scripts/treno: add script for querying Trenitalia API

scripts/treno

@@ -0,0 +1,201 @@
+#!/bin/sh
+
+print_usage() {
+  cat <<EOF
+Usage: $(basename "$0") [OPTIONS] COMMAND [COMMAND_OPTIONS]
+
+Get information about Trenitalia trains
+
+Options:
+  -h --help                             print this message
+
+Commands:
+
+  search FROM TO [OPTIONS]              search for trains between two stations
+   -i --interactive                     allows selecting a train for more information
+   -d --date DATE                       use DATE instead of now
+
+  status TRAIN_ID [--board STATION]     get realtime information about a train
+   -b --board STATION                   prints the platform number when boarding
+                                        then train from a given station
+EOF
+  exit 1
+}
+
+# Prints realtime information about a train
+train_status() {
+  train="$1"
+  test "$2" = "-b" -o "$2" = "--board" && board_station="$3"
+
+  # Resolve the station name, if necessary
+  if test "${board_station#id:}" = "$board_station"; then
+    board_station=$(station_search "$board_station" | sed 's/^8300/S/g')
+  else
+    board_station=${board_station#id:}
+  fi
+
+  url='http://www.viaggiatreno.it/infomobilita/resteasy/viaggiatreno'
+  today="$(date -d "$(date +%F)" +%s)000"
+  station=$(curl -s "$url/cercaNumeroTrenoTrenoAutocomplete/$1" |
+            grep "$today" | cut -d\| -f2 | cut -d- -f2)
+  curl -s "$url/andamentoTreno/$station/$train/$today" |
+  jq -r --arg board_station "$board_station" '
+    # Functions to color text
+    def red($x):    "\u001B[1;31m\($x)\u001B[0m";
+    def green($x):  "\u001B[1;32m\($x)\u001B[0m";
+    def yellow($x): "\u001B[1;36m\($x)\u001B[0m";
+
+      (if   .tipoTreno == "PG" then green("regolare")
+       elif .tipoTreno == "ST" then red("cancellato")
+       elif .tipoTreno == "DV" then yellow("deviato")
+       elif .tipoTreno == "PP" or
+            .tipoTreno == "SI" or
+            .tipoTreno == "SF" then yellow(.subTitle)
+       else "sconosciuto"
+       end) as $status
+    | (if .nonPartito
+        then []
+        else ["ultima posizione: " + .stazioneUltimoRilevamento
+                                   + "(\(.compOraUltimoRilevamento))"]
+       end) as $position
+    | (if .ritardo <= 0
+         then green(.compRitardo[0])
+         else red(.compRitardo[0])
+       end) as $late
+    | (if $board_station
+        then ["binario arrivo: " +
+          (.fermate[] | select(.id == $board_station)
+                      | .binarioProgrammatoArrivoDescrizione)]
+        else []
+      end) as $platform
+    | ["nome: \(.compNumeroTreno)",
+       "stato: \($status)",
+       "ritardo: \($late)"
+      ] + $platform + $position
+    | join("\n")'
+}
+
+
+# Searches for a station by name and returns its ID
+station_search() {
+  url='https://www.lefrecce.it/Channels.Website.BFF.WEB/website'
+  # URL-encode the search string
+  encoded=$(printf '%s' "$1" | jq -sRr '@uri')
+  curl -s "$url/locations/search?name=$encoded&limit=1" | jq '.[0].id'
+}
+
+
+# Searches for a route between two stations
+route_search() {
+  url='https://www.lefrecce.it/Channels.Website.BFF.WEB/website'
+  query=$(cat <<EOF
+{
+  "departureLocationId": "$1",
+  "arrivalLocationId": "$2",
+  "departureTime": "$(date -d "$3" --iso-8601=s)",
+  "adults": 1,
+  "children": 0,
+  "criteria": {
+    "frecceOnly": false,
+    "regionalOnly": false,
+    "noChanges": false,
+    "order": "DEPARTURE_DATE",
+    "limit": 6,
+    "offset": 0
+  },
+  "advancedSearchRequest": { "bestFare": false }
+}
+EOF
+  )
+
+  printf 'data: \033[36m%s\033[0m\n\n' "$(date -d "$3" +'%F %R')"
+  curl -s --json "$query" "$url/ticket/solutions" |
+  jq -r '
+  "%FT%T.%G%z" as $timefmt |
+
+  # Functions to color text
+  def red($x):    "\u001B[1;31m\($x)\u001B[0m";
+  def green($x):  "\u001B[1;32m\($x)\u001B[0m";
+  def blue($x):   "\u001B[1;34m\($x)\u001B[0m";
+
+  def parse_iso8601:
+    # Parse an ISO 8601 date with timezone information
+    capture("(?<no_tz>[^.]*)(?<frac_sec>\\.\\d+)?(?:(?:(?<tz_sgn>[-+])(?<tz_hr>\\d{2}):?(?<tz_min>\\d{2})?)|Z)$") |
+    (.no_tz + "Z" | fromdateiso8601)
+    + ("0"+.frac_sec | tonumber)
+    - (.tz_sgn + "60" | tonumber)
+    * ((.tz_hr // "0" | tonumber) * 60 + (.tz_min // "0" | tonumber))
+    | todateiso8601 | strptime("%FT%TZ");
+
+  def time:
+    # Extracts "HH:MM" from a timestamp
+    parse_iso8601 | mktime | strftime("%R");
+
+  def delta($stop; $start):
+    # Computes the time elapsed between two dates
+    [$stop, $start]
+    | map(strptime($timefmt) | mktime) # seconds
+    | .[0] - .[1]
+    | ((./60) % 60) as $m
+    | (./3600 | floor) as $h
+    | (if $h > 0 then "\($h)h " else "" end) + "\($m)min";
+
+  def print_trip:
+    # Prints a trip "station(time) → station(time)"
+    (.duration // delta(.arrivalTime; .departureTime)) as $delta |
+    "\(.origin)(\(green(.departureTime | time)))" +
+    " → \(.destination)(\(.arrivalTime | time)) " +
+    blue($delta);
+
+  def print_train:
+    # Prints the train name and its trip
+    "\(.train.description // .train.trainCategory): " + print_trip;
+
+  def print_summary:
+    (.trains | length) as $ntrain |
+    (if $ntrain > 2 then (", " + red("\($ntrain-1) cambi"))
+     elif $ntrain == 2 then (", " + red("1 cambio"))
+     else "" end) as $switch |
+       "- " + print_trip + $switch + "\n  "
+            + (.nodes | map(print_train) | join("\n  "));
+
+  .solutions | map(.solution | print_summary) | join("\n\n")'
+}
+
+handle_search() {
+  # Get station IDs
+  start_id=$(station_search "$1")
+  stop_id=$(station_search "$2")
+  shift 2
+
+  while :; do
+    case "$1" in
+      -d|--date) date=$2; shift ;;
+      -i|--interactive) interactive=1; shift ;;
+      -?*) print_usage ;;
+        *) break
+    esac
+  done
+
+  results=$(route_search "$start_id" "$stop_id" "${date:-now}")
+  printf '%s\n\n' "$results"
+
+  if test -n "$interactive"; then
+    # Ask user to select a train
+    info=$(printf '%s' "$results" | fzf --ansi --no-sort --disabled | cut -d: -f1)
+    # Print the train status
+    train_id=$(printf '%s' "$info" | cut -d: -f1 | rev | cut -d' ' -f 1 | rev)
+    # convert between different API conventions
+    station_id=$(printf '%s' "$start_id" | sed 's/^8300/S/g')
+    train_status "$train_id" --board "id:$station_id"
+  fi
+}
+
+test $# -eq 0 && print_usage
+
+cmd="$1"; shift
+case "$cmd" in
+  search) handle_search "$@" ;;
+  status) train_status "$@" ;;
+       *) print_usage
+esac