//https://forum.arduino.cc/t/why-did-not-recognize-inserted-coin-value/1300588
#include "TM1637.h" //https://github.com/Seeed-Studio/Seeed_Grove_4Digital_Display_g/blob/master/TM1637.h
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
// Define the connections to the Grove 4-digit display
#define CLK 3  // Clock pin to D3
#define DIO 4  // Data pin to D4
// Create instances of the displays
TM1637 display(CLK, DIO);
LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C address 0x27 is common
// Pin connected to the coin acceptor signal
const int coinPin = 2;
volatile int coinCount = 0;
volatile bool coinInsertedFlag = false;
bool timerStarted = false;
unsigned long startTime = 0;
const int requiredCoins = 25;
const int countdownDuration = 180;  // 5 minutes in seconds
// Relay pins
const int relay1Pin = 8;
const int relay2Pin = 6;
const int relay3Pin = 7;
// Button pin
const int buttonPin = 5;
bool buttonPressed = false;
// Buzzer pin
const int buzzerPin = 11;
// Beep settings
const int beepDuration = 500;  // Duration of each beep in milliseconds
const int beepDelay = 500;     // Delay between beeps in milliseconds
// Debounce variables for coin acceptor
unsigned long lastPulseTime = 0;
const unsigned long debounceDelay = 50;  // 50 ms debounce delay
const unsigned long pulseTimeout = 100;  // 100 ms pulse validation window
// Relay states for avoiding unnecessary LCD updates
int lastRelayState = 0;  // 0 = None, 1 = Relay1, 2 = Relay2, 3 = Relay3
// State variables for pulse validation
bool firstPulseDetected = false;
// Interrupt service routine for coin detection with debounce and pulse validation
bool coinFlag = false;
unsigned long currentTime = 0;
//----------------------------------------------------------------
void coinInserted() {
  coinFlag = true;
  // digitalWrite(13, !digitalRead(13));
  digitalWrite(13, HIGH);
}
//----------------------------------------------------------------
void coinDetec() {
  digitalWrite(13, LOW);
  detachInterrupt(digitalPinToInterrupt(coinPin));
  currentTime = millis();
  // Check for debounce
  if (currentTime - lastPulseTime < debounceDelay) {
    Serial.println("y");
    return;  // Ignore if within debounce time
  }
  if()
  coinCount++;  // Valid coin insertion detected
  coinInsertedFlag = true;
}
//----------------------------------------------------------------
void setup() {
  Serial.begin(115200);
  // Initialize the Grove 4-digit display
  display.init();
  display.set(7);  // Set the brightness (0-7, 7 is the max)
  // Initialize the I2C LCD
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Insert Coins: ");
  lcd.setCursor(0, 1);
  lcd.print("0 / 40");
  // Set up coin acceptor input pin
  pinMode(coinPin, INPUT_PULLUP);
  // Set up relay pins
  pinMode(relay1Pin, OUTPUT);
  pinMode(relay2Pin, OUTPUT);
  pinMode(relay3Pin, OUTPUT);
  // Set up button pin
  pinMode(buttonPin, INPUT);
  // Set up buzzer pin
  pinMode(buzzerPin, OUTPUT);
  // Ensure all relays are off initially (HIGH for negative logic)
  digitalWrite(relay1Pin, HIGH);
  digitalWrite(relay2Pin, HIGH);
  digitalWrite(relay3Pin, HIGH);
  // Attach interrupt to the coinPin
  attachInterrupt(digitalPinToInterrupt(coinPin), coinInserted, FALLING);
}
//----------------------------------------------------------------
void beepTone(int frequency) {
  tone(buzzerPin, frequency);  // Start the beep
  delay(beepDuration);         // Duration of the beep
  noTone(buzzerPin);           // Stop the beep
  delay(beepDelay);            // Delay between beeps
}
//----------------------------------------------------------------
void loop() {
  if (coinFlag == true) {
    coinDetec();
    coinFlag = false;
  }
  if (coinInsertedFlag && !timerStarted) {
    // Display the coin count on the 7-segment display
    display.display(0, coinCount / 10);  // Tens place
    display.display(1, coinCount % 10);  // Ones place
    // Update the LCD with the current coin count
    lcd.setCursor(0, 1);
    lcd.print(coinCount);
    lcd.print(" / 40   ");
    if (coinCount >= requiredCoins && !timerStarted) {
      lcd.setCursor(0, 0);
      lcd.print("Press button to");
      lcd.setCursor(0, 1);
      lcd.print("start timer    ");
    }
    // Reset the flag after updating the display
    coinInsertedFlag = false;
    while(digitalRead(coinPin) == LOW){}
    attachInterrupt(digitalPinToInterrupt(coinPin), coinInserted, FALLING);
  }
  if (!timerStarted) {
    // Read the button state
    int buttonState = digitalRead(buttonPin);
    delay(10);  // Add a small delay for button debouncing
    // Check if the required number of coins has been inserted
    if (coinCount >= requiredCoins && buttonState == LOW) {
      buttonPressed = true;
      timerStarted = true;
      startTime = millis();  // Record the start time
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Timer Started!");
    }
  } else {
    // Calculate the time remaining for the countdown
    int elapsedSeconds = (millis() - startTime) / 1000;
    int remainingSeconds = countdownDuration - elapsedSeconds;
    int currentRelayState = 0;  // Variable to track current relay state
    // Relay control and buzzer beeping based on elapsed time (negative logic)
    if ((elapsedSeconds >= 1) && (elapsedSeconds < 90)) {
      // First 90 seconds: Relay 1 on, others off, buzzer tone 1
      digitalWrite(relay1Pin, LOW);
      digitalWrite(relay2Pin, LOW);
      digitalWrite(relay3Pin, HIGH);
      beepTone(1000);         // Beep tone of 1000 Hz
      currentRelayState = 1;  // Relay 1 is active
    } else if ((elapsedSeconds > 90) && (elapsedSeconds < 100)) {
      // Between 90 and 100 seconds: Relay 2 on, others off, buzzer tone 2
      digitalWrite(relay1Pin, LOW);
      digitalWrite(relay2Pin, HIGH);
      digitalWrite(relay3Pin, LOW);
      beepTone(1500);         // Beep tone of 1500 Hz
      currentRelayState = 2;  // Relay 2 is active
    } else if (elapsedSeconds > 100) {
      // After 100 seconds: Relay 3 on, others off, buzzer tone 3
      digitalWrite(relay1Pin, LOW);
      digitalWrite(relay2Pin, HIGH);
      digitalWrite(relay3Pin, HIGH);
      beepTone(2000);         // Beep tone of 2000 Hz
      currentRelayState = 3;  // Relay 3 is active
    }
    // Update the LCD only if the relay state has changed
    if (currentRelayState != lastRelayState) {
      lcd.clear();  // Clear LCD screen only when state changes
      if (currentRelayState == 1) {
        lcd.setCursor(0, 0);
        lcd.print("Please Wait");
        lcd.setCursor(0, 1);
        lcd.print("Warming up");
        // Serial.println("UV ONLY");
      } else if (currentRelayState == 2) {
        lcd.setCursor(0, 0);
        lcd.print("Disinfecting Now!");
        // Serial.println("UV and HEATER");
      } else if (currentRelayState == 3) {
        lcd.setCursor(0, 0);
        lcd.print("Disinfecting Now!");
        // Serial.println("UV ONLY");
      }
      // Update the last relay state
      lastRelayState = currentRelayState;
    }
    // If the countdown is still running
    if (remainingSeconds > 0) {
      // Display the remaining time in MM:SS format
      int minutes = remainingSeconds / 60;
      int seconds = remainingSeconds % 60;
      display.display(0, minutes / 10);  // Tens place of minutes
      display.display(1, minutes % 10);  // Ones place of minutes
      display.display(2, seconds / 10);  // Tens place of seconds
      display.display(3, seconds % 10);  // Ones place of seconds
      display.point(true);               // Show the colon points

    } else {
      // Countdown has ended
      display.clearDisplay();
      timerStarted = false;
      buttonPressed = false;
      coinCount = 0;  // Reset for the next round
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Insert Coins: ");
      // Turn off all relays at the end (HIGH for negative logic)
      digitalWrite(relay1Pin, HIGH);
      digitalWrite(relay2Pin, HIGH);
      digitalWrite(relay3Pin, HIGH);
    }
  }
}