void sendTokenRequest(String clientId, String clientSecret, String code) {
  // Replace with your Strava API endpoint
  const char* host = "www.strava.com";
  const int httpsPort = 80;

  // Establish a connection to the server
  WiFiClientSecure client;
  if (!client.connect(host, httpsPort)) {
    Serial.println("Connection failed!");
    return;
  }

  // Create the GET request
  String url = "/oauth/token?client_id=" + clientId + "&client_secret=" + clientSecret + "&code=" + code + "&grant_type=authorization_code";
  
  // Send the HTTP request
  client.print("GET " + url + " HTTP/1.1\r\n");
  client.print("Host: " + String(host) + "\r\n");
  client.print("Connection: close\r\n\r\n");

  Serial.println("Request sent!");

  // Wait for the response
  while (client.connected()) {
    String line = client.readStringUntil('\n');
    if (line == "\r") {
      Serial.println("Headers received");
      break;
    }
  }

  // Print the response
  Serial.println("Response:");

  while (client.available()) {
    char c = client.read();
    Serial.print(c);
  }

  Serial.println();
  
  // Close the connection
  client.stop();
}

/*
//###########POST REQUEST to refresh token#################
void requestRefreshToken(String clientId, String clientSecret, String refreshToken) {
  const char* host = "www.strava.com";
  const int httpsPort = 80;

  WiFiClientSecure client;
  if (!client.connect(host, httpsPort)) {
    Serial.println("Connection failed!");
    return;
  }

  // Create the POST request
  String url = "/oauth/token?client_id=" + clientId + "&client_secret=" + clientSecret + "&refresh_token=" + refreshToken + "&grant_type=refresh_token";

  HTTPClient http;
  http.begin(client, host, httpsPort, url);

  // Send the POST request
  int httpCode = http.POST("");
  if (httpCode > 0) {
    if (httpCode == HTTP_CODE_OK) {
      String payload = http.getString();
      Serial.println("Response: " + payload);

      // Parse JSON response and store tokens
      if (parseJsonResponse(payload)) {
        Serial.println("Tokens retrieved successfully!");
        Serial.println("Access Token: " + accessToken);
        Serial.println("Refresh Token: " + refreshToken);
      } else {
        Serial.println("Failed to parse JSON response!");
      }
    } else {
      Serial.println("HTTP request failed with error code: " + String(httpCode));
    }
  } else {
    Serial.println("HTTP request failed!");
  }

  // Close the connection
  http.end();
}

bool parseJsonResponse(String json) {
  // Parse JSON and extract tokens
  if (json.indexOf("access_token") == -1 || json.indexOf("refresh_token") == -1) {
    Serial.println("JSON does not contain access_token and refresh_token!");
    return false;
  }

  accessToken = getValueFromJson(json, "access_token");
  refreshToken = getValueFromJson(json, "refresh_token");

  return true;
}

String getValueFromJson(String json, String key) {
  int keyIndex = json.indexOf(key);
  if (keyIndex != -1) {
    int startIndex = json.indexOf('"', keyIndex);
    int endIndex = json.indexOf('"', startIndex + 1);
    return json.substring(startIndex + 1, endIndex);
  }

  return "";
}

//###########POST REQUEST to upload the file#################
void uploadActivity(String filename, String access_token) {
  const char* host = "www.strava.com";
  const int httpsPort = 443;

  WiFiClientSecure client;
  if (!client.connect(host, httpsPort)) {
    Serial.println("Connection failed!");
    return;
  }

  // Set the form data
  String formData = "--boundary\r\n"
                    "Content-Disposition: form-data; name=\"activity_type\"\r\n\r\nride\r\n"
                    "--boundary\r\n"
                    "Content-Disposition: form-data; name=\"name\"\r\n\r\nTest Ride\r\n"
                    "--boundary\r\n"
                    "Content-Disposition: form-data; name=\"description\"\r\n\r\nTest description\r\n"
                    "--boundary\r\n"
                    "Content-Disposition: form-data; name=\"trainer\"\r\n\r\n0\r\n"
                    "--boundary\r\n"
                    "Content-Disposition: form-data; name=\"commute\"\r\n\r\n0\r\n"
                    "--boundary\r\n"
                    "Content-Disposition: form-data; name=\"data_type\"\r\n\r\ngpx\r\n"
                    "--boundary\r\n"
                    "Content-Disposition: form-data; name=\"file\"; filename=\"INPUT_RIDE_NUMBER_HERE.gpx\"\r\n"
                    "Content-Type: application/octet-stream\r\n\r\n";

  String endData = "\r\n--boundary--\r\n";

  // Open a connection to the server
  client.println("POST /api/v3/uploads HTTP/1.1");
  client.println("Host: www.strava.com");
  client.println("Authorization: Bearer " + access_token);
  client.println("Content-Type: multipart/form-data; boundary=boundary");
  client.print("Content-Length: ");
  client.println(formData.length() + endData.length());

  // Send the request
  client.print(formData);

  // Open the file and send its contents
  File file = SD.open(filename, FILE_READ);
  if (file) {
    while (file.available()) {
      client.write(file.read());
    }
    file.close();
  }

  client.print(endData);

  // Read and print the response
  while (client.connected()) {
    String line = client.readStringUntil('\n');
    Serial.println(line);
  }

  // Close the connection
  client.stop();
}
*/