R/mfl_connect.R

In ffscrapr: API Client for Fantasy Football League Platforms

#### MFL CONNECT ####

## CONNECT ## ----

#' Connect to MFL League
#'
#' This function creates a connection object which stores parameters and gets a login-cookie if available
#'
#' @param season Season to access on MFL - if missing, will guess based on system date (current year if March or later, otherwise previous year)
#' @param league_id league_id Numeric ID parameter for each league, typically found in the URL
#' @param APIKEY APIKEY - optional - allows access to private leagues. Key is unique for each league and accessible from Developer's API page (currently assuming one league at a time)
#' @param user_name MFL user_name - optional - when supplied in conjunction with a password, will attempt to retrieve authentication token
#' @param password MFL password - optional - when supplied in conjunction with user_name, will attempt to retrieve authentication token
#' @param user_agent A string representing the user agent to be used to identify calls - may find improved rate_limits if verified token
#' @param rate_limit TRUE by default, pass FALSE to turn off rate limiting
#' @param rate_limit_number number of calls per `rate_limit_seconds`, suggested is 60 calls per 60 seconds
#' @param rate_limit_seconds number of seconds as denominator for rate_limit
#' @param ... silently swallows up unused arguments
#'
#' @export mfl_connect
#'
#' @examples
#' \donttest{
#' mfl_connect(season = 2020, league_id = 54040)
#' mfl_connect(season = 2019, league_id = 54040, rate_limit = FALSE)
#' }
#' @return a connection object to be used with `ff_*` functions

mfl_connect <- function(season = NULL,
                        league_id = NULL,
                        APIKEY = NULL,
                        user_name = NULL,
                        password = NULL,
                        user_agent = NULL,
                        rate_limit = TRUE,
                        rate_limit_number = NULL,
                        rate_limit_seconds = NULL,
                        ...) {

  ## USER AGENT ##
  # Self-identifying is mostly about being polite, although MFL has a program to give verified clients more bandwidth!
  # See: https://www03.myfantasyleague.com/2020/csetup?C=APICLI

  if (length(user_agent) > 1) {
    stop("user_agent must be a character vector of length one!")
  }

  if (!is.null(user_agent)) {
    .fn_set_useragent(user_agent)
  }

  ## RATE LIMIT ##
  # For more info, see: https://api.myfantasyleague.com/2020/api_info
  if (!is.logical(rate_limit)) {
    stop("rate_limit should be logical")
  }

  if (!rate_limit ||
    (!is.null(rate_limit_number) & !is.null(rate_limit_number))
  ) {
    .fn_set_ratelimit(rate_limit, "mfl", rate_limit_number, rate_limit_seconds)
  }

  ## SEASON ##
  # MFL organizes things by league year and tends to roll over around February.
  # Sensible default seems to be calling the current year if in March or later,
  # otherwise previous year if in Jan/Feb

  if (is.null(season) || is.na(season)) {
    season <- .fn_choose_season()
    message(glue::glue("No season supplied - choosing {season} based on system date."))
  }

  ## Username/Password Login ##
  m_cookie <- NULL

  if (!is.null(user_name) && is.null(password)) {
    message("User_name supplied but no password - skipping login cookie call!")
  }
  if (!is.null(password) && is.null(user_name)) {
    message("Password supplied but no user_name - skipping login cookie call!")
  }

  if (!is.null(user_name) && !is.null(password)) {
    m_cookie <- .mfl_logincookie(user_name, password, season)
  }

  ## Collect all of the connection pieces and store in an S3 object ##

  structure(
    list(
      platform = "MFL",
      season = season,
      league_id = as.character(league_id),
      APIKEY = APIKEY,
      auth_cookie = m_cookie
    ),
    class = "mfl_conn"
  )
}

## Print Method for Conn Obj ##

#' @noRd
#' @export
print.mfl_conn <- function(x, ...) {
  cat("<MFL connection ", x$season, "_", x$league_id, ">\n", sep = "")
  str(x)
  invisible(x)
}

## LOGIN ## ----
#' Get MFL Login Cookie
#'
#' Gets login cookie for MFL based on user_name/password
#' Docs: https://api.myfantasyleague.com/2020/api_info#login_info
#'
#' @param user_name MFL user_name (as string)
#' @param password MFL password (as string)
#' @param season Season
#'
#' @return a login cookie, which should be included as a parameter in an httr GET request
#'
#' @keywords internal

.mfl_logincookie <- function(user_name, password, season) {
  env <- get(".ffscrapr_env", inherits = TRUE)

  # m_cookie <- env$get(
  #   glue::glue(
  #     "https://api.myfantasyleague.com/{season}/login?",
  #     "USERNAME={user_name}&PASSWORD={utils::URLencode(password,reserved=TRUE)}&XML=1"),
  #   env$user_agent)

  httr::handle_reset("https://api.myfantasyleague.com")

  m_cookie <- env$post(
    url = "https://api.myfantasyleague.com/2020/login",
    body = list(
      USERNAME = user_name,
      PASSWORD = password,
      XML = 1
    ),
    encode = "form",
    env$user_agent
  )

  m_cookie <- purrr::pluck(m_cookie, "cookies", "value")

  if (is.null(m_cookie)) {
    stop("No login cookie available - please recheck user_name/password/season variables again!")
  }

  return(httr::set_cookies("MFL_USER_ID" = m_cookie[[1]], "MFL_PW_SEQ" = m_cookie[[2]]))
}