From 40e715f84b6e36c98985bbecad15147c32c337fb Mon Sep 17 00:00:00 2001
From: mpadge <mark.padgham@email.com>
Date: Thu, 15 Dec 2022 11:10:19 +0100
Subject: [PATCH] add 'update_trips_table_with_freqs' for #89

---
 DESCRIPTION                   |  2 +-
 R/frequencies_to_stop_times.R | 43 +++++++++++++++++++++++++++++++++++
 codemeta.json                 |  2 +-
 3 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index 5a105f81..1d5a5e6f 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: gtfsrouter
 Title: Routing with GTFS (General Transit Feed Specification) Data
-Version: 0.0.5.129
+Version: 0.0.5.130
 Authors@R: c(
     person("Mark", "Padgham", , "mark.padgham@email.com", role = c("aut", "cre")),
     person("Marcin", "Stepniak", , "marcinstepniak@ucm.es", role = "aut",
diff --git a/R/frequencies_to_stop_times.R b/R/frequencies_to_stop_times.R
index df565a51..090e0519 100644
--- a/R/frequencies_to_stop_times.R
+++ b/R/frequencies_to_stop_times.R
@@ -82,6 +82,8 @@ frequencies_to_stop_times <- function (gtfs) {
     index <- which (names (gtfs_cp$stop_times) %in% names (res))
     gtfs_cp$stop_times <- rbind (gtfs_cp$stop_times [, ..index], res)
 
+    gtfs_cp <- update_trips_table_with_freqs (gtfs_cp, sfx)
+
     attr (gtfs_cp, "freq_sfx") <- sfx
 
     return (gtfs_cp)
@@ -147,3 +149,44 @@ calc_num_new_timetables <- function (freqs) {
 
     return (freqs)
 }
+
+#' Expand each row of "trips" table to corresponding number of new trips with
+#' frequency table extensions of `sfx` + increasing numbers.
+#' @noRd
+update_trips_table_with_freqs <- function (gtfs, sfx) {
+
+    trip_ids <- unique (gtfs$stop_times$trip_id)
+    trip_ids_with_sfx <- grep (paste0 (sfx, "[0-9]*$"), trip_ids, value = TRUE)
+
+    # Current ids in freqs table:
+    freqs_trips <- gsub (paste0 (sfx, "[0-9]*$"), "", trip_ids_with_sfx)
+    freqs_trips_tab <- table (freqs_trips)
+    freqs_trips <- names (freqs_trips_tab)
+    # `freqs_trips` are then the names of the original `trips$trip_id` trips,
+    # with `freqs_trips_tab` tallying how many times each are repeated in
+    # translating the frequencies table.
+
+    index <- which (gtfs$trips$trip_id %in% freqs_trips)
+    if (length (index) == 0) {
+        return (gtfs)
+    }
+
+    trips_no_freqs <- gtfs$trips [seq_len (nrow (gtfs$trips)) [-index], ]
+    trips_freqs <- gtfs$trips [index, ]
+
+    freqs_trips <- freqs_trips [which (freqs_trips %in% trips_freqs$trip_id)]
+    freqs_trips_tab <- freqs_trips_tab [which (names (freqs_trips_tab) %in% trips_freqs$trip_id)]
+
+    # The `trips_freqs` table then has one row for each original trip, with
+    # `trip_id` not containing the `sfx` version for frequency table entries.
+    # Each row needs to be expanded to the corresponding number of
+    # frequency-table trips.
+    freqs_trips_tab <- freqs_trips_tab [match (trips_freqs$trip_id, freqs_trips)]
+    index <- rep (seq_len (nrow (trips_freqs)), times = freqs_trips_tab)
+    trips_freqs_exp <- trips_freqs [index, ]
+    trips_freqs_exp$trip_id <- trip_ids
+
+    gtfs$trips <- rbind (trips_no_freqs, trips_freqs_exp)
+
+    return (gtfs)
+}
diff --git a/codemeta.json b/codemeta.json
index 1a7df694..b801102d 100644
--- a/codemeta.json
+++ b/codemeta.json
@@ -7,7 +7,7 @@
   "codeRepository": "https://github.com/ATFutures/gtfs-router",
   "issueTracker": "https://github.com/ATFutures/gtfs-router/issues",
   "license": "https://spdx.org/licenses/GPL-3.0",
-  "version": "0.0.5.129",
+  "version": "0.0.5.130",
   "programmingLanguage": {
     "@type": "ComputerLanguage",
     "name": "R",