#!/usr/bin/env bash
set -euo pipefail
if [ "${1:-}" = "--help" ] || [ "${1:-}" = "-h" ]; then
  cat <<'USAGE'
Purpose: Validate ux-state-machine output. 3 sections; Transitions table
         present with canonical 4-column header.
Usage:   bash scripts/lint-output.sh <file>   (or stdin)
USAGE
  exit 0
fi
if [ "${1:-}" = "" ] || [ "${1:-}" = "-" ]; then body=$(cat)
elif [ -f "$1" ]; then body=$(cat "$1")
else printf 'error: file not found: %s\n' "$1" >&2; exit 2
fi

issues=0
say() { printf '%s\n' "$1" >&2; issues=$((issues+1)); }

for h in '## State Inventory' '## Transitions'; do
  grep -qE "^${h}\$" <<<"$body" || say "missing \"${h}\""
done
grep -qE '(^## Gaps|^Gaps: none$)' <<<"$body" || say 'missing "## Gaps" or exact "Gaps: none"'
grep -qE '^\| From \| Trigger \| To \| Notes \|' <<<"$body" || say 'Transitions missing canonical 4-column header'

[ "$issues" -gt 0 ] && exit 1
printf 'ok\n'