#include <AccelStepper.h>
#include "HX711.h"
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// new 
#include <WiFi.h> 
#include <ThingSpeak.h>

unsigned long int ChannelNumber = 2628596;
const char* writeAPIKey = "PVPDDL1304HOFIJM";
const char* readAPIKey = "VD1J40LPX08544KW";
const char* server = "api.thingspeak.com";   

// Stepper Motor Connections
#define STEP_PIN 32
#define DIR_PIN 33
#define ENABLE_PIN 25

// Load Cell Pins (Primary for Weight Detection)
#define LOADCELL_DOUT_PIN 4
#define LOADCELL_SCK_PIN 16

// Load Cell Pins (Secondary for Restock Detection)
#define LOADCELL_DOUT_PIN_2 17
#define LOADCELL_SCK_PIN_2 19

// LED Pins
#define RED_LED_PIN 26
#define GREEN_LED_PIN 27

// Switch Pins
#define STOCK_SWITCH_PIN 12  // Switch for stocking mechanism
#define REMOVE_WEIGHT_SWITCH_PIN 13  // Switch to remove 50kg from total weight

// Emergency Stop Button Pin
#define EMERGENCY_STOP_PIN 14 // Define the pin for the emergency stop button

// Ultrasonic Sensor Connections
const int trigPin = 5;
const int echoPin = 18;

// Distance and Weight Thresholds
const float distanceThreshold = 20.0; // 20 cm
const float weightThreshold = 25.0;   // 25 kg

// Inventory Management Variables
int item1Count = 0; // Items added when motor runs clockwise
int item2Count = 0; // Items added when motor runs counterclockwise
float totalWeight = 35; // Total accumulated weight
float restockWeight = 95;

// Create an instance of the AccelStepper library
AccelStepper stepper(AccelStepper::DRIVER, STEP_PIN, DIR_PIN);

// Create instances of the HX711 library
HX711 scale;
HX711 scale2; // Secondary load cell for restocking

LiquidCrystal_I2C lcd(0x27, 20, 4); // I2C address 0x27, 20 columns, 4 rows

// Calibration factors for the load cells (adjust as needed)
const float calibrationFactor1 = 420.0; // Calibration factor for primary load cell
const float calibrationFactor2 = 420.0; // Calibration factor for secondary load cell

// Password Variables
const String correctPassword = "1234"; // Set your password here
String enteredPassword = "";

void setup() {
  // Set up the stepper motor
  pinMode(ENABLE_PIN, OUTPUT);
  digitalWrite(ENABLE_PIN, LOW); // Enable the driver
  
  stepper.setMaxSpeed(1000); // Set max speed (steps per second)
  stepper.setAcceleration(500); // Set acceleration (steps per second^2)

  // Set up the ultrasonic sensor
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  // Set up the load cells
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
  scale.set_scale(calibrationFactor1); // Set the calibration factor for primary load cell
  scale.tare(); // Reset the scale to 0

  scale2.begin(LOADCELL_DOUT_PIN_2, LOADCELL_SCK_PIN_2);
  scale2.set_scale(calibrationFactor2); // Set the calibration factor for secondary load cell
  scale2.tare(); // Reset the secondary scale to 0

  // Set up LEDs
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  digitalWrite(RED_LED_PIN, LOW);  // Ensure LEDs are off initially
  digitalWrite(GREEN_LED_PIN, LOW);

  // Set up switches
  pinMode(STOCK_SWITCH_PIN, INPUT_PULLUP); // Stock switch
  pinMode(REMOVE_WEIGHT_SWITCH_PIN, INPUT_PULLUP); // Remove weight switch

  // Set up the emergency stop button
  pinMode(EMERGENCY_STOP_PIN, INPUT_PULLUP); // Emergency stop button

  // Set up the LCD
  lcd.begin(20, 4);
  lcd.init();
  lcd.backlight();

  Serial.begin(115200);
  lcd.clear();
  lcd.print("Enter Password:");
  enteredPassword = ""; // Reset entered password
  getPassword(); // Get password input

  //New 
  // Initialising WiFi
  char ssid[] = "Wokwi-GUEST"; // Replace with your WiFi SSID
  char pass[] = ""; // Replace with your WiFi password
  WiFiClient client;

  WiFi.begin(ssid, pass);
  while(WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }
  Serial.println();
  Serial.println("WiFi Connected.");
  Serial.println(WiFi.localIP());
  ThingSpeak.begin(client);
}

void loop() {
  // Check if the emergency stop button is pressed
  if (digitalRead(EMERGENCY_STOP_PIN) == HIGH) {
    // If the emergency stop button is pressed
    lcd.clear();
    lcd.print("Emergency Shutdown");
    stepper.stop(); // Stop the stepper motor
    digitalWrite(RED_LED_PIN, LOW); // Turn off LEDs
    digitalWrite(GREEN_LED_PIN, LOW);
    while (true) {
      // Stay in this loop until the board is reset
    }
  }

  // Only run the main functionality if the password is correct
  if (enteredPassword == correctPassword) {
    runMainFunctionality();
  } else {
    lcd.setCursor(0, 0);
    lcd.print("Access Denied!   ");
    delay(1000); // Show access denied message for a second
    lcd.clear();
    lcd.print("Enter Password:  ");
    enteredPassword = ""; // Reset entered password
    getPassword(); // Get password input
  }
}

void getPassword() {
  // This function simulates getting a password input
  // In a real application, you would read from a keypad or serial input
  while (true) {
    if (Serial.available()) {
      char ch = Serial.read();
      if (ch == '\n') { // Enter key pressed
        break;
      } else {
        enteredPassword += ch; // Append character to entered password
        lcd.setCursor(0, 1);
        lcd.print("Password: " + enteredPassword);
      }
    }
  }
  lcd.clear();
}

void runMainFunctionality() {
  long duration;
  float distance;
  float weight;

  // Trigger the ultrasonic sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measure the echo pulse duration
  duration = pulseIn(echoPin, HIGH);

  // Convert duration to distance
  distance = (duration * 0.034) / 2;

  // Read the weight from the primary load cell
  if (scale.wait_ready_timeout(200)) {
    weight = scale.get_units();
    Serial.print("Weight: ");
    Serial.print(weight);
    Serial.println(" Kg");
  } else {
    Serial.println("Primary HX711 not found.");
    return; // Exit loop if scale is not ready
  }

  // Read the weight from the secondary load cell for restocking
  if (scale2.wait_ready_timeout(200)) {
    restockWeight = scale2.get_units() * 10; // Get restock weight
    Serial.print("Restock Weight: ");
    Serial.print(restockWeight);
    Serial.println(" Kg");
  } else {
    Serial.println("Secondary HX711 not found.");
  }

  // Check if the stock switch is ON
  if (digitalRead(STOCK_SWITCH_PIN) == LOW) {
    // Only allow stocking if the remove weight switch is OFF
    if (digitalRead(REMOVE_WEIGHT_SWITCH_PIN) == HIGH) {
      if (distance < distanceThreshold) {
        if (weight > 0) {
          if (weight > weightThreshold) {
            stepper.setSpeed(-200); // Negative speed for counterclockwise rotation
            digitalWrite(RED_LED_PIN, HIGH);  // Turn on red LED
            digitalWrite(GREEN_LED_PIN, LOW); // Turn off green LED
            item2Count++; // Increment Item 2 count
            totalWeight += weight; // Update total weight
            lcd.clear();
            lcd.setCursor(0, 2);
            lcd.print("Total W: ");
            lcd.print(totalWeight);
            Serial.println("Weight limit exceeded, spinning counterclockwise!");
          } else {
            stepper.setSpeed(200); // Positive speed for clockwise rotation
            digitalWrite(RED_LED_PIN, LOW);  // Turn off red LED
            digitalWrite(GREEN_LED_PIN, HIGH); // Turn on green LED
            item1Count++; // Increment Item 1 count
            totalWeight += weight; // Update total weight
            lcd.clear();
            lcd.setCursor(0, 2);
            lcd.print("Total W: ");
            lcd.print(totalWeight);
            Serial.println("Conveyor running, spinning clockwise...");
          }
        }
        stepper.runSpeed(); // Continuously run the stepper motor at the set speed
      } else {
        stepper.stop(); // Stop the motor if distance is greater than or equal to the threshold
        digitalWrite(RED_LED_PIN, LOW); // Turn off red LED
        digitalWrite(GREEN_LED_PIN, LOW); // Turn off green LED
        Serial.println("Distance too great, stopping conveyor.");
      }
    } else {
      // If removing switch is ON, stop the motor
      stepper.stop();
      digitalWrite(RED_LED_PIN, LOW); // Turn off red LED
      digitalWrite(GREEN_LED_PIN, LOW); // Turn off green LED
      Serial.println("Removing in progress, stopping stocking conveyor.");
    }
  }

  // Display item counts and total weight on the LCD
  lcd.setCursor(0, 0);
  lcd.print("Item 1: ");
  lcd.print(item1Count);

  lcd.setCursor(0, 1);
  lcd.print("Item 2: ");
  lcd.print(item2Count);

    if (totalWeight < restockWeight) {
    lcd.setCursor(0, 3);
    lcd.print("Restock Needed!  ");
    Serial.println("Restock needed!");

    ThingSpeak.setField(1, totalWeight); // Set Field 1 with totalWeight value
    int responseCode = ThingSpeak.writeFields(ChannelNumber, writeAPIKey);

    if (responseCode == 200) {
      Serial.println("Update successful");

  } else {
    lcd.setCursor(0, 3);
    lcd.print("Restock Not Needed");
  }
  delay(1000); // Shorter delay to improve responsiveness


  // Check if the remove weight switch is pressed
  if (digitalRead(REMOVE_WEIGHT_SWITCH_PIN) == LOW) {
    if (digitalRead(STOCK_SWITCH_PIN) == HIGH) {
      if(totalWeight<50)
      {
        lcd.clear();
        lcd.print("Add More Weights");
        delay(1000);
        lcd.clear();
      }
      else{
        totalWeight -= 50.0; // Decrease total weight by 50 kg
      if (totalWeight < 0) {
        totalWeight = 0; // Prevent negative weight
      }
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Decreased by 50kg");
      lcd.setCursor(0, 2);
      lcd.print("Total W: ");
      lcd.print(totalWeight);
      delay(3000);
      lcd.clear(); // Delay to show the message
      }
      
    }
  }
}

}