#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// Pin definitions
const int relayPin = 10;             
const int lowerSensorPin = 8;        
const int upperSensorPin = 9;        
const int thirdSensorPin = 5;        
const int specialPin = 13;           
const int buzzerPin = 12;            
const int pin6 = 6;                  
const int resetButtonPin = 11;       
const int modeSwitchPin = 7;         
const int manualControlPin = 4;      

// OLED display setup
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Variables
bool motorState = false;
unsigned long motorOffTime = 0;      
unsigned long buzzerStartTime = 0;   
bool buzzerActive = false;           
unsigned long motorOnTime = 0;       
unsigned long pin6LowTime = 0;       
bool dryRun = false;                 
bool resetRequired = false;          
bool manualMotorState = false;       
bool lastAutoMode = false;           
unsigned long autoModeOffTime = 0;   
bool autoModeOffTimerSet = false;    
unsigned long lastBlinkTime = 0;     // Track the last time "Low" was shown
bool blinkState = false;             // Track the blink state

void setup() {
  pinMode(relayPin, OUTPUT);
  pinMode(lowerSensorPin, INPUT); 
  pinMode(upperSensorPin, INPUT); 
  pinMode(thirdSensorPin, INPUT); 

  pinMode(specialPin, INPUT);     
  pinMode(buzzerPin, OUTPUT);     
  pinMode(pin6, INPUT);           
  pinMode(resetButtonPin, INPUT_PULLUP); 
  pinMode(modeSwitchPin, INPUT_PULLUP);  
  pinMode(manualControlPin, INPUT_PULLUP); 

  digitalWrite(relayPin, LOW);    
  digitalWrite(buzzerPin, LOW);   

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 initialization failed!"));
    for (;;);
  }

  // Custom Splash Screen
  display.clearDisplay();
  display.setTextSize(2); 
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(21, 20); 
  display.println("KAYYALA"); 

  display.setTextSize(1); 
  display.setCursor(10, 40); 
  display.println("Water Level System"); 

  display.display();
  delay(7000);

  display.clearDisplay(); 
}

void loop() {
  // Read sensor and pin states
  bool lowerSensor = digitalRead(lowerSensorPin);
  bool upperSensor = digitalRead(upperSensorPin);
  bool thirdSensor = digitalRead(thirdSensorPin); 
  bool specialCondition = digitalRead(specialPin);
  bool pin6State = digitalRead(pin6);
  bool resetButton = digitalRead(resetButtonPin);
  bool autoMode = !digitalRead(modeSwitchPin);
  bool manualControlButton = digitalRead(manualControlPin) == LOW;

  // Turn motor OFF and reset manual motor state if any mode change occurs
  if (lastAutoMode != autoMode) {
    motorState = false;
    manualMotorState = false;
    autoModeOffTimerSet = false;
  }
  lastAutoMode = autoMode;

  // Reset condition: clear dry run flag and reset motor state
  if (resetButton == LOW) {
    dryRun = false;
    resetRequired = false;
    motorState = false;
    digitalWrite(relayPin, LOW);
    digitalWrite(buzzerPin, LOW);
    buzzerActive = false;
    delay(500);
  }

  if (dryRun) {
    // If dry run is active, disable the Auto/Manual switch
    digitalWrite(relayPin, LOW);
    if (!buzzerActive) {
      buzzerStartTime = millis();
      buzzerActive = true;
      digitalWrite(buzzerPin, HIGH);
    }
    if (millis() - buzzerStartTime >= 3000) {
      digitalWrite(buzzerPin, LOW);
      buzzerActive = false;
    }
  } else if (autoMode && !resetRequired) {
    // Automatic mode
    if (specialCondition == HIGH) {
      motorOffTime = millis() + 50000; 
      motorState = false; 
    } else if (millis() < motorOffTime) {
      motorState = false;
    } else if (lowerSensor == LOW) {
      if (!motorState) {
        motorState = true;  
        motorOnTime = millis();
        pin6LowTime = millis();
        dryRun = false;
        beepBuzzer(3);
      }
    } else if (lowerSensor == HIGH && upperSensor == HIGH) {
      if (!autoModeOffTimerSet) {
        autoModeOffTime = millis() + 5000;
        autoModeOffTimerSet = true;
      } else if (millis() >= autoModeOffTime) {
        motorState = false;
      }
    } else {
      autoModeOffTimerSet = false;
    }

    if (manualControlButton && lowerSensor == HIGH && upperSensor == LOW) {
      motorState = true;  
      pin6LowTime = millis(); 
      beepBuzzer(3);
    }

    if (motorState && pin6State == LOW && millis() - pin6LowTime >= 50000) {
      motorState = false;
      dryRun = true;
      resetRequired = true;
      buzzerStartTime = millis();
      buzzerActive = true;
    } else if (motorState && pin6State == HIGH) {
      pin6LowTime = millis();
    }
  } else if (!autoMode) {
    // Manual mode
    if (manualControlButton) {
      manualMotorState = !manualMotorState;
      delay(1000);
    }
    motorState = manualMotorState;
    dryRun = false;

    // Blinking "Low" condition
    if (lowerSensor == LOW && thirdSensor == LOW) {
      if (millis() - lastBlinkTime >= 1000) {
        blinkState = !blinkState;
        lastBlinkTime = millis();
      }
    } else {
      blinkState = false;
    }
  }

  // Control relay
  if (!dryRun) {
    digitalWrite(relayPin, motorState ? HIGH : LOW);
  } else {
    digitalWrite(relayPin, LOW);
  }

  // Update display
  display.clearDisplay();
  if (dryRun) {
    display.setCursor(0, 2);  //0 , 0
    display.setTextSize(2);
    display.setTextColor(SSD1306_WHITE);
    display.println("  Dry Run");
    display.setTextSize(1);
    display.setCursor(0, 50);
    display.println("Motor OFF");
    display.setCursor(0, 30);
    display.println("      Check Motor");
  } else {
    display.setCursor(0, 0);
    display.setTextSize(2);
    display.setTextColor(SSD1306_WHITE);
    if (lowerSensor == LOW && upperSensor == LOW && thirdSensor == LOW) {
      display.println("Tank Low");
      drawTankLevel(24);
    } else if (lowerSensor == HIGH && upperSensor == HIGH && thirdSensor == HIGH) {
      display.println("Tank Full");
      drawTankLevel(83);
    } else if (lowerSensor == HIGH && upperSensor == LOW && thirdSensor == HIGH) {
      display.println("Tank Mediu");
      drawTankLevel(65);
    } else {
      display.println("Tank Half");
      drawTankLevel(45);
    }

    // Blink "Low" text in Manual mode
    if (!autoMode && lowerSensor == LOW && thirdSensor == LOW && blinkState) {
      display.setCursor(0, 30);
      display.setTextSize(1);
      display.println("                Low");
    }

    display.setTextSize(1);
    display.setCursor(0, 40);
    display.print("Motor: ");
    display.println(motorState ? "ON" : "OFF");

    display.setCursor(0, 52);
    display.print("Mode : ");
    display.println(autoMode ? "Auto" : "Manual");
  }
  display.display();
  delay(1000);
}

// Function to beep the buzzer
void beepBuzzer(int times) {
  for (int i = 0; i < times; i++) {
    digitalWrite(buzzerPin, HIGH);
    delay(100);
    digitalWrite(buzzerPin, LOW);
    delay(100);
  }
}


void drawTankLevel(int level) {

  // Draw the tank outline///
  display.drawRect(90, 18, 30, 40, SSD1306_WHITE);   // 90, 19, 30, 40,


 // Draw the tank with out Top line//
  //display.drawLine(90, 19, 90, 59, SSD1306_WHITE);   // Left line
  //display.drawLine(120, 19, 120, 59, SSD1306_WHITE); // Right line
  //display.drawLine(90, 59, 120, 59, SSD1306_WHITE);  // Bottom line 59


  // Calculate the height of the filled portion
  int fillHeight = map(level, 0, 100, 0, 40);  // 0 , 100, 0, 40
  
  // Draw the filled portion
  display.fillRect(91, 57 - fillHeight, 28, fillHeight, SSD1306_WHITE); //91,58, 28
}