd.display();
  lcd.clear();
  for(int i = 0; i < 2; i++) {
    for(int j = 0; j < 16; j++) {
      lcd.setCursor(j, i);
      lcd.write(byte(0));
      //delay(25);
    }
  }
  delay(500);
  digitalWrite(pinLcdBacklight, LOW);
  lcd.clear();
  lcd.noDisplay();
  //lcd.write(byte(1));
  //delay(1000);
}

void lcdDisplay(int currentMode, int setTemp, int sensorTemp) {
  // LCD
  if (lcdMode == 0) {
    lcd.noDisplay();
    if (currentMode > 0) {
      digitalWrite(pinLcdBacklight, HIGH);
      lcd.display();
      lcdMode++;
    }
  } else if (lcdMode == 1) {
    if (lcdTimerMs == 0) {
      lcd.clear();
      lcd.setCursor(3, 0);
      lcd.print("");
      lcd.setCursor(0, 1);
      lcd.print("Power on...");
      lcdTimerMs++;
    } else if (lcdTimerMs < 10) {
      lcdTimerMs++;
    } else if (lcdTimerMs == 10) {
      for(int i = 0; i < 2; i++) {
        for(int j = 0; j < 16; j++) {
          lcd.setCursor(j, i);
          lcd.write(byte(0));
          delay(16);
        }
      }
      for(int i = 0; i < 2; i++) {
        for(int j = 0; j < 16; j++) {
          lcd.setCursor(j, i);
          lcd.print(" ");
          delay(16);
        }
      }
      lcd.clear();
      lcdTimerMs = 0;
      lcdMode++;
    }
  } else if (lcdMode == 2) {
    if (currentMode < 1) {
      lcdMode++;
    } else {
      lcd.setCursor(0, 0);
      lcd.print(lcdStringMode[mode]);

      lcd.setCursor(9, 0);
      lcd.print("Set:");

      lcd.setCursor(13, 0);
      if (setTemp >= 10) {
        lcd.print(setTemp);
        lcd.write(1);
      } else {
        lcd.print(" ");
        lcd.print(setTemp);
        lcd.write(byte(1));
      }
      //lcd.print(setTemp);
      //lcd.write(byte(1));

      lcd.setCursor(0, 1);
      lcd.write(2);
      //lcd.print("Temp:");

      lcd.setCursor(1, 1);
      //lcd.setCursor(5, 1);
      if (sensorTemp >= 10) {
        lcd.print(" ");
        lcd.print(sensorTemp);
        lcd.write(byte(1));
      } else if (sensorTemp >= 0) {
        lcd.print("  ");
        lcd.print(sensorTemp);
        lcd.write(byte(1));
      } else if (sensorTemp > -10) {
        lcd.print(" ");
        lcd.print(sensorTemp);
        lcd.write(byte(1));
      } else {
        lcd.print(sensorTemp);
        lcd.write(byte(1));
      }

      if (tecState == 0) {
        lcd.setCursor(15, 1);
        lcd.print(" ");
      } else {
        lcd.setCursor(15, 1);
        lcd.write(3);
      }
    }

  } else if (lcdMode == 3) {
    if (lcdTimerMs == 0) {
      for(int i = 0; i < 2; i++) {
        for(int j = 0; j < 16; j++) {
          lcd.setCursor(j, i);
          lcd.write(byte(0));
          delay(16);
        }
      }
      for(int i = 0; i < 2; i++) {
        for(int j = 0; j < 16; j++) {
          lcd.setCursor(j, i);
          lcd.print(" ");
          delay(16);
        }
      }
      //lcd.clear();
      lcd.setCursor(3, 0);
      lcd.print("");
      lcd.setCursor(0, 1);
      lcd.print("Power off...");
      lcdTimerMs++;
    } else if (lcdTimerMs < 10) {
      lcdTimerMs++;
    } else if (lcdTimerMs == 10) {
      for(int i = 0; i < 2; i++) {
        for(int j = 0; j < 16; j++) {
          lcd.setCursor(j, i);
          lcd.write(byte(0));
          delay(16);
        }
      }
      for(int i = 0; i < 2; i++) {
        for(int j = 0; j < 16; j++) {
          lcd.setCursor(j, i);
          lcd.print(" ");
          delay(16);
        }
      }
      lcd.clear();
      lcd.noDisplay();
      digitalWrite(pinLcdBacklight, LOW);
      lcdTimerMs = 0;
      lcdMode = 0;
    }
  }
}

int toggleMode(int currentMode) {
  if (currentMode == 0) {
    return currentMode;
  } else if (currentMode == 1) {
    if (mode == 0) {
      return currentMode;
    } else {
      return ++currentMode;
    }
  } else {
    return --currentMode;
  }
}

void buzzerBeep(int beepType) {
  if (beepType == 1) {
    // Short beep
    tone(pinBuzzer, 1000, 10);
  } else if (beepType == 2) {
    // Power up beep
    tone(pinBuzzer, 1000, 50);
    delay(75);
    tone(pinBuzzer, 1200, 50);
    delay(75);
    tone(pinBuzzer, 1600, 50);
    delay(75);
    tone(pinBuzzer, 2000, 100);
  } else if (beepType == 3) {
    // Power off beep...
    tone(pinBuzzer, 2000, 100);
    delay(75);
    tone(pinBuzzer, 1600, 50);
    delay(75);
    tone(pinBuzzer, 1200, 50);
    delay(75);
    tone(pinBuzzer, 1000, 50);
  } else if (beepType == 4) {
    // Mode beep
    tone(pinBuzzer, 1000, 100);
    //tone(pinBuzzer, 1000, 50);
    //delay(150);
    //tone(pinBuzzer, 1000, 50);
  }
}

void setup() {
  // put your setup code here, to run once:
  pinMode(pinButtonRed, INPUT_PULLUP);
  pinMode(pinButtonGreen, INPUT_PULLUP);
  pinMode(pinButtonBlue, INPUT_PULLUP);
  buttonRed = digitalRead(pinButtonRed);
  buttonGreen = digitalRead(pinButtonGreen);
  buttonBlue = digitalRead(pinButtonBlue);

  pinMode(pinRelayCool, OUTPUT);
  digitalWrite(pinRelayCool, LOW);
  pinMode(pinRelayHeat, OUTPUT);
  digitalWrite(pinRelayHeat, LOW);

  pinMode(pinBuzzer, OUTPUT);
  pinMode(pinLcdBacklight, OUTPUT);

  lcd.begin(16, 2);
  lcd.createChar(0, testChar);
  lcd.createChar(1, celciusChar);
  lcd.createChar(2, thermometerChar);
  lcd.createChar(3, fanChar);

  state = 0;
  mode = 0;
  tecState = 0;
  lcdMode = 0;
  lcdTimerMs = 0;
  timerMs = 0;
  timer = 0;

  setTemp = 15;

  lcdTest();
  buzzerBeep(1);
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(100);

  buttonRed = digitalRead(pinButtonRed);
  buttonGreen = digitalRead(pinButtonGreen);
  buttonBlue = digitalRead(pinButtonBlue);

  sensorVal = analogRead(A0);
  sensorTemp = 1 / (log(1 / (1023. / sensorVal - 1)) / BETA + 1.0 / 298.15) - 273.15;
  //int sensorTempInt = static_cast<int>(sensorTemp);

  // Buttons
  if (buttonRed == 0) {
    if (state != 0) {
      if (mode == 1) {
        if (setTemp < setTempCoolMax) {
          setTemp++;
          buzzerBeep(1);
        }
      } else if (mode == 2) {
        if (setTemp < setTempHeatMax) {
          setTemp++;
          buzzerBeep(1);
        }
      }
    }
  } else {
    if (state != 0) {
      if (mode == 1) {
        if (setTemp > setTempCoolMax) {
          setTemp--;
        }
      } else if (mode == 2) {
        if (setTemp > setTempHeatMax) {
          setTemp--;
        }
      }
    }
  }
  
  if (buttonGreen == 0 && timerMs < 10) {
    if (timerMs < 10) {
      timerMs++;
    } else {
      timerMs = 0;
    }
  } else {
    if (state == 1) {
      if (timerMs == 10) {
        // Power off
        state = 0;
        mode = toggleMode(state);
        timerMs = 0;
        buzzerBeep(3);
      } else if (timerMs > 1) {
        // Change modes
        mode = toggleMode(mode);
        timerMs = 0;
        buzzerBeep(4);
      }
    } else {
      if (timerMs == 10) {
        // Power on
        state = 1;
        mode = toggleMode(state);
        timerMs = 0;
        buzzerBeep(2);
      } else {
        timerMs = 0;
      }
    }
    //timerMs = 0;
    //timer = 0;
  }

  if (buttonBlue == 0) {
    if (state != 0) {
      if (mode == 1) {
        if (setTemp > setTempCoolMin) {
          setTemp--;
          buzzerBeep(1);
        }
      } else if (mode == 2) {
        if (setTemp > setTempHeatMin) {
          setTemp--;
          buzzerBeep(1);
        }
      }
    }
  } else {
    if (state != 0) {
      if (mode == 1) {
        if (setTemp < setTempCoolMin) {
          setTemp++;
        }
      } else if (mode == 2) {
        if (setTemp < setTempHeatMin) {
          setTemp++;
        }
      }
    }}

  // TEC relay decision
  if (mode == 1) {
    if (sensorTemp > setTemp + 1) {
      tecState = -1;
    } else if (sensorTemp <= setTemp) {
      tecState = 0;
    }
  } else if (mode == 2) {
    if (sensorTemp < setTemp - 1) {
      tecState = 1;
    } else if (sensorTemp >= setTemp) {
      tecState = 0;
    }
  } else {
    tecState = 0;
  }

  // Set relay
  if (tecState == 1) {
    digitalWrite(pinRelayCool, LOW);
    digitalWrite(pinRelayHeat, HIGH);
  } else if (tecState == -1) {
    digitalWrite(pinRelayCool, HIGH);
    digitalWrite(pinRelayHeat, LOW);
  } else {
    digitalWrite(pinRelayCool, LOW);
    digitalWrite(pinRelayHeat, LOW);
  }

  //lcdDisplay(lcdStringMode[mode], setTemp, sensorTemp);
  lcdDisplay(mode, setTemp, sensorTemp);
}