#!/usr/bin/env bash
## ols-htaccess-watcher.sh — graceful-restart the shared OLS when any tenant's
## .htaccess changes. OLS reads .htaccess (RewriteFile) at (re)start, NOT per
## request, so without this a WordPress permalink/LiteSpeed-Cache change would
## silently not take effect. Required by spec 5.3.
##
## Watches all docroots for .htaccess writes, COALESCES bursts (a WP plugin save
## touches the file several times) within a debounce window, and RATE-LIMITS to
## a floor (one restart per FLOOR seconds) so many tenants saving at once can't
## trigger a restart storm. Debounce/floor are env-tunable (panel discloses the
## resulting "~60s" window to customers).
##
## Failure of THIS process is the silent-ticket failure mode (spec 7): if it
## dies, tenants' rewrite changes stop applying with no error. The entrypoint
## runs it and the panel monitors it (check-ols-htaccess-watcher.php).
set -uo pipefail

WATCH_ROOT="${OLS_WATCH_ROOT:-/mnt/users}"
DEBOUNCE="${OLS_HTACCESS_DEBOUNCE:-15}"   # coalesce window (s)
FLOOR="${OLS_HTACCESS_FLOOR:-60}"         # min seconds between restarts
LSWSCTRL=/usr/local/lsws/bin/lswsctrl
last_restart=0

log() { echo "ols-htaccess-watcher: $*" >&2; }

do_restart() {
  now=$(date +%s)
  if [ $((now - last_restart)) -lt "$FLOOR" ]; then
    log "within ${FLOOR}s floor — coalescing, skipping restart"
    return
  fi
  if "$LSWSCTRL" restart >/dev/null 2>&1; then
    last_restart=$now
    log "graceful restart issued (.htaccess change)"
  else
    log "WARNING: lswsctrl restart failed"
  fi
}

if ! command -v inotifywait >/dev/null 2>&1; then
  log "FATAL: inotifywait not installed (inotify-tools)"; exit 1
fi
mkdir -p "$WATCH_ROOT"
log "watching $WATCH_ROOT for .htaccess changes (debounce=${DEBOUNCE}s floor=${FLOOR}s)"

## -m monitor, -r recursive. We filter to .htaccess in the read loop rather than
## --include so this works on older inotify-tools too. modify/create/delete/move
## all matter (delete of .htaccess also changes rewrite behavior).
inotifywait -m -r -e modify,create,delete,move "$WATCH_ROOT" --format '%f' 2>/dev/null |
while read -r fname; do
  case "$fname" in
    .htaccess) ;;
    *) continue ;;
  esac
  ## Drain further events for DEBOUNCE seconds (coalesce the burst), then act.
  while read -r -t "$DEBOUNCE" _; do :; done
  do_restart
done