load departures from given station using deutsche bahn api

departures.sh

#!/usr/bin/env bash
set -euo pipefail

# ----------------------------------------------------------------
# departures.sh — fetch scheduled departures via Timetables 'plan' endpoint only
# Includes ICE, RE, S-Bahn (S), buses, etc.
# Supports filtering by ICE, RE, S and a rolling window in hours
# Deduplicates entries and limits output count
# Adds color highlighting: time (black), train number (red), destination (yellow)
# ----------------------------------------------------------------

# ANSI color codes
BLACK='\033[0;30m'
RED='\033[0;31m'
YELLOW='\033[0;33m'
NC='\033[0m' # No Color

# Base URL for Timetables API
BASE="https://apis.deutschebahn.com/db-api-marketplace/apis/timetables/v1"

# Ensure credentials are set
: "${DB_CLIENT_ID:?Please set DB_CLIENT_ID}"
: "${DB_API_KEY:?Please set DB_API_KEY}"

# Defaults
STATION="Berlin"
FILTER=""        # ICE | RE | S
WINDOW_HOURS=2    # lookahead window (hours)
MAX_ENTRIES=10    # maximum departures to list

# Parse CLI arguments
while [[ $# -gt 0 ]]; do
  case "$1" in
    --station) STATION="$2"; shift 2;;
    --filter)  FILTER="$2";  shift 2;;
    --window)  WINDOW_HOURS="$2"; shift 2;;
    --limit)   MAX_ENTRIES="$2"; shift 2;;
    *) echo "Usage: $0 --station \"Name\" [--filter ICE|RE|S] [--window hours] [--limit count]" >&2; exit 1;;
  esac
done

# URL-encode station name
ENC_STATION=$(python3 -c 'import urllib.parse,sys; print(urllib.parse.quote(sys.argv[1]))' "$STATION")

# 1) Lookup station EVA via XML
echo "🔍 Looking up station: $STATION" >&2
station_xml=$(curl -s \
  -H "Accept: application/xml" \
  -H "DB-Client-Id: $DB_CLIENT_ID" \
  -H "DB-Api-Key:    $DB_API_KEY" \
  "$BASE/station/$ENC_STATION")

eva=$(xmllint --xpath 'string(//station/@eva)' - <<<"$station_xml" 2>/dev/null || echo)
NAME=$(xmllint --xpath 'string(//station/@name)' - <<<"$station_xml" 2>/dev/null || echo)
if [[ -z "$eva" ]]; then
  echo "❌ Station not found: $STATION" >&2
  exit 1
fi
NAME=${NAME:-$STATION}
echo "✅ Station: $NAME (EVA: $eva)" >&2

# 2) Compute time window
t_now=$(date +%s)
if date -v+${WINDOW_HOURS}H >/dev/null 2>&1; then
  t_end=$(date -v+${WINDOW_HOURS}H +%s)
else
  t_end=$(date -d "+${WINDOW_HOURS} hours" +%s)
fi

# 3) Fetch and combine 'plan' for each hour in window
echo "🚉 Fetching schedule for next ${WINDOW_HOURS}h..." >&2
date_tag=$(date '+%y%m%d')
tmpfile=$(mktemp)
echo '<root>' > "$tmpfile"
for ((h=0; h<=WINDOW_HOURS; h++)); do
  if date -v+${h}H >/dev/null 2>&1; then hr=$(date -v+${h}H '+%H'); else hr=$(date -d "+${h} hours" '+%H'); fi
  curl -s \
    -H "Accept: application/xml" \
    -H "DB-Client-Id: $DB_CLIENT_ID" \
    -H "DB-Api-Key:    $DB_API_KEY" \
    "$BASE/plan/$eva/$date_tag/$hr" >> "$tmpfile"
done
echo '</root>' >> "$tmpfile"

# 4) Extract departures and arrivals entries
entries=$(sed 's/<?xml[^>]*>//g' "$tmpfile" \
  | xmlstarlet sel -T -t \
      -m "//s/dp" -v "concat(@pt,'|',@pp,'|',../tl/@c,'|',../tl/@n,'|',@ppth)" -n \
      -m "//s/ar" -v "concat(@pt,'|',@pp,'|',../tl/@c,'|',../tl/@n,'|',@ppth)" -n)
rm "$tmpfile"

# 5) Deduplicate while preserving order
entries=$(printf "%s\n" "$entries" | awk -F'|' '!seen[$1"|"$3"|"$4"|"$5"|"$2]++')

# 6) Output header
echo
echo "📍 Next departures from $NAME (window=${WINDOW_HOURS}h)${FILTER:+, filter $FILTER}:"

# 7) Iterate and display up to MAX_ENTRIES with color
count=0
printf "%s\n" "$entries" | while IFS='|' read -r pt pp cat num path; do
  [[ ! $pt =~ ^[0-9]{10}$ ]] && continue
  [[ -n "$FILTER" && "$cat" != "$FILTER" ]] && continue

  # Parse timestamp
year="20${pt:0:2}"; mon="${pt:2:2}"; day="${pt:4:2}"; hr="${pt:6:2}"; mn="${pt:8:2}"
  ts_fmt="$year-$mon-$day $hr:$mn"
  if date -j >/dev/null 2>&1; then
    epoch=$(date -j -f "%Y-%m-%d %H:%M" "$ts_fmt" +%s)
  else
    epoch=$(date -d "$ts_fmt" +%s)
  fi
  (( epoch < t_now || epoch > t_end )) && continue

  dest="${path##*|}"
  # Color: time=black, train number=red, destination=yellow
  printf "%b - %s %b%s%b to %b%s%b (Platform: %s)\n" \
    "${BLACK}${ts_fmt}${NC}" "$cat" \
    "${RED}" "$num" "${NC}" \
    "${YELLOW}" "$dest" "${NC}" "${pp:-N/A}"
  ((++count>=MAX_ENTRIES)) && break
done