#!/usr/bin/env bash
# T84: 짧은 시간 안의 다수 설정 변경(annotate)이 debounce에 의해 소수의 push로
# 합쳐지는지 검증. pilot_xds_pushes(타입별 합)뿐 아니라, 메시 전체 연결 프록시 수와
# 무관하게 "병합된 push 사이클" 자체를 세는 pilot_debounce_time_count로 직접 확인한다.
set -euo pipefail

NS="istio-vt-t84"
DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PF_PID=""

cleanup() {
  if [[ -n "${PF_PID}" ]]; then
    kill "${PF_PID}" 2>/dev/null || true
  fi
  kubectl delete namespace "${NS}" --wait=false --ignore-not-found
}
trap cleanup EXIT

kubectl create namespace "${NS}" --dry-run=client -o yaml | \
  kubectl label -f - istio-injection=enabled --local -o yaml | \
  kubectl apply -f -

kubectl apply -f "${DIR}/manifest.yaml"

kubectl -n "${NS}" wait --for=condition=Ready pod/client --timeout=90s
kubectl -n "${NS}" rollout status deploy/echo --timeout=90s

kubectl -n istio-system port-forward deploy/istiod 15014:15014 &
PF_PID=$!
sleep 2

# --- burst 1: as specified by test spec (pilot_xds_pushes, summed across types) ---
BEFORE=$(curl -s localhost:15014/metrics | awk '/^pilot_xds_pushes\{/{s+=$NF} END{print s+0}')
for i in $(seq 1 10); do
  kubectl annotate virtualservice echo-debounce-test -n "${NS}" test-burst="$i" --overwrite
done
sleep 3
AFTER=$(curl -s localhost:15014/metrics | awk '/^pilot_xds_pushes\{/{s+=$NF} END{print s+0}')
echo "before=$BEFORE after=$AFTER delta=$((AFTER-BEFORE))"
echo "(note: this raw delta scales with mesh-wide connected-proxy count x xds-type"
echo " count for a SINGLE merged push, so it is not directly '# of push cycles'.)"

# --- burst 2: direct measurement of merged push-cycle count via pilot_debounce_time_count ---
BEFORE2=$(curl -s localhost:15014/metrics | awk '/^pilot_debounce_time_count/{print $2+0}')
for i in $(seq 1 10); do
  kubectl annotate virtualservice echo-debounce-test -n "${NS}" test-burst2="$i" --overwrite
done
sleep 3
AFTER2=$(curl -s localhost:15014/metrics | awk '/^pilot_debounce_time_count/{print $2+0}')
echo "debounce_before=$BEFORE2 debounce_after=$AFTER2 delta_debounce_events=$((AFTER2-BEFORE2))"

kill "${PF_PID}" 2>/dev/null || true
PF_PID=""