#!/usr/bin/env bash

set -Eeuo pipefail

WM_DEPLOY_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
# shellcheck source=common.sh
source "$WM_DEPLOY_DIR/scripts/common.sh"
wm_load_env
wm_assert_data_mount

if [[ "$(id -u)" -ne 0 ]]; then
  wm_die "Dieses Skript muss als root ausgeführt werden."
fi

force_rebuild=false
if [[ "${1:-}" == "--force" ]]; then
  force_rebuild=true
  shift
fi
[[ "$#" -eq 0 ]] || wm_die "Unbekannte Argumente für update-route-data.sh."

install -d -m 0755 "$WATERMAPS_RUNTIME_DIR/locks" "$WATERMAPS_DATA_DIR/local"
if [[ "${WATERMAPS_ROUTE_LOCK_HELD:-false}" != "true" ]]; then
  if ! wm_acquire_route_lock; then
    exit 0
  fi
fi

route_file="$(wm_route_file)"
route_marker="$(wm_route_marker)"
route_dir="$(dirname "$route_file")"
candidate_file="$route_dir/.germany-netherlands-fairways.candidate.json"
candidate_marker="$route_dir/.germany-netherlands-fairways.candidate.ready"
backup_file="$route_dir/.germany-netherlands-fairways.previous.json"
backup_marker="$route_dir/.germany-netherlands-fairways.previous.ready"
transaction_file="$WATERMAPS_RUNTIME_DIR/locks/route-update.transaction"
container_candidate="/workspace/data/local/$(basename "$candidate_file")"
container_candidate_marker="/workspace/data/local/$(basename "$candidate_marker")"

transaction_active=false
rollback_restored_previous=false

wm_copy_route_atomically() {
  local source_file="$1"
  local destination_file="$2"
  local temporary_file

  temporary_file="$(mktemp "$(dirname "$destination_file")/.route-copy.XXXXXX")"
  if ! cp --reflink=auto "$source_file" "$temporary_file"; then
    rm -f "$temporary_file"
    return 1
  fi
  chmod 0644 "$temporary_file"
  mv -f "$temporary_file" "$destination_file"
}

wm_watermaps_is_running() {
  [[ -n "$(wm_compose ps --quiet watermaps)" ]]
}

wm_restore_previous_route() {
  rollback_restored_previous=false
  if [[ -s "$backup_file" && -s "$backup_marker" ]] &&
    wm_route_data_files_ready "$backup_file" "$backup_marker"; then
    if ! wm_copy_route_atomically "$backup_file" "$route_file" ||
      ! wm_write_route_marker "$route_file" "$route_marker" ||
      ! wm_route_data_ready; then
      rm -f "$route_file" "$route_marker"
      return 1
    fi
    rollback_restored_previous=true
    return 0
  fi

  rm -f "$route_file" "$route_marker"
  return 1
}

wm_restart_after_restore() {
  if ! wm_watermaps_is_running; then
    wm_log "Watermaps läuft nicht; wiederhergestellte Routingdaten können noch nicht getestet werden."
    return 1
  fi

  wm_compose restart watermaps
  wm_wait_for_health watermaps 240 || return 1
  if [[ "$rollback_restored_previous" == "true" ]]; then
    wm_smoke_test_route
  fi
}

wm_rollback_transaction() {
  local restore_status=0

  if ! wm_restore_previous_route; then
    restore_status=1
  fi
  rm -f "$transaction_file"
  transaction_active=false

  if ! wm_restart_after_restore; then
    return 1
  fi
  return "$restore_status"
}

wm_cleanup_on_exit() {
  local status=$?
  trap - EXIT HUP INT TERM
  set +e

  if [[ "$transaction_active" == "true" ]]; then
    wm_log "Unvollständige Routingaktivierung wird zurückgerollt."
    wm_rollback_transaction
  fi
  rm -f "$candidate_file" "$candidate_marker"
  exit "$status"
}

trap wm_cleanup_on_exit EXIT
trap 'exit 130' HUP INT TERM

# A hard interruption cannot run shell traps. The durable transaction marker
# makes the next invocation restore the last validated index before proceeding.
if [[ -e "$transaction_file" ]]; then
  wm_log "Unterbrochene Routingaktualisierung erkannt; letzter gültiger Stand wird wiederhergestellt."
  if wm_restore_previous_route; then
    wm_restart_after_restore ||
      wm_die "Der wiederhergestellte Routingindex bestand den Routentest nicht."
  else
    wm_restart_after_restore ||
      wm_log "Es existierte noch kein vorheriger Routingindex; aktiver Marker wurde entfernt."
  fi
  rm -f "$transaction_file"
fi

rm -f "$candidate_file" "$candidate_marker"
previous_ready=false
if wm_route_data_ready; then
  previous_ready=true
  if [[ "$force_rebuild" != "true" ]]; then
    cp --reflink=auto "$route_file" "$candidate_file"
    chmod 0644 "$candidate_file"
  fi
fi

wm_log "Deutschland-/Niederlande-Routingdaten werden in einer Stagingdatei gebaut."
if ! wm_compose --profile maintenance run --rm --build \
  --env "WATERMAPS_LOCAL_FAIRWAYS_PATH=$container_candidate" \
  --env "WATERMAPS_ROUTE_MARKER_PATH=$container_candidate_marker" \
  route-data; then
  wm_die "Der Datenaufbau ist fehlgeschlagen; der aktive Index wurde nicht verändert."
fi

if ! wm_route_data_files_ready "$candidate_file" "$candidate_marker"; then
  wm_die "Der neu gebaute Routingindex oder sein Bereitschaftsmarker ist ungültig."
fi

if [[ "$previous_ready" == "true" ]] && cmp --silent "$candidate_file" "$route_file"; then
  wm_log "Geofabrik-Snapshots und Routingindex sind unverändert."
  rm -f "$candidate_file" "$candidate_marker"
  exit 0
fi

if [[ "$previous_ready" == "true" ]]; then
  wm_copy_route_atomically "$route_file" "$backup_file"
  wm_write_route_marker "$backup_file" "$backup_marker"
  wm_route_data_files_ready "$backup_file" "$backup_marker" ||
    wm_die "Der bisherige Routingindex konnte nicht sicher gesichert werden."
else
  rm -f "$backup_file" "$backup_marker"
fi

temporary_transaction="$(mktemp "$WATERMAPS_RUNTIME_DIR/locks/.route-update-transaction.XXXXXX")"
{
  printf 'started_at=%s\n' "$(date --utc +%Y-%m-%dT%H:%M:%SZ)"
  printf 'had_previous=%s\n' "$previous_ready"
} >"$temporary_transaction"
chmod 0644 "$temporary_transaction"
mv -f "$temporary_transaction" "$transaction_file"
transaction_active=true

mv -f "$candidate_file" "$route_file"
rm -f "$candidate_marker"
wm_write_route_marker "$route_file" "$route_marker"
wm_route_data_ready ||
  wm_die "Der aktivierte Routingindex besitzt keinen gültigen Bereitschaftsmarker."

wm_compose restart watermaps
if wm_wait_for_health watermaps 240 && wm_smoke_test_route; then
  rm -f "$transaction_file"
  transaction_active=false
  rm -f "$backup_file" "$backup_marker"
  wm_log "Routingdaten-Update wurde erfolgreich aktiviert."
  exit 0
fi

wm_log "Der neue Routingindex bestand die Routentests nicht; Rollback wird ausgeführt."
if wm_rollback_transaction; then
  rm -f "$backup_file" "$backup_marker"
  wm_die "Neuer Routingindex verworfen; der vorherige, erneut getestete Index ist aktiv."
fi

if [[ "$rollback_restored_previous" == "true" ]]; then
  wm_die "Rollback-Dateien wurden wiederhergestellt, bestanden aber den Routentest nicht."
fi
wm_die "Neuer Routingindex verworfen; es existierte noch kein vorheriger gültiger Index."