From fd280b1ee6e5586158881959134d8ed809a9c229 Mon Sep 17 00:00:00 2001
From: mrcaseb <38586519+mrcaseb@users.noreply.github.com>
Date: Tue, 19 Sep 2023 04:35:47 +0200
Subject: [PATCH] Latest season with labor day (#221)

`most_recent_season()` now internally computes the exact day of the
season opener (= Thursday after first Monday of September).
---
 DESCRIPTION          |  2 +-
 NEWS.md              |  1 +
 R/utils_date.R       | 32 +++++++++++++++++++++++++++++---
 man/latest_season.Rd |  5 ++++-
 4 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index f4644ffd..e4a3847b 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: nflreadr
 Title: Download 'nflverse' Data
-Version: 1.4.0.04
+Version: 1.4.0.05
 Authors@R: c(
     person("Tan", "Ho", , "tan@tanho.ca", role = c("aut", "cre", "cph"),
            comment = c(ORCID = "0000-0001-8388-5155")),
diff --git a/NEWS.md b/NEWS.md
index ee262d38..731eae5f 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -5,6 +5,7 @@
 - `%c%` internal helper now uses `data.table::fifelse()` to avoid falsely converting dates to integers. (#214)
 - `load_schedules()` cleans the `roof` variable in order to avoid nflverse model issues. (#218)
 - `join_coalesce()` coerces x/y args to data.frame and will return a data.frame
+- `most_recent_season()` now internally computes the exact day of the season opener (= Thursday after first Monday of September). (#221)
 
 ---
 
diff --git a/R/utils_date.R b/R/utils_date.R
index ece65254..32ffedf5 100644
--- a/R/utils_date.R
+++ b/R/utils_date.R
@@ -2,8 +2,10 @@
 #'
 #' A helper function to choose the most recent season available for a given dataset
 #'
-#' @param roster a TRUE/FALSE flag: if TRUE, returns the current year if March 15th or later. if FALSE, returns the current year if September 1st or later. Otherwise returns current year minus 1.
-#'
+#' @param roster Either `TRUE` or `FALSE`.
+#' If `TRUE`, will return current year after March 15th, otherwise previous year.
+#' If `FALSE`, will return current year on or after Thursday following Labor Day,
+#' i.e. Thursday after the first Monday in September. Otherwise previous year.
 #'
 #' @rdname latest_season
 #' @return most recent season (a four digit numeric)
@@ -14,8 +16,12 @@ most_recent_season <- function(roster = FALSE) {
   current_year <- as.integer(format(today, format = "%Y"))
   current_month <- as.integer(format(today, format = "%m"))
   current_day <- as.integer(format(today, format = "%d"))
+  # First Monday of September
+  labor_day <- compute_labor_day(current_year)
+  # Thursday following Labor Day is TNF season opener
+  season_opener <- labor_day + 3
 
-  if ((isFALSE(roster) && current_month >= 9) ||
+  if ((isFALSE(roster) && today >= season_opener) ||
       (isTRUE(roster) && current_month == 3 && current_day >= 15) ||
       (isTRUE(roster) && current_month > 3 )) {
 
@@ -93,3 +99,23 @@ get_current_week <- function(use_date = FALSE) {
     return(current_week)
   }
 }
+
+#' Compute Date of Labor Day
+#'
+#' Computes the date of the Labor Day, i.e. the first Monday in September, in a given year.
+#'
+#' @param year Numeric or Character year. 4 Digits.
+#' @noRd
+#' @return Object of Class `Date`
+#' @examples
+#' # 2023 Labor Day was on Sep 4th
+#' compute_labor_day(2023)
+compute_labor_day <- function(year){
+  stopifnot(length(year) == 1)
+  earliest <- as.Date(paste(year, "09", "01", sep = "-"))
+  latest <- as.Date(paste(year, "09", "08", sep = "-"))
+  range <- seq(earliest, latest, by = "day")
+  numeric_wdays <- as.POSIXlt(range)$wday
+  labor_day <- range[numeric_wdays == 1][1]
+  labor_day
+}
diff --git a/man/latest_season.Rd b/man/latest_season.Rd
index 4b06d03a..ffef94ad 100644
--- a/man/latest_season.Rd
+++ b/man/latest_season.Rd
@@ -13,7 +13,10 @@ get_latest_season(roster = FALSE)
 get_current_season(roster = FALSE)
 }
 \arguments{
-\item{roster}{a TRUE/FALSE flag: if TRUE, returns the current year if March 15th or later. if FALSE, returns the current year if September 1st or later. Otherwise returns current year minus 1.}
+\item{roster}{Either \code{TRUE} or \code{FALSE}.
+If \code{TRUE}, will return current year after March 15th, otherwise previous year.
+If \code{FALSE}, will return current year on or after Thursday following Labor Day,
+i.e. Thursday after the first Monday in September. Otherwise previous year.}
 }
 \value{
 most recent season (a four digit numeric)