#define BLYNK_TEMPLATE_ID "TMPL6OQr6SKUf"
#define BLYNK_TEMPLATE_NAME "Increment Decrementer Segregation"
#define BLYNK_AUTH_TOKEN "CpMG1yvYkMK1DoPKxg9JUVC7K0YuQmje"

#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
#include <BlynkSimpleEsp32.h> 

LiquidCrystal_I2C lcd(0x27, 16, 2);

// --- Variables ---
int s = 0;          
int startVal = 0;   // V0
int endVal = 0;     // V1
int STEPS = 0;      // V2
int modTRIG = 0;    // V3
int opState = 0;    // V6 Switch State

// Dynamic targets based on the switch
int actualStart = 0;
int actualTarget = 0;

const int buzz = 14; 
char auth[] = BLYNK_AUTH_TOKEN;
char ssid[] = "Wokwi-GUEST"; 
char pass[] = "";

unsigned long lastUpdateTime = 0;
const long interval = 1000;

// --- Playful Sound Functions ---
void playChirp() {
  for (int i = 800; i < 1500; i += 100) {
    tone(buzz, i, 20);
    delay(20);
  }
  noTone(buzz);
}

void playVictory() {
  tone(buzz, 1000, 150); delay(150);
  tone(buzz, 1200, 150); delay(150);
  tone(buzz, 1500, 400); delay(400);
  noTone(buzz);
}

// Helper to update the dynamic range and reset the counter
void applyLogic() {
  if (opState == 0) {
    actualStart = startVal;
    actualTarget = endVal;
  } else {
    actualStart = endVal;
    actualTarget = startVal;
  }
  s = actualStart; // Reset count to the new starting point
  
  // Clear LCD Row 2 on reset
  lcd.setCursor(0, 1);
  lcd.print("                ");
}

// --- Blynk Input Handlers ---
BLYNK_WRITE(V0) { startVal = param.asInt(); applyLogic(); }
BLYNK_WRITE(V1) { endVal = param.asInt(); applyLogic(); }
BLYNK_WRITE(V2) { STEPS = param.asInt(); }
BLYNK_WRITE(V3) { modTRIG = param.asInt(); }

// V6 Switch: Determines if we count Start->End or End->Start
BLYNK_WRITE(V6) {
  opState = param.asInt();
  applyLogic(); // Swaps targets and resets 's'
  
  Serial.print("Mode Switched. Target is now: ");
  Serial.println(actualTarget);
}

BLYNK_CONNECTED() {
  Blynk.syncVirtual(V0, V1, V2, V3, V6);
}

void setup() {
  Serial.begin(9600);
  Blynk.begin(auth, ssid, pass);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Count: ");
  pinMode(buzz, OUTPUT);
}

void loop() {
  Blynk.run();
  unsigned long currentTime = millis();
  if (currentTime - lastUpdateTime >= interval) {
    lastUpdateTime = currentTime;
    updateCounter();
  }
}

void updateCounter() {
  // 1. Directional Math (Auto-detects if it needs to go up or down)
  if (actualStart < actualTarget) {
    s += STEPS;
  } else {
    s -= STEPS;
  }

  // 2. Completion Check
  bool finished = false;
  if (actualStart < actualTarget && s >= actualTarget) finished = true;
  if (actualStart > actualTarget && s <= actualTarget) finished = true;

  if (finished) { 
    lcd.setCursor(7, 0);
    lcd.print(s); // Show final number before reset
    lcd.setCursor(0, 1);
    lcd.print("COMPLETED!!    ");
    Blynk.virtualWrite(V4, s);
    playVictory();
    
    s = actualStart; // Reset to the current logic's start point
    return; 
  }

  // 3. Display
  lcd.setCursor(7, 0);
  lcd.print(s);
  lcd.print("   "); 
  Blynk.virtualWrite(V4, s); 

  // 4. Trigger & LED (V5)
  if (modTRIG > 0 && s % modTRIG == 0 && s != actualStart) {
    lcd.setCursor(0, 1);
    lcd.print("Multi ");
    lcd.print(modTRIG);
    lcd.print("  found!   ");
    Blynk.virtualWrite(V5, 255);
    playChirp();
  } else {
    lcd.setCursor(0, 1);
    lcd.print("               ");
    Blynk.virtualWrite(V5, 0);   
  }
}