#define BLYNK_PRINT Serial

#define BLYNK_TEMPLATE_ID "TMPL6ZhZufyqA"
#define BLYNK_TEMPLATE_NAME "wator"
#define BLYNK_AUTH_TOKEN "yo_irz_3silctp6m7xXt6lY-KfxBA1uC"

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <WiFiClient.h>
#include <HTTPClient.h>
#include <BlynkSimpleEsp32.h>

// WiFi Credentials
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// LINE Notify Access Token
String lineToken = "83jNlCXVFod5ZNB7S21X7wmUrKTLp1k2YmRlD3KVtua"; // Replace with your LINE Notify Access Token

// Ultrasonic Sensor Pins
#define TRIG_PIN 15
#define ECHO_PIN 4
#define BUZZER_PIN 5

// Variables
long echo;
float distance;
int currentLevel = -1;    // Keeps track of current alert level (-1 = undefined)
int notifyCount[3] = {0}; // Array to track LINE Notify count for each level

// LCD Configuration (I2C)
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C Address: 0x27, 16 columns, 2 rows

void setup() {
  Serial.begin(9600);

  // Set up I2C pins manually for ESP32
  Wire.begin(22, 21); // SDA = D22, SCL = D21

  // Initialize pins
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Initializing...");

  // Connect to WiFi
  connectToWiFi();

  // Connect to Blynk
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Connecting Blynk");
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);

  lcd.setCursor(0, 1);
  lcd.print("Blynk Connected!");
  delay(2000);
  lcd.clear();
}

void loop() {
  // Check WiFi connection
  if (WiFi.status() != WL_CONNECTED) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("WiFi Disconnected!");
    delay(3000); // Wait for 3 seconds before retrying
    connectToWiFi();
  } else {
    Blynk.run();
    readSensor();
  }
}

void connectToWiFi() {
  lcd.setCursor(0, 1);
  lcd.print("Connecting WiFi");
  WiFi.begin(ssid, pass);
  int dotCount = 0;

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    lcd.setCursor(15 - dotCount, 1); // Add dots as connecting
    lcd.print(".");
    dotCount++;
    if (dotCount > 15) {
      lcd.setCursor(0, 1);
      lcd.print("Connecting WiFi");
      dotCount = 0;
    }
  }

  lcd.setCursor(0, 1);
  lcd.print("WiFi Connected! ");
  Serial.println("\nWiFi Connected!");
  delay(2000);
}

long previousMillis = 0;

void readSensor() {
  if (millis() - previousMillis > 2000) { // Run every 2 seconds
    previousMillis = millis();

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

    // Read echo time and calculate distance
    echo = pulseIn(ECHO_PIN, HIGH);
    distance = (echo / 2.0) / 29.1; // Convert to cm

    // Display distance on LCD
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Distance:");
    lcd.print(distance);
    lcd.print(" cm");

    // Send distance to API
    sendToAPI(distance);

    // Determine the alert level based on distance
    int newLevel;
    if (distance > 50) {
      newLevel = 0; // Level 0: Safe Distance
    } else if (distance <= 50 && distance >= 20) {
      newLevel = 1; // Level 1: Caution
    } else {
      newLevel = 2; // Level 2: Danger
    }

    // Handle notifications and actions when level changes
    if (newLevel != currentLevel) {
      currentLevel = newLevel;

      switch (currentLevel) {
        case 0: // Safe Distance
          lcd.setCursor(0, 1);
          lcd.print("Safe Distance");
          digitalWrite(BUZZER_PIN, LOW); // Turn off buzzer
          sendLineNotify("สถานะปลอดภัย: ระยะห่างคือ " + String(distance) + " ซม.");
          resetNotifyCount(); // Reset all notification counts
          break;

        case 1: // Caution
          if (notifyCount[1] == 0) { // Send notification only once
            lcd.setCursor(0, 1);
            lcd.print("Caution!");
            sendLineNotify("สถานะเตือน: ระยะห่างคือ " + String(distance) + " ซม.");
            notifyCount[1]++;
          }
          digitalWrite(BUZZER_PIN, LOW); // Ensure buzzer is off
          break;

        case 2: // Danger
          if (notifyCount[2] == 0) { // Send notification only once
            lcd.setCursor(0, 1);
            lcd.print("Danger! Too Close");
            sendLineNotify("สถานะอันตราย: ระยะห่างคือ " + String(distance) + " ซม. ใกล้เกินไป!");
            notifyCount[2]++;
          }
          digitalWrite(BUZZER_PIN, HIGH); // Turn on buzzer
          break;
      }
    }

    // Send distance to Blynk
    Blynk.virtualWrite(V0, distance);

    // Debugging in Serial Monitor
    Serial.print("Distance: ");
    Serial.print(distance);
    Serial.println(" cm");
  }
}

void sendToAPI(float distance) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String apiUrl = "https://sandbox.thaikoon.co.th/APITKS/sensor/esp32wokwi";
    http.begin(apiUrl);

    http.addHeader("Content-Type", "application/json");

    // Prepare JSON payload
    String payload = "{\"distance\": " + String(distance) + "}";
    Serial.println("Sending to API: " + payload);

    int httpResponseCode = http.POST(payload);

    if (httpResponseCode > 0) {
      String response = http.getString();
      Serial.println("Response: " + response);
    } else {
      Serial.println("Error sending to API.");
    }

    http.end();
  } else {
    Serial.println("WiFi not connected. Cannot send to API.");
  }
}

void resetNotifyCount() {
  // Reset notification counts for all levels
  for (int i = 0; i < 3; i++) {
    notifyCount[i] = 0;
  }
  Serial.println("Notification counts reset.");
}

void sendLineNotify(String message) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    http.begin("https://notify-api.line.me/api/notify");
    http.addHeader("Content-Type", "application/x-www-form-urlencoded");
    http.addHeader("Authorization", "Bearer " + lineToken);

    String payload = "message=" + message;
    int httpResponseCode = http.POST(payload);

    if (httpResponseCode > 0) {
      Serial.println("LINE Notify Sent!");
    } else {
      Serial.println("Error sending LINE Notify.");
    }

    http.end();
  } else {
    Serial.println("WiFi not connected. Cannot send LINE Notify.");
  }
}