// Pin assignments for components
const int ignitorPin = 2;  // D2
const int combustionBlowerPin = 3;  // D3
const int convectionBlowerPin = 4;  // D4
const int augerMotorPin = 5;  // D5
const int tempSwitchPin = 6;  // D6 (Temperature switch)
const int thermostatPin = 7;  // D7
const int indicatorLightPin = 8; // D8 (Indicator light)

//Timers in milliseconds
const unsigned long augerCycleDuration = 5000;  // 3 seconds
const unsigned long augerRunDuration = 1000;  // 1 second
const unsigned long shutdownDelay = 10000;  // 10 seconds
const unsigned long startupTimeout = 15000;  // 15 seconds

// Run states
enum RunState {
  OFF,
  STARTUP,
  RUNNING,
  SHUTDOWN
};

// Variables to manage the run state and timing
RunState runState = OFF;
unsigned long startTime = 0;
unsigned long shutdownStartTime = 0;
unsigned long startupTimer = 0;

#include <EEPROM.h>

// Variable addresses in EEPROM
int faultAddress = 0;

// Add this variable declaration at the beginning of your code
boolean fault;

void setup() {
  // Initialize pins as OUTPUT or INPUT
  pinMode(ignitorPin, OUTPUT);
  pinMode(combustionBlowerPin, OUTPUT);
  pinMode(convectionBlowerPin, OUTPUT);
  pinMode(augerMotorPin, OUTPUT);
  pinMode(tempSwitchPin, INPUT);
  pinMode(thermostatPin, INPUT);
  pinMode(indicatorLightPin, OUTPUT); // Indicator light as OUTPUT

  // Read fault variable from EEPROM
  fault = EEPROM.read(faultAddress);

  fault = false;  // Initialize fault to false at startup

  // Set the initial state to OFF
  runState = OFF;

 // Initialize serial communication
  Serial.begin(9600);  // Adjust the baud rate accordingly

  // Allow the Arduino to stabilize after a reset
  startTime = millis();
}

void loop() {
  // Your main loop logic goes here
        // Introduce a delay of 100 milliseconds
        delay(100);
  // Read the current state of the thermostat
  boolean thermostatCurrentState = digitalRead(thermostatPin);
  boolean tempSwitchState = digitalRead(tempSwitchPin);

  switch (runState) {
    case OFF:
    Serial.print("OFF");
    Serial.print(", Fault Status: ");
    Serial.println(fault ? "Fault" : "No Fault");

      // All outputs are off, indicator light is off
      stopIgnitor();
      stopCombustionBlower();
      stopConvectionBlower();
      stopAuger();
      digitalWrite(indicatorLightPin, LOW);

        // Introduce a delay of 100 milliseconds
        delay(100);


      // Check if the thermostat is turned on to transition to STARTUP state
      if (thermostatCurrentState == HIGH && fault == false) {
        startupTimer = millis(); // Initialize startupTime when entering STARTUP state
        runState = STARTUP;

      }
      else{
      stopIgnitor();
      stopCombustionBlower();
      stopConvectionBlower();
      stopAuger();
      }

      break;

    case STARTUP:
    Serial.print("STARTUP");
    Serial.print(", millis: ");
    Serial.print(millis());
    Serial.print(", startupTimer: ");
    Serial.print(startupTimer);
    Serial.print(",millis - startupTimer: ");
    Serial.println(millis()-startupTimer);

      // Initialize startup sequence
      startIgnitor();
      startCombustionBlower();  // Combustion blower should be running at the start
      runAugerCycle();  // Start the auger cycle during startup
          
        // Introduce a delay of 100 milliseconds
        delay(100);
      
        // Check if the temperature switch signal is received after the startup timeout
     if (thermostatCurrentState == LOW) {
      runState = SHUTDOWN;
      
   } if (millis() - startupTimer > startupTimeout && tempSwitchState == HIGH) {
         Serial.println("Enter RUNNING temp switch hot(high)");
         runState = RUNNING;

   } else if (millis() - startupTimer > startupTimeout && tempSwitchState == LOW) {
        fault = true;
        Serial.println("Enter SHUTDOWN temp switch cold(low)");
        runState = SHUTDOWN;
      
        // Save the fault variable to EEPROM
        EEPROM.write(faultAddress, fault);
         
   } else {
        // Do nothing in other cases
        //runState = OFF;
       
       }
      // Flash the indicator light fast for startup
      digitalWrite(indicatorLightPin, (millis() / 200) % 2);

      break;


    case RUNNING:
      Serial.println("RUNNING");
      // Check if the thermostat is turned off during the ignitor cycle
      // Turn off the ignitor in the RUNNING state
      stopIgnitor();
      startCombustionBlower();  // Combustion blower should be running during the run cycle
      startConvectionBlower();  // Run the convection blower during the run cycle
      runAugerCycle();

        // Introduce a delay of 100 milliseconds
        delay(100);

      
      if (thermostatCurrentState == LOW) {
        shutdownStartTime = millis();// Initialize shutdownStartTime when entering SHUTDOWN state
        runState = SHUTDOWN;
       Serial.println("Thermostat turned off. Transitioning to SHUTDOWN state.");
       
           // Check if the temperature switch is hot
      }else if (tempSwitchState == LOW) {
       // Temperature switch is cold, initiate shutdown
        fault = true;
        shutdownStartTime = millis();// Initialize shutdownStartTime when entering SHUTDOWN state
        Serial.println("Temperature switch is cold. Initiating shutdown.");
        runState = SHUTDOWN;
                      
        } else {
        // Thermostat is on, continue running
                 
          Serial.println("Running Normal");
        }
            // Indicator light is on for running
            digitalWrite(indicatorLightPin, HIGH);
          
    break;


    case SHUTDOWN:
    Serial.print("SHUTDOWN");
    Serial.print(",millis:  ");
    Serial.print(millis());
    Serial.print(", shutdownStartTime: ");
    Serial.print(shutdownStartTime);
    Serial.print(",millis - SHUTDOWN: ");
    Serial.println(millis() - shutdownStartTime);


      // Ensure auger is off
      stopAuger();
      stopIgnitor();
      startCombustionBlower();


        // Introduce a delay of 100 milliseconds
        delay(100);


         // Keep combustion blower on for 20 seconds
         if (millis() - shutdownStartTime >= shutdownDelay) {
        stopCombustionBlower();
        stopConvectionBlower();  // Stop the convection blower after the shutdown delay
        Serial.println("SHUTDOWN");
        runState = OFF;  // Transition to OFF state
       }

         // Flash the indicator light slowly for shutdown
         digitalWrite(indicatorLightPin, (millis() / 1000) % 2);
         break;

          default:
          // Do nothing in other cases
          break;
  }

}
// Add or modify functions for combustion blower and convection blower as needed
void startCombustionBlower() {
  digitalWrite(combustionBlowerPin, HIGH);
}

void stopCombustionBlower() {
  digitalWrite(combustionBlowerPin, LOW);
}

void startConvectionBlower() {
  digitalWrite(convectionBlowerPin, HIGH);
}

void stopConvectionBlower() {
 digitalWrite(convectionBlowerPin, LOW);
}

// Add or modify functions for other components as needed
void startIgnitor() {
  digitalWrite(ignitorPin, HIGH);
}

void stopIgnitor() {
  digitalWrite(ignitorPin, LOW);
}

void runAugerCycle() {
  // Run the auger for 1 second every 3 seconds
  unsigned long elapsedTime = millis() - startTime;
  if (elapsedTime % augerCycleDuration < augerRunDuration) {
    digitalWrite(augerMotorPin, HIGH);
  } else {
    digitalWrite(augerMotorPin, LOW);
  }
}

void stopAuger() {
  digitalWrite(augerMotorPin, LOW);
}