#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include "ThingSpeak.h"
#include <SPI.h>
#include <Ethernet.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int total_height = 30; // garbage bin height in CM
const int hold_height = 25;  // garbage holding capacity (height) in CM
const int full_threshold = 100; // Garbage level threshold for full (in percentage)
const int empty_threshold = 0; // Garbage level threshold for empty (in percentage)

int Minute = 1; // Data update in min.

unsigned long Channel_ID = 987654; // Channel ID
const char *WriteAPIKey = "XTS8MPCWWZZSJISU"; // Your write API Key

const int trigger = 7;
const int echo = 6;
long Time;
int x;
int i;
int distanceCM;
int resultCM;
int bin_lvl = 100;
int snsr_to_max = 90;
const int Field_number = 1;

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; // Ethernet shield MAC address
IPAddress ip(192, 168, 1, 177);                      // Arduino IP address
EthernetClient client;

void setup() {
  // Initialize the LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("IoT Garbage lvl");
  lcd.setCursor(0, 1);
  lcd.print("Monitoring Sys.");

  // Start the Serial for debugging
  Serial.begin(9600);

  // Initialize Ethernet and ThingSpeak
  Ethernet.begin(mac, ip);
  ThingSpeak.begin(client);

  // Set pin modes
  pinMode(trigger, OUTPUT);
  pinMode(echo, INPUT);

  // Calculate the sensor to max distance
  snsr_to_max = total_height - hold_height;

  // Delay for initialization
  delay(2500);
}

void loop() {
  // Measure the garbage level
  measure();

  // Display the garbage level on the LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Garbage Level:");

  // Check if the garbage level is full or empty
  if (bin_lvl >= full_threshold) {
    Serial.println("Garbage Level: Full");
    lcd.setCursor(0, 1);
    lcd.print("Full"); // Display full garbage level on LCD
  } else if (bin_lvl <= empty_threshold) {
    Serial.println("Garbage Level: Empty");
    lcd.setCursor(0, 1);
    lcd.print("Empty"); // Display empty garbage level on LCD
  } else {
    Serial.println("Garbage Level: ");
    lcd.setCursor(5, 1);
    lcd.print(bin_lvl);
    lcd.print('%');
  }

  // Debug print to Serial
  Serial.print("Garbage Level: ");
  Serial.print(bin_lvl);
  Serial.println("%");

  // Upload the data to ThingSpeak
  upload();

  // Standby loop
  for (i = 0; i < Minute; i++) {
    Serial.println("-------------------------");
    Serial.println("System Standby....");
    Serial.print(i);
    Serial.println(" Minutes elapsed.");
    delay(60000); // 1 minute delay
  }
}

void upload() {
  // Write the data to ThingSpeak
  x = ThingSpeak.writeField(Channel_ID, Field_number, bin_lvl, WriteAPIKey);
  if (x == 200) {
    Serial.println("Data Updated.");
  } else {
    Serial.println("Data upload failed, retrying....");
    delay(15000);
    static int retry_count = 0;
    if (retry_count < 3) { // limit retries to 3 times
      retry_count++;
      upload();
    } else {
      Serial.println("Failed to upload data after multiple attempts.");
      retry_count = 0; // reset retry counter
    }
  }
}

void measure() {
  delay(100);
  digitalWrite(trigger, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigger, LOW);
  Time = pulseIn(echo, HIGH);
  distanceCM = (Time / 2) * 0.0343; // corrected distance calculation
  resultCM = distanceCM;

  bin_lvl = map(resultCM, snsr_to_max, total_height, 100, 0);
  bin_lvl = constrain(bin_lvl, 0, 100);
}