#!/bin/sh
set -eu
umask 077

ROOT=$(CDPATH='' cd -- "$(dirname -- "$0")/.." && pwd)
# shellcheck source=scripts/scale-common.sh
. "$ROOT/scripts/scale-common.sh"
scale_load_environment

K6_IMAGE="grafana/k6@sha256:65c920dc067d5e2e00befbf982af6ad6ad0117034e8b1c65817c7975c52d4669"
STATE_FILE=${WNH_SCALE_BROWSER_STATE:-"$ROOT/output/runtime/scale-browser-state.json"}
VUS=${WNH_SCALE_READONLY_VUS:?WNH_SCALE_READONLY_VUS is required}
DURATION=${WNH_SCALE_READONLY_DURATION:?WNH_SCALE_READONLY_DURATION is required}
THINK_SECONDS=${WNH_SCALE_READONLY_THINK_SECONDS:?WNH_SCALE_READONLY_THINK_SECONDS is required}
LABEL=${WNH_SCALE_READONLY_LABEL:-"scale-readonly-$(date -u +%Y%m%dT%H%M%SZ)"}
OUTPUT_DIR="$ROOT/output/performance/$LABEL"

case "$VUS" in
  ''|*[!0-9]*|0)
    echo "WNH_SCALE_READONLY_VUS must be a positive integer." >&2
    exit 2
    ;;
esac

if ! printf '%s\n' "$DURATION" | grep -Eq '^[1-9][0-9]*(ms|s|m|h)$'; then
  echo "WNH_SCALE_READONLY_DURATION must be a positive k6 duration." >&2
  exit 2
fi

if ! printf '%s\n' "$THINK_SECONDS" |
  grep -Eq '^([0-9]+([.][0-9]+)?|[.][0-9]+)$'; then
  echo "WNH_SCALE_READONLY_THINK_SECONDS must be a non-negative number." >&2
  exit 2
fi

case "$LABEL" in
  ''|*[!A-Za-z0-9._-]*)
    echo "WNH_SCALE_READONLY_LABEL contains unsupported characters." >&2
    exit 2
    ;;
esac

if [ ! -f "$STATE_FILE" ]; then
  echo "Missing authenticated scale browser state: $STATE_FILE" >&2
  exit 2
fi

session_cookie=$(
  jq -r '
    .cookies[]
    | select(.domain == "scale.localhost" and .name == "_who_need_help_key")
    | "\(.name)=\(.value)"
  ' "$STATE_FILE"
)

if [ -z "$session_cookie" ]; then
  echo "The browser state does not contain the scale session cookie." >&2
  exit 2
fi

web_id=$(scale_compose ps -q web)
worker_id=$(scale_compose ps -q worker)
db_id=$(scale_compose ps -q db)

for pair in "web:$web_id" "worker:$worker_id" "db:$db_id"; do
  service=${pair%%:*}
  container=${pair#*:}

  if [ -z "$container" ] || [ "$(docker inspect --format '{{.State.Status}}' "$container")" != "running" ]; then
    echo "Scale service $service is not running." >&2
    exit 2
  fi
done

actual_database=$(
  scale_compose exec -T db \
    psql -XAt -U "$POSTGRES_USER" -d "$POSTGRES_DB" \
    -c 'SELECT current_database()'
)

if [ "$actual_database" != "$WNH_SCALE_EXPECTED_DATABASE" ]; then
  echo "Refusing unexpected database: $actual_database" >&2
  exit 2
fi

if [ -e "$OUTPUT_DIR" ]; then
  echo "Output path already exists: $OUTPUT_DIR" >&2
  exit 2
fi

mkdir -p "$OUTPUT_DIR"
chmod 700 "$ROOT/output" "$ROOT/output/performance" "$OUTPUT_DIR"

snapshot_counts() {
  destination=$1

  scale_compose exec -T db \
    psql -XAt -U "$POSTGRES_USER" -d "$POSTGRES_DB" \
    -c "
      SELECT json_build_object(
        'captured_at', clock_timestamp(),
        'database', current_database(),
        'users', (SELECT count(*) FROM users),
        'users_tokens', (SELECT count(*) FROM users_tokens),
        'help_requests', (SELECT count(*) FROM help_requests),
        'activities', (SELECT count(*) FROM activities),
        'help_assignments', (SELECT count(*) FROM help_assignments),
        'activity_participants', (SELECT count(*) FROM activity_participants),
        'messages', (SELECT count(*) FROM messages),
        'activity_messages', (SELECT count(*) FROM activity_messages),
        'rate_limit_buckets', (SELECT count(*) FROM rate_limit_buckets)
      )
    " >"$destination"
}

snapshot_counts "$OUTPUT_DIR/counts-before.json"

cat >"$OUTPUT_DIR/scope.txt" <<EOF
target=http://web:4000
host_header=scale.localhost
compose_project=$LOAD_PROJECT
database=$actual_database
database_volume=${LOAD_PROJECT}_postgres_data
cpuset=$CPU_REPLAY_CPUSET
vus=$VUS
duration=$DURATION
think_seconds=$THINK_SECONDS
scope=authenticated GET-only static LiveView shells; discovery SQL is measured separately by scripts/scale-verify.sh
mutating_routes=false
test_or_production_targets=false
latency_or_capacity_thresholds_applied=false
EOF

docker run --rm \
  --user "$(id -u):$(id -g)" \
  --cpuset-cpus "$CPU_REPLAY_CPUSET" \
  --network "${LOAD_PROJECT}_internal" \
  --env BASE_URL=http://web:4000 \
  --env "SESSION_COOKIE=$session_cookie" \
  --env "VUS=$VUS" \
  --env "DURATION=$DURATION" \
  --env "THINK_SECONDS=$THINK_SECONDS" \
  --volume "$ROOT/load/k6:/scripts:ro" \
  --volume "$OUTPUT_DIR:/output" \
  "$K6_IMAGE" run \
  --summary-export /output/k6-summary.json \
  /scripts/scale-readonly.js

snapshot_counts "$OUTPUT_DIR/counts-after.json"

jq -e '
  del(.captured_at) as $before
  | $before == (input | del(.captured_at))
' "$OUTPUT_DIR/counts-before.json" "$OUTPUT_DIR/counts-after.json" >/dev/null

docker run --rm \
  --volume "$OUTPUT_DIR:/output" \
  alpine:3.23.3@sha256:25109184c71bdad752c8312a8623239686a9a2071e8825f20acb8f2198c3f659 \
  chown -R "$(id -u):$(id -g)" /output

printf 'Read-only scale result: %s\n' "$OUTPUT_DIR"