// Include necessary libraries
#include <Arduino.h>

// Define relay control pin
#define RELAY_PIN 6

// Define sensor pins
#define SENSOR_1 A0
#define SENSOR_2 A1
#define SENSOR_3 A2
#define SENSOR_4 A3
#define SENSOR_5 A4
#define SENSOR_6 A5

// Define timing constants (leave as you had them)
#define ZERO_CHECK_DURATION 10000   // time setting to check for Door open
#define RELAY_PULSE_DURATION 20000  // x seconds relay pulse
#define SENSOR_CHECK_INTERVAL 1000  // Check sensors every 1 second  

// New: Reset duration when ALL doors remain closed -> reset relay (2 minutes)
#define RESET_DURATION 120000  // 2 minutes in ms

// Relay active level in your sketch: you used HIGH in setup as "off"
// so keep the same logic: RELAY_ON = LOW, RELAY_OFF = HIGH
const uint8_t RELAY_ON = LOW;
const uint8_t RELAY_OFF = HIGH;

// Latch state: true when relay has been triggered and latched
bool relayLatched = false;

// Timer for reset when ALL sensors are closed
unsigned long allClosedStart = 0;

// Helper: array of sensor pins for easy iteration
const int sensorPins[6] = { SENSOR_1, SENSOR_2, SENSOR_3, SENSOR_4, SENSOR_5, SENSOR_6 };

void setup() {
  // Start serial communication
  Serial.begin(9600);
  while (!Serial)
    ;  // Wait for serial monitor

  // Set relay pin as output
  pinMode(RELAY_PIN, OUTPUT);

  // Set sensor pins as input
  pinMode(SENSOR_1, INPUT_PULLUP);
  pinMode(SENSOR_2, INPUT_PULLUP);
  pinMode(SENSOR_3, INPUT_PULLUP);
  pinMode(SENSOR_4, INPUT_PULLUP);
  pinMode(SENSOR_5, INPUT_PULLUP);
  pinMode(SENSOR_6, INPUT_PULLUP);

  Serial.println("System Initialized...");
  Serial.println("Monitoring for continuous zero readings...");
  // Turn relay OFF initially
  digitalWrite(RELAY_PIN, RELAY_OFF);
}

void loop() {
  // Check each sensor for continuous zero readings
  checkSensorForContinuousZero(SENSOR_1, "Sensor 1");
  checkSensorForContinuousZero(SENSOR_2, "Sensor 2");
  checkSensorForContinuousZero(SENSOR_3, "Sensor 3");
  checkSensorForContinuousZero(SENSOR_4, "Sensor 4");
  checkSensorForContinuousZero(SENSOR_5, "Sensor 5");
  checkSensorForContinuousZero(SENSOR_6, "Sensor 6");

  // After checking sensors, evaluate reset condition:
  checkAllClosedForReset();

  delay(100);  // Small delay between sensor checks (preserves original pacing)
}

void checkSensorForContinuousZero(int sensorPin, String sensorName) {
  Serial.println("Checking " + sensorName + "...");

  unsigned long startTime = millis();
  bool continuousZero = true;

  // Monitor sensor for ZERO_CHECK_DURATION
  while (millis() - startTime < ZERO_CHECK_DURATION) {
    int sensorValue = analogRead(sensorPin);
    Serial.println(sensorName + " reading: " + String(sensorValue));

    // If sensor is not zero, break the continuous zero check
    if (sensorValue != 0) {
      continuousZero = false;
      Serial.println(sensorName + " not zero - check failed");
      break;
    }

    // Wait SENSOR_CHECK_INTERVAL before next reading
    delay(SENSOR_CHECK_INTERVAL);
  }

  // If sensor was zero for continuous ZERO_CHECK_DURATION, trigger relay (only if not already latched)
  if (continuousZero) {
    Serial.println(sensorName + " was ZERO for required duration.");

    if (!relayLatched) {
      Serial.println(sensorName + " TRIGGERING RELAY (and latching)!");
      // Relay cycle (kept same as original behavior)
      Serial.println("Starting relay pulse...");

      // Turn relay ON (active LOW in your setup)
      digitalWrite(RELAY_PIN, RELAY_ON);
      Serial.println("Relay ON (LOW)");

      // Set latched state (so reset logic can later de-assert it)
      relayLatched = true;
      Serial.println("Relay latched. Waiting for reset condition (all doors closed for 2 minutes).");

      // Reset allClosedStart because we just triggered relay and want a fresh wait
      allClosedStart = 0;
    } else {
      Serial.println("Relay already latched. Ignoring repeated trigger.");
    }
  }
}

// Check if ALL sensors are non-zero continuously for RESET_DURATION; then reset relay
void checkAllClosedForReset() {
  // If relay is not latched there's nothing to reset
  if (!relayLatched) {
    allClosedStart = 0;
    return;
  }

  // Read all sensors
  bool allClosed = true;
  for (int i = 0; i < 6; i++) {
    int val = analogRead(sensorPins[i]);
    // A reading of 0 = open in your logic, so non-zero means closed
    if (val == 0) {
      allClosed = false;
      break;
    }
  }

  if (allClosed) {
    if (allClosedStart == 0) {
      allClosedStart = millis();
      Serial.println("All sensors read non-zero. Starting reset countdown...");
    } else {
      unsigned long elapsed = millis() - allClosedStart;
      // If all closed for RESET_DURATION, reset the relay
      if (elapsed >= RESET_DURATION) {
        Serial.println("All doors remained closed for 2 minutes -> RESETTING RELAY");
        relayLatched = false;
        Serial.println("Relay OFF (HIGH)");

        digitalWrite(RELAY_PIN, RELAY_OFF);  // Ensure relay is OFF
        allClosedStart = 0;
      } else {
        // optional: print countdown occasionally (uncomment if desired)
        // Serial.println("Reset countdown: " + String((RESET_DURATION - elapsed) / 1000) + " seconds remaining");
      }
    }
  } else {
    // Not all closed — cancel/reset countdown
    if (allClosedStart != 0) {
      Serial.println("A door opened again - reset countdown cancelled.");
    }
    allClosedStart = 0;
  }
}