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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 32
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

const int potentiometerPin = A0; // Potekas
const int relayPin = 2;          // Relee
const int startButtonPin = 3;    // Start
const int modeSwitchPin = 4;     // Mode

bool currentMode = false;        
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;
int frequency = 0;               // Sagedus(hz)
float rpm = 0;                   // Pöörded(rpm)
const int dutyCycle = 5;        // Dutycycle(nt95%)

void setup() {
  pinMode(relayPin, OUTPUT);
  pinMode(startButtonPin, INPUT_PULLUP);
  pinMode(modeSwitchPin, INPUT_PULLUP);

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

  digitalWrite(relayPin, LOW);
}

void loop() {
  currentMode = !digitalRead(modeSwitchPin);

  displayModeInfo(currentMode);

  if (!currentMode) {
    frequency = map(analogRead(potentiometerPin), 0, 1023, 1, 40); // Map potentiometer to 1-40 Hz
    rpm = frequency * 60.0;  // Convert frequency (Hz) to RPM
    displayFrequencyAndRPM(frequency, rpm, dutyCycle);  // Show frequency and RPM on screen
  }

  // Check for start button press and handle the two modes
  if (isButtonPressed(startButtonPin)) {
    if (currentMode) {
      // Mode 2: Relay stays ON for 10 seconds
      activateRelayForDuration(10000);
    } else {
      // Mode 1: Relay operates at the set frequency and fixed duty cycle for 10 seconds
      runRelayWithFixedDutyCycle(frequency);
    }
  }
}

void activateRelayForDuration(unsigned long duration) {
  digitalWrite(relayPin, HIGH);
  delay(duration);
  digitalWrite(relayPin, LOW);
}

void runRelayWithFixedDutyCycle(int frequency) {
  unsigned long startTime = millis();
  unsigned long cycleTime = 1000 / frequency;  // Total cycle time for the frequency (in milliseconds)
  unsigned long onTime = cycleTime * dutyCycle / 100;  // Calculate ON time based on fixed duty cycle
  unsigned long offTime = cycleTime - onTime;  // Calculate OFF time

  while (millis() - startTime < 10000) {  // Run for 10 seconds
    // Turn relay ON
    digitalWrite(relayPin, HIGH);
    displayRunningFrequency(frequency, dutyCycle);  // Display frequency and duty cycle while relay is active
    delay(onTime);

    // Turn relay OFF
    digitalWrite(relayPin, LOW);
    displayRunningFrequency(frequency, dutyCycle);  // Display frequency and duty cycle while relay is off
    delay(offTime);
  }
}

bool isButtonPressed(int pin) {
  int reading = digitalRead(pin);
  if (reading == LOW) {
    unsigned long currentTime = millis();
    if ((currentTime - lastDebounceTime) > debounceDelay) {
      lastDebounceTime = currentTime;
      return true;
    }
  }
  return false;
}

void displayModeInfo(bool mode) {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);

  // Display Mode Info
  if (mode) {
    display.println("Mode 2: Relee 10s");
  } else {
    display.println("Mode 1: Lulitus");
  }
  display.display();
}

void displayFrequencyAndRPM(int frequency, float rpm, int dutyCycle) {
  display.setCursor(0, 10);
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  
  // Display frequency, RPM, and fixed duty cycle
  display.print("Set Freq: ");
  display.print(frequency);
  display.println(" Hz");
  display.print("RPM: ");
  display.print(rpm);
  display.println();
  display.print("Duty Cycle: ");
  display.print(dutyCycle);
  display.println(" %");
  display.display();
}

void displayRunningFrequency(int frequency, int dutyCycle) {
  display.setCursor(0, 10);
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  
  // Display running frequency and fixed duty cycle during relay operation
  display.print("Freq: ");
  display.print(frequency);
  display.print(" Hz, ");
  display.print("Duty: ");
  display.print(dutyCycle);
  display.println(" %");
  display.display();
}