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

if ! command -v actionlint >/dev/null 2>&1; then
  echo "actionlint not found; install it to validate workflows (e.g., brew install actionlint)." >&2
  exit 1
fi

upstream=$(git rev-parse --abbrev-ref --symbolic-full-name @{u} 2>/dev/null || true)
if [ -n "$upstream" ]; then
  changed=$(git diff --name-only --diff-filter=ACM "$upstream"...HEAD | grep -E '^.github/workflows/.*\.ya?ml$' || true)
else
  changed=$(git diff --name-only --cached --diff-filter=ACM | grep -E '^.github/workflows/.*\.ya?ml$' || true)
fi

if [ -z "$changed" ]; then
  exit 0
fi

actionlint $changed