#define TINY_GSM_MODEM_SIM800
#define TINY_GSM_RX_BUFFER 256

#include <TinyGPSPlus.h>       
#include <TinyGsmClient.h>     
#include <ArduinoHttpClient.h> 
#include <ArduinoJson.h>       

const char FIREBASE_HOST[] = "tagps-fa005-default-rtdb.firebaseio.com";
const String FIREBASE_AUTH = "TXTe1aAaT8Rlx17eNBf9gZPQOVOClz8ydGGYA0Rd";
const int SSL_PORT = 443;
const String GPS_PATH = "/location";
const String KONTROL_ALAT_PATH = "/kontrol_alat";

char apn[] = "internet";
char user[] = "wap";
char pass[] = "123wap";

#define GSM_RX_PIN 4 
#define GSM_TX_PIN 2 

#define GPS_RX_PIN 16 
#define GPS_TX_PIN 17 

#define RELAY_PIN 26  
#define BUZZER_PIN 27 

HardwareSerial sim800(1);      
TinyGsm modem(sim800);         
HardwareSerial neogps(2);    
TinyGPSPlus gps;               

TinyGsmClientSecure gsm_client_secure_modem(modem, 0); 
HttpClient http_client = HttpClient(gsm_client_secure_modem, FIREBASE_HOST, SSL_PORT);

unsigned long previousMillis = 0; 
const long interval = 10000;     

bool currentRelayState = false;  
bool currentBuzzerState = false; 

void connectToInternet();
void postToFirebase(const char* method, const String & path, const String & data);
bool getKontrolAlat(DynamicJsonDocument &doc);
void handleGPSData();
void controlDevices();

void setup() {
  Serial.begin(115200); 
  Serial.println("ESP32 serial initialize");

  sim800.begin(9600, SERIAL_8N1, GSM_RX_PIN, GSM_TX_PIN); 
  Serial.println("SIM800L serial initialize");

  neogps.begin(9600, SERIAL_8N1, GPS_RX_PIN, GPS_TX_PIN); 
  Serial.println("NeoGPS serial initialize (reading data from actual GPS sensor)");

  delay(3000); 

  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, LOW);

  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);

  Serial.println("Initializing modem...");
  modem.restart(); 

  String modemInfo = modem.getModemInfo(); 
  Serial.print("Modem: ");
  Serial.println(modemInfo);

  connectToInternet(); 
  http_client.setHttpResponseTimeout(30 * 1000); 
}

void loop() {
  if (!modem.isNetworkConnected()) {
    Serial.println("Network disconnected, attempting to reconnect...");
    connectToInternet(); 
  }

  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    handleGPSData();      
    controlDevices();     
  }

  while (neogps.available() > 0) {
    gps.encode(neogps.read());
  }
}

void connectToInternet() {
  Serial.print("Checking signal... ");
  Serial.println(modem.getSignalQuality());

  Serial.print("Checking SIM... ");
  Serial.println(modem.getSimStatus());

  Serial.print("Checking network registration... ");
  Serial.println(modem.isNetworkConnected() ? "Yes" : "No");

  Serial.print("Mencoba terhubung ke APN: ");
  Serial.println(apn);

  int retry_count = 0;
  const int max_retries = 5;

  while (retry_count < max_retries) {
    if (modem.gprsConnect(apn, user, pass)) {
      Serial.println("GPRS connected successfully!");
      return;
    } else {
      Serial.println("GPRS connect failed.");
      retry_count++;
      delay(1000);
    }
  }

  Serial.println("Failed to connect to GPRS after multiple retries.");
}

void postToFirebase(const char* method, const String & path, const String & data) {
  String response;
  int statusCode = 0;

  http_client.connect(FIREBASE_HOST, SSL_PORT);
  if(!http_client.connected()){
    Serial.println("HTTP not connected for POST/PATCH.");
    return; 
  }
  http_client.connectionKeepAlive();

  String url = path + ".json"; 
  url += "?auth=" + FIREBASE_AUTH;

  Serial.print("Method: ");
  Serial.println(method);
  Serial.print("URL: ");
  Serial.println(url);
  Serial.print("Data: ");
  Serial.println(data);

  String contentType = "application/json"; 

  if (strcmp(method, "PATCH") == 0) {
    http_client.patch(url, contentType, data); 
  } else if (strcmp(method, "PUT") == 0) {
    http_client.put(url, contentType, data); 
  } else {
    Serial.println("Unsupported HTTP method for Firebase POST/PATCH.");
    return;
  }

  statusCode = http_client.responseStatusCode(); 
  Serial.print("Status code: ");
  Serial.println(statusCode);
  response = http_client.responseBody(); 
  Serial.print("Response: ");
  Serial.println(response);

  if (!http_client.connected()) {
    Serial.println();
    http_client.stop(); 
    Serial.println("HTTP disconnected after POST/PATCH.");
    if (!modem.isNetworkConnected()) {
      Serial.println("Reconnecting to network after HTTP disconnect...");
      connectToInternet();
    }
  }
}

bool getKontrolAlat(DynamicJsonDocument &doc) {
  String url = KONTROL_ALAT_PATH + ".json";
  url += "?auth=" + FIREBASE_AUTH;

  http_client.connect(FIREBASE_HOST, SSL_PORT); 
  if(!http_client.connected()){
    Serial.println("HTTP not connected for GET.");
    return false;
  }
  http_client.connectionKeepAlive(); 

  Serial.print("GET URL: ");
  Serial.println(url);

  http_client.get(url); 
  int statusCode = http_client.responseStatusCode();
  Serial.print("Status code: ");
  Serial.println(statusCode);

  String response = http_client.responseBody();
  Serial.print("Response: ");
  Serial.println(response);

  if (statusCode == 200) { 
    DeserializationError error = deserializeJson(doc, response);
    if (error) {
      Serial.print(F("deserializeJson() failed: "));
      Serial.println(error.f_str());
      return false; 
    }
    return true; 
  } else {
    if (!http_client.connected()) {
      Serial.println("Reconnecting to network after GET failure...");
      connectToInternet(); 
    }
    return false;
  }
}

void handleGPSData() {
  if (gps.location.isValid()) {
    String latitude = String(gps.location.lat(), 6);
    String longitude = String(gps.location.lng(), 6);

    Serial.print("MENGIRIM DATA GPS ASLI - Latitude= ");
    Serial.print(latitude);
    Serial.print(" Longitude= ");
    Serial.println(longitude);

    String gpsData = "{";
    gpsData += "\"lat\":" + latitude + ",";
    gpsData += "\"lon\":" + longitude + "";
    gpsData += "}";

    postToFirebase("PATCH", GPS_PATH, gpsData);
  } else {
    Serial.println("Waiting for valid GPS data from sensor...");
  }
}

void controlDevices() {
  DynamicJsonDocument doc(256); 
  if (getKontrolAlat(doc)) { 
    if (doc.containsKey("relay")) {
      bool newRelayState = doc["relay"];
      if (newRelayState != currentRelayState) {
        currentRelayState = newRelayState; 
        digitalWrite(RELAY_PIN, currentRelayState ? HIGH : LOW);
        Serial.print("Relay updated from Firebase to ");
        Serial.println(currentRelayState ? "ON" : "OFF");
      }
    } else {
      Serial.println("Firebase path '/kontrol_alat' does not contain 'relay' key.");
    }

    if (doc.containsKey("buzzer")) {
      bool newBuzzerState = doc["buzzer"];
      if (newBuzzerState != currentBuzzerState) {
        currentBuzzerState = newBuzzerState;
        digitalWrite(BUZZER_PIN, newBuzzerState ? HIGH : LOW);
        Serial.print("Buzzer updated from Firebase to ");
        Serial.println(newBuzzerState ? "ON" : "OFF");
      }
    } else {
      Serial.println("Firebase path '/kontrol_alat' does not contain 'buzzer' key.");
    }
  }
}