#include <HX711.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <HTTPClient.h>
#include <SD.h>
#include <EEPROM.h>

// Pin Definitions
#define LOADCELL1_DOUT_PIN 4
#define LOADCELL1_SCK_PIN 5
#define LOADCELL2_DOUT_PIN 16
#define LOADCELL2_SCK_PIN 17
#define LOADCELL3_DOUT_PIN 18
#define LOADCELL3_SCK_PIN 19
#define LOADCELL4_DOUT_PIN 21
#define LOADCELL4_SCK_PIN 22
#define SD_CS_PIN 15

// I2C LCD Setup
#define I2C_ADDRESS 0x27
#define LCD_COLUMNS 16
#define LCD_ROWS 2
LiquidCrystal_I2C lcd(I2C_ADDRESS, LCD_COLUMNS, LCD_ROWS);

// Wi-Fi Credentials
const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";

// Cloud Endpoint
const char* serverUrl = "http://your-cloud-endpoint.com/api/data";

// HX711 Setup
HX711 scale1, scale2, scale3, scale4;

// Variables
float totalWeight = 0;
int sackCount = 0;
bool sackDetected = false;
String flourCategory = "Default"; // Default category, updated via web app
bool wifiConnected = false;

void setup() {
  Serial.begin(115200);

  // Initialize I2C LCD
  lcd.begin(16,2);
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Initializing...");

  // Initialize HX711 Load Cells
  scale1.begin(LOADCELL1_DOUT_PIN, LOADCELL1_SCK_PIN);
  scale2.begin(LOADCELL2_DOUT_PIN, LOADCELL2_SCK_PIN);
  scale3.begin(LOADCELL3_DOUT_PIN, LOADCELL3_SCK_PIN);
  scale4.begin(LOADCELL4_DOUT_PIN, LOADCELL4_SCK_PIN);

  // Calibrate Load Cells (adjust calibration factor as needed)
  scale1.set_scale(2280.f); // Replace with your calibration factor
  scale2.set_scale(2280.f);
  scale3.set_scale(2280.f);
  scale4.set_scale(2280.f);
  scale1.tare();
  scale2.tare();
  scale3.tare();
  scale4.tare();

  // Initialize SD Card
  if (!SD.begin(SD_CS_PIN)) {
    Serial.println("SD Card initialization failed!");
    lcd.setCursor(0, 1);
    lcd.print("SD Card Error!");
  } else {
    Serial.println("SD Card initialized.");
  }

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  Serial.println("Connecting to Wi-Fi...");
  lcd.setCursor(0, 0);
  lcd.print("Connecting WiFi...");
  int retries = 0;
  while (WiFi.status() != WL_CONNECTED && retries < 10) {
    delay(1000);
    Serial.print(".");
    retries++;
  }
  if (WiFi.status() == WL_CONNECTED) {
    wifiConnected = true;
    Serial.println("\nConnected to Wi-Fi!");
    lcd.setCursor(0, 0);
    lcd.print("WiFi Connected! ");
  } else {
    Serial.println("\nFailed to connect to Wi-Fi.");
    lcd.setCursor(0, 0);
    lcd.print("WiFi Failed!    ");
  }
}

void loop() {
  // Read weight from all load cells
  float weight1 = scale1.get_units(10); // Average of 10 readings
  float weight2 = scale2.get_units(10);
  float weight3 = scale3.get_units(10);
  float weight4 = scale4.get_units(10);

  // Calculate total weight
  totalWeight = weight1 + weight2 + weight3 + weight4;
  Serial.print("Total Weight: ");
  Serial.println(totalWeight);

  // Display total weight on LCD
  lcd.setCursor(0, 1);
  lcd.print("Weight: ");
  lcd.print(totalWeight);
  lcd.print(" kg  ");

  // Detect a 40kg sack
  if (totalWeight >= 39.5 && totalWeight <= 40.5 && !sackDetected) { // Tolerance of ±0.5kg
    sackCount++;
    sackDetected = true;
    Serial.print("Sack detected! Total sacks: ");
    Serial.println(sackCount);
  } else if (totalWeight < 1.0) { // Reset detection when weight is removed
    sackDetected = false;
  }

  // Store data locally if Wi-Fi is not connected
  if (!wifiConnected) {
    storeDataOnSD(sackCount, flourCategory);
  } else {
    // Send data to the cloud
    if (sendDataToCloud(sackCount, flourCategory)) {
      Serial.println("Data sent to cloud.");
    } else {
      Serial.println("Failed to send data to cloud. Storing locally.");
      storeDataOnSD(sackCount, flourCategory);
    }
  }

  delay(5000); // Wait 5 seconds before next reading
}

bool sendDataToCloud(int sackCount, String flourCategory) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    http.begin(serverUrl);
    http.addHeader("Content-Type", "application/json");

    String payload = "{\"sackCount\":" + String(sackCount) + ",\"flourCategory\":\"" + flourCategory + "\",\"totalWeight\":" + String(totalWeight) + "}";
    int httpResponseCode = http.POST(payload);

    http.end();

    if (httpResponseCode == 200) {
      return true;
    }
  }
  return false;
}

void storeDataOnSD(int sackCount, String flourCategory) {
  File file = SD.open("/data.txt", FILE_APPEND);
  if (file) {
    file.println("Sacks: " + String(sackCount) + ", Category: " + flourCategory + ", Weight: " + String(totalWeight) + " kg");
    file.close();
    Serial.println("Data stored on SD card.");
  } else {
    Serial.println("Failed to open file on SD card.");
  }
}

void recoverDataFromSD() {
  File file = SD.open("/data.txt");
  if (file) {
    while (file.available()) {
      String data = file.readStringUntil('\n');
      if (sendDataToCloud(parseSackCount(data), parseFlourCategory(data))) {
        Serial.println("Recovered data sent to cloud: " + data);
      } else {
        Serial.println("Failed to send recovered data: " + data);
      }
    }
    file.close();
    SD.remove("/data.txt"); // Clear the file after recovery
  } else {
    Serial.println("No data to recover from SD card.");
  }
}

int parseSackCount(String data) {
  int start = data.indexOf("Sacks: ") + 7;
  int end = data.indexOf(",", start);
  return data.substring(start, end).toInt();
}

String parseFlourCategory(String data) {
  int start = data.indexOf("Category: ") + 10;
  int end = data.indexOf(",", start);
  return data.substring(start, end);
}