#include <WiFi.h>
#include <ESPmDNS.h>
#include <WiFiUdp.h>
#include <AsyncTCP.h>
#include <ArduinoOTA.h>
#include <ESPAsyncWebServer.h>
#include <WebSerial.h>
#include <HTTPClient.h>
#include <WiFiClientSecure.h>

AsyncWebServer server(80);

// EC200U communication
#define SerialMon Serial       // Debug output to Serial Monitor
#define SerialAT Serial2       // Communication with EC200U

// Define RX2 and TX2 pins for Serial2
#define RX2 16  // Replace with your RX2 pin number
#define TX2 17  // Replace with your TX2 pin number

// Wi-Fi credentials
const char *ssid = "";        // Enter your Wi-Fi SSID
const char *password = "";    // Enter your Wi-Fi password

// HTTP server URL for posting data
const char *serverUrl = "https://roboclubserver.iitd.ac.in/bustracker/update-location/"; // Replace with your server URL

unsigned long lastPublishTime = 0;           // Tracks the last publish time
const unsigned long publishInterval = 10000; // Publish interval (10 seconds)

WiFiClientSecure client;

void setup() {
  // Initialize Serial for debugging
  SerialMon.begin(115200);

  // Initialize Wi-Fi
  SerialMon.println("Booting");
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.waitForConnectResult() != WL_CONNECTED) {
    SerialMon.println("Connection Failed! Rebooting...");
    delay(5000);
    ESP.restart();
  }

  // OTA Setup
  ArduinoOTA
      .onStart([]() {
        String type = (ArduinoOTA.getCommand() == U_FLASH) ? "sketch" : "filesystem";
        Serial.println("Start updating " + type);
      })
      .onEnd([]() {
        Serial.println("\nEnd");
      })
      .onProgress([](unsigned int progress, unsigned int total) {
        Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
      })
      .onError([](ota_error_t error) {
        Serial.printf("Error[%u]: ", error);
        if (error == OTA_AUTH_ERROR) Serial.println("Auth Failed");
        else if (error == OTA_BEGIN_ERROR) Serial.println("Begin Failed");
        else if (error == OTA_CONNECT_ERROR) Serial.println("Connect Failed");
        else if (error == OTA_RECEIVE_ERROR) Serial.println("Receive Failed");
        else if (error == OTA_END_ERROR) Serial.println("End Failed");
      });

  ArduinoOTA.begin();
  SerialMon.println("Ready");
  SerialMon.print("IP address: ");
  SerialMon.println(WiFi.localIP());

  WebSerial.begin(&server);
  WebSerial.msgCallback(recvMsg);
  server.begin();

  // Initialize Serial2 for EC200U communication
  SerialAT.begin(115200, SERIAL_8N1, RX2, TX2);
  delay(1000);

  SerialMon.println("Stopping any existing GPS session...");
  sendATCommand("AT+QGPSEND", "OK", 2000);

  // Start GPS session
  SerialMon.println("Starting GPS...");
  sendATCommand("AT+QGPS=1", "OK", 2000);
  delay(10000);
}

void loop() {
  // Handle OTA updates
  ArduinoOTA.handle();

  // Publish GPS data to the server
  unsigned long currentMillis = millis();
  if (currentMillis - lastPublishTime >= publishInterval) {
    publishData();
    lastPublishTime = currentMillis;
  }
}

void publishData() {
  String gpsData = getGPSData();
  String latitude = "N/A";
  String longitude = "N/A";

  if (gpsData.length() > 0) {
    int comma1 = gpsData.indexOf(",");
    int comma2 = gpsData.indexOf(",", comma1 + 1);
    int comma3 = gpsData.indexOf(",", comma2 + 1);
    if (comma1 != -1 && comma2 != -1) {
      latitude = gpsData.substring(comma1 + 1, comma2);
      longitude = gpsData.substring(comma2 + 1, comma3);
    }
  }

  // Construct the HTTP payload
  String payload = String("{") +
                     "\"device_name\":\"Bus755\"," +
                     "\"latitude\":" + String(latitude, 6) + "," +
                     "\"longitude\":" + String(longitude, 6) +
                     "}";


  // Send the data to the HTTP server
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;

    // Generate a unique parameter (e.g., timestamp or random value) to bypass caching
    String uniqueUrl = String(serverUrl) + "?timestamp=" + String(millis());

    // Use WiFiClientSecure for insecure SSL connections
    http.begin(client, uniqueUrl);  // Pass the insecure WiFiClientSecure client
     // Add root certificate for SSL verification
    http.setInsecure();  // Use this for insecure SSL

    http.addHeader("Content-Type", "application/json");
    http.addHeader("Api-Key", "b52e4585927fbb463db365dae83ac70f17122519");
     // Add custom headers to prevent caching
    http.addHeader("Cache-Control", "no-cache");
    http.addHeader("Pragma", "no-cache");

    int httpResponseCode = http.POST(payload);
    if (httpResponseCode > 0) {
      SerialMon.println("Data sent successfully: " + payload);
      SerialMon.println("Server response: " + http.getString());
    } else {
      SerialMon.println("Error in sending data: " + String(httpResponseCode));
    }
    http.end();
  } else {
    SerialMon.println("Wi-Fi not connected, unable to send data.");
  }
}

void sendATCommand(String command, String response, int timeout) {
  String receivedData;
  SerialAT.println(command); // Send the AT command
  long int time = millis();
  while ((time + timeout) > millis()) {
    while (SerialAT.available()) {
      char c = SerialAT.read(); // Read the response from the module
      receivedData += c;
    }
  }
  if (receivedData.indexOf(response) != -1) {
    SerialMon.println("Received: " + receivedData); // If the response is as expected
    WebSerial.println("Received: " + receivedData);
  } else {
    SerialMon.println("Error");
    WebSerial.println("Error");
  }
}

void recvMsg(uint8_t *data, size_t len) {
  WebSerial.println("Received Data...");
  String d = "";
  for (int i = 0; i < len; i++) {
    d += char(data[i]);
  }
  WebSerial.println(d);
}

String getGPSData() {
  SerialAT.println("AT+QGPSLOC=2\r\n");
  String gpsResponse;
  long int time = millis();
  while ((time + 2000) > millis()) {
    while (SerialAT.available()) {
      char c = SerialAT.read();
      gpsResponse += c;
    }
  }

  int startIndex = gpsResponse.indexOf("+QGPSLOC: ");
  if (startIndex != -1) {
    int endIndex = gpsResponse.indexOf("\r\n", startIndex);
    if (endIndex != -1) {
      String location = gpsResponse.substring(startIndex + 10, endIndex);
      SerialMon.println("GPS Data: " + location);
      WebSerial.println("GPS Data: " + location);
      return location;
    }
  }

  SerialMon.println("Invalid GPS response: " + gpsResponse);
  WebSerial.println("Invalid GPS response: " + gpsResponse);
  return "";
}