# Shared metric counters for the media scripts. Sourced, never executed.
#
#   VG_MET_COMPONENT=sweep                      # a plain assignment, NOT a prefix on the next line:
#   . /usr/local/bin/vgmetrics.sh && vgmet_init  # bash discards "VAR=x . file" assignments on return
#   vgmet_add "jobs:encode:done:stream"      # +1
#   vgmet_add "seconds:encode:stream" 41.2   # +41.2
#
# Counters accumulate across runs in MARK/metrics/<component>.counters as plain "key value" lines, and a
# <component>.pid file exists only while the script is executing. dumpd turns both into Prometheus text on
# its /metrics; nothing here renders or serves anything, so the scripts stay simple and there is one place
# that knows the metric names (bin/dumpd.py COUNTER_MAP).
#
# Keys are "name:label:label..." — the name picks the metric, the rest fill its labels in order.
# Writes are atomic (temp file + mv) and every failure is silent: metrics must never break a sweep.

VG_MET_DIR="${VG_MET_DIR:-${MEDIA_ROOT:-/srv/media}/.markers/metrics}"
VG_MET_COMPONENT="${VG_MET_COMPONENT:-$(basename "${0%.sh}")}"
VG_MET_START=0
declare -A VGMET=()

vgmet_init() {
  : "${VG_MET_DIR:=${MEDIA_ROOT:-/srv/media}/.markers/metrics}"
  : "${VG_MET_COMPONENT:=unknown}"
  VG_MET_START=$(date +%s)
  mkdir -p "$VG_MET_DIR" 2>/dev/null || return 0
  local f="$VG_MET_DIR/$VG_MET_COMPONENT.counters" k v
  if [[ -r $f ]]; then
    while read -r k v; do [[ -n ${k:-} && -n ${v:-} ]] && VGMET["$k"]="$v"; done < "$f"
  fi
  vgmet_add runs 1
  printf '%s\n' "$$" > "$VG_MET_DIR/$VG_MET_COMPONENT.pid" 2>/dev/null
  trap vgmet_flush EXIT
}

# vgmet_add <key> [amount]   — float-safe accumulate
vgmet_add() {
  local k="$1" v="${2:-1}"
  VGMET["$k"]=$(awk -v a="${VGMET[$k]:-0}" -v b="$v" 'BEGIN{ printf "%.3f", a+b }')
}

vgmet_set() { VGMET["$1"]="$2"; }

vgmet_flush() {
  : "${VG_MET_DIR:=${MEDIA_ROOT:-/srv/media}/.markers/metrics}"
  : "${VG_MET_COMPONENT:=unknown}"
  local f="$VG_MET_DIR/$VG_MET_COMPONENT.counters" tmp now k
  rm -f "$VG_MET_DIR/$VG_MET_COMPONENT.pid" 2>/dev/null
  [[ -d $VG_MET_DIR ]] || return 0
  now=$(date +%s)
  vgmet_set last_finish "$now"
  vgmet_set last_duration "$(( now - VG_MET_START ))"
  tmp=$(mktemp "$VG_MET_DIR/.$VG_MET_COMPONENT.XXXXXX" 2>/dev/null) || return 0
  for k in "${!VGMET[@]}"; do printf '%s %s\n' "$k" "${VGMET[$k]}"; done > "$tmp" 2>/dev/null
  chmod 0644 "$tmp" 2>/dev/null
  mv -f "$tmp" "$f" 2>/dev/null || rm -f "$tmp" 2>/dev/null
}

# start/elapsed for one job
vgmet_time()  { date +%s.%N; }
vgmet_since() { awk -v s="$1" -v e="$(date +%s.%N)" 'BEGIN{ printf "%.3f", e-s }'; }

# No-op fallbacks are defined by the callers if this file is missing, so a half-finished deploy cannot
# break normalising. Keep every function above failure-tolerant.