# shared helpers for S3c bench (no secrets)
set -euo pipefail

log() { printf '[%s] %s\n' "$(date '+%Y-%m-%dT%H:%M:%S%z')" "$*"; }

parse_mem_mib() {
  python3 - "$1" <<'PY'
import re, sys
s = sys.argv[1].split("/")[0].strip()
m = re.match(r"([0-9.]+)\s*([A-Za-z]+)", s)
if not m:
    print("0")
    raise SystemExit
v, u = float(m.group(1)), m.group(2).lower()
mult = {"b":1,"kib":1024,"kb":1000,"mib":1024**2,"mb":1000**2,"gib":1024**3,"gb":1000**3}.get(u)
if not mult:
    print("0"); raise SystemExit
print(f"{v * mult / (1024**2):.3f}")
PY
}

cgroup_mib() {
  local c="$1" raw=""
  raw="$(docker exec "$c" sh -c 'cat /sys/fs/cgroup/memory.current 2>/dev/null || cat /sys/fs/cgroup/memory/memory.usage_in_bytes 2>/dev/null' 2>/dev/null || true)"
  if [[ -z "$raw" ]]; then
    echo ""
    return
  fi
  python3 -c "print(f'{int(\"$raw\")/(1024*1024):.3f}')"
}

sample_stats() {
  # sample_stats <out.tsv> <interval_s> <duration_s> <container...>
  local out="$1" interval="$2" duration="$3"
  shift 3
  mkdir -p "$(dirname "$out")"
  echo -e "ts_iso\tname\tmem_usage\tcpu_pct\tmem_mib\tcgroup_mib" > "$out"
  local end=$(( $(date +%s) + duration ))
  while [ "$(date +%s)" -lt "$end" ]; do
    local ts
    ts=$(date -u +%Y-%m-%dT%H:%M:%SZ)
    local line name mem cpu
    while IFS='|' read -r name mem cpu; do
      [[ -z "${name:-}" ]] && continue
      local mib cg
      mib="$(parse_mem_mib "$mem")"
      cg="$(cgroup_mib "$name")"
      printf '%s\t%s\t%s\t%s\t%s\t%s\n' "$ts" "$name" "$mem" "$cpu" "$mib" "${cg:-}" >> "$out"
    done < <(docker stats --no-stream --format '{{.Name}}|{{.MemUsage}}|{{.CPUPerc}}' "$@" 2>/dev/null || true)
    sleep "$interval"
  done
}

sample_until_file() {
  # sample until a sentinel file exists, then extra_s more
  local out="$1" interval="$2" sentinel="$3" extra_s="$4"
  shift 4
  mkdir -p "$(dirname "$out")"
  echo -e "ts_iso\tname\tmem_usage\tcpu_pct\tmem_mib\tcgroup_mib" > "$out"
  while [[ ! -f "$sentinel" ]]; do
    local ts name mem cpu mib cg
    ts=$(date -u +%Y-%m-%dT%H:%M:%SZ)
    while IFS='|' read -r name mem cpu; do
      [[ -z "${name:-}" ]] && continue
      mib="$(parse_mem_mib "$mem")"
      cg="$(cgroup_mib "$name")"
      printf '%s\t%s\t%s\t%s\t%s\t%s\n' "$ts" "$name" "$mem" "$cpu" "$mib" "${cg:-}" >> "$out"
    done < <(docker stats --no-stream --format '{{.Name}}|{{.MemUsage}}|{{.CPUPerc}}' "$@" 2>/dev/null || true)
    sleep "$interval"
  done
  local end=$(( $(date +%s) + extra_s ))
  while [ "$(date +%s)" -lt "$end" ]; do
    local ts name mem cpu mib cg
    ts=$(date -u +%Y-%m-%dT%H:%M:%SZ)
    while IFS='|' read -r name mem cpu; do
      [[ -z "${name:-}" ]] && continue
      mib="$(parse_mem_mib "$mem")"
      cg="$(cgroup_mib "$name")"
      printf '%s\t%s\t%s\t%s\t%s\t%s\n' "$ts" "$name" "$mem" "$cpu" "$mib" "${cg:-}" >> "$out"
    done < <(docker stats --no-stream --format '{{.Name}}|{{.MemUsage}}|{{.CPUPerc}}' "$@" 2>/dev/null || true)
    sleep "$interval"
  done
}

ensure_image() {
  # ensure_image <ref> <note_file>
  local img="$1" note="${2:-}"
  local platform="linux/arm64"
  local how="local"
  if docker image inspect "$img" >/dev/null 2>&1; then
    local arch
    arch="$(docker image inspect --format '{{.Architecture}}' "$img")"
    if [[ "$arch" == "arm64" || "$arch" == "arm64/v8" ]]; then
      log "image present $img arch=$arch"
      [[ -n "$note" ]] && echo "$how" > "$note"
      return 0
    fi
    log "image $img arch=$arch not arm64; re-pull"
  fi
  log "docker pull --platform $platform $img"
  if docker pull --platform "$platform" "$img"; then
    how="hub"
    [[ -n "$note" ]] && echo "$how" > "$note"
    return 0
  fi
  local short="${img#docker.io/}"
  local mirror="docker.m.daocloud.io/${short}"
  log "primary pull failed; retry $mirror"
  docker pull --platform "$platform" "$mirror"
  docker tag "$mirror" "$img"
  how="daocloud_mirror"
  [[ -n "$note" ]] && echo "$how" > "$note"
}

image_meta() {
  local c="$1"
  docker inspect --format '{{.Config.Image}} {{index .RepoDigests 0}} {{.Image}}' "$c" 2>/dev/null || true
}

wait_http() {
  local url="$1" tries="${2:-40}"
  local i
  for i in $(seq 1 "$tries"); do
    if curl -sf --max-time 2 "$url" >/dev/null; then
      return 0
    fi
    sleep 1
  done
  return 1
}