#!/usr/bin/env bash
set -euo pipefail

log() {
  printf '[bench-create] %s\n' "$*" >&2
}

usage() {
  cat <<'EOF'
Usage: ./scripts/bench-create.sh [--runs N] [--image NAME] [--keep]

Measures:
  - create_ms: time for `banger vm create`
  - ssh_ready_ms: time until `banger vm ssh <vm> -- true` succeeds
EOF
}

RUNS=5
IMAGE_NAME=""
KEEP=0

while [[ $# -gt 0 ]]; do
  case "$1" in
    --runs)
      RUNS="${2:-}"
      shift 2
      ;;
    --image)
      IMAGE_NAME="${2:-}"
      shift 2
      ;;
    --keep)
      KEEP=1
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      log "unknown option: $1"
      usage
      exit 1
      ;;
  esac
done

if ! [[ "$RUNS" =~ ^[0-9]+$ ]] || [[ "$RUNS" -le 0 ]]; then
  log "--runs must be a positive integer"
  exit 1
fi

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
BANGER_BIN="${BANGER_BIN:-$REPO_ROOT/banger}"
if [[ ! -x "$BANGER_BIN" ]]; then
  log "banger binary not found: $BANGER_BIN"
  log "run 'make build' or set BANGER_BIN"
  exit 1
fi

timestamp_ms() {
  date +%s%3N
}

json_escape() {
  python3 - <<'PY' "$1"
import json, sys
print(json.dumps(sys.argv[1]))
PY
}

printf '[\n'
for run in $(seq 1 "$RUNS"); do
  vm_name="bench-$(date +%s)-$run"
  create_args=("$BANGER_BIN" vm create --name "$vm_name")
  if [[ -n "$IMAGE_NAME" ]]; then
    create_args+=(--image "$IMAGE_NAME")
  fi

  create_start="$(timestamp_ms)"
  if ! "${create_args[@]}" >/dev/null; then
    log "create failed for $vm_name"
    exit 1
  fi
  create_end="$(timestamp_ms)"

  ssh_start="$create_end"
  ssh_ready=0
  deadline=$((ssh_start + 60000))
  while (( $(timestamp_ms) < deadline )); do
    if "$BANGER_BIN" vm ssh "$vm_name" -- true >/dev/null 2>&1; then
      ssh_ready="$(timestamp_ms)"
      break
    fi
    sleep 0.5
  done
  if [[ "$ssh_ready" -eq 0 ]]; then
    log "ssh did not become ready for $vm_name"
    exit 1
  fi

  if [[ "$KEEP" -ne 1 ]]; then
    "$BANGER_BIN" vm delete "$vm_name" >/dev/null || true
  fi

  printf '  {"run": %d, "vm_name": %s, "create_ms": %d, "ssh_ready_ms": %d}%s\n' \
    "$run" \
    "$(json_escape "$vm_name")" \
    "$((create_end - create_start))" \
    "$((ssh_ready - create_start))" \
    "$( [[ "$run" -lt "$RUNS" ]] && printf ',' )"
done
printf ']\n'