#include <Arduino.h>

#define TEMP_PIN A0
#define POT_PIN A1
#define FANLED_PIN 9
#define BUTTON_PIN 2

bool manualMode=false;
float temperature=0.0;
int dutyCycle=0;

unsigned long lastTempRead=0;
unsigned long lastPWMUpdate=0;
unsigned long lastSerialSend=0;
unsigned long lastButtonCheck=0;

bool lastButtonState=HIGH;

void setup(){
  pinMode(FANLED_PIN,OUTPUT);
  pinMode(BUTTON_PIN,INPUT_PULLUP);
  Serial.begin(9600);
}

void loop(){
  unsigned long currentMillis=millis();

  if (currentMillis-lastTempRead>=500) {
    int adcValue=analogRead(TEMP_PIN);
    temperature=map(adcValue,0,1023,0,50);
    lastTempRead=currentMillis;
  }
  if (currentMillis-lastPWMUpdate>=200){
    if (!manualMode){
      dutyCycle=map(constrain(temperature,20,40),20,40,0,255);
    }else{
      int potValue=analogRead(POT_PIN);
      dutyCycle=map(potValue,0,1023,0,255);
    }
    analogWrite(FANLED_PIN,dutyCycle);
    lastPWMUpdate=currentMillis;
  }
  if (currentMillis-lastButtonCheck>=10) {
    bool currentState=digitalRead(BUTTON_PIN);
    if (currentState==LOW&&lastButtonState==HIGH){
      delay(50);
      if (digitalRead(BUTTON_PIN)==LOW) {
        manualMode=!manualMode;
      }
    }
    lastButtonState=currentState;
    lastButtonCheck=currentMillis;
  }

  if (currentMillis-lastSerialSend>=1000){
    String modeStr=manualMode ? "Manual" : "Auto";
    Serial.print("Mod:");
    Serial.print(modeStr);
    Serial.print(",Temp:");
    Serial.print(temperature, 2);
    Serial.print("C,Duty: ");
    Serial.println(dutyCycle);
    lastSerialSend=currentMillis;
  }
}