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

usage() {
  cat <<'USAGE'
Usage: bin/codex-skills-sync.sh [--check|--apply]

Options:
  --check  Prüft Drift zwischen Repo-Skills und ~/.codex/skills (Default)
  --apply  Synchronisiert Repo-Skills nach ~/.codex/skills
USAGE
}

mode="check"
if [[ $# -gt 1 ]]; then
  usage
  exit 2
fi

if [[ $# -eq 1 ]]; then
  case "$1" in
    --check)
      mode="check"
      ;;
    --apply)
      mode="apply"
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      echo "[ERROR] Unknown option: $1" >&2
      usage
      exit 2
      ;;
  esac
fi

if ! command -v rsync >/dev/null 2>&1; then
  echo "[ERROR] rsync is required." >&2
  exit 3
fi

script_dir="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
repo_root="$(cd -- "${script_dir}/.." && pwd)"
source_dir="${repo_root}/tools/codex-skills"
codex_home_dir="${CODEX_HOME:-${HOME}/.codex}"
target_dir="${codex_home_dir}/skills"
managed_skills=(
  "core-guardrails"
  "starterkit-planner"
  "starterkit-grid-standards"
  "starterkit-php-style-ci"
)

for skill in "${managed_skills[@]}"; do
  if [[ ! -d "${source_dir}/${skill}" ]]; then
    echo "[ERROR] Missing source skill: ${source_dir}/${skill}" >&2
    exit 2
  fi
done

check_skill() {
  local skill="$1"
  local src="${source_dir}/${skill}"
  local dst="${target_dir}/${skill}"

  if [[ ! -d "${dst}" ]]; then
    echo "[DRIFT] Missing target skill: ${dst}"
    return 1
  fi

  local diff
  diff="$(diff -qr "${src}" "${dst}" || true)"
  if [[ -n "${diff}" ]]; then
    echo "[DRIFT] ${skill} differs:"
    echo "${diff}" | sed 's/^/  /'
    return 1
  fi

  echo "[OK] ${skill} is in sync"
  return 0
}

apply_skill() {
  local skill="$1"
  local src="${source_dir}/${skill}"
  local dst="${target_dir}/${skill}"

  mkdir -p "${dst}"
  rsync -a --delete "${src}/" "${dst}/"
  echo "[SYNC] ${skill} -> ${dst}"
}

status=0

if [[ "${mode}" == "apply" ]]; then
  mkdir -p "${target_dir}"
  for skill in "${managed_skills[@]}"; do
    apply_skill "${skill}"
  done
fi

for skill in "${managed_skills[@]}"; do
  if ! check_skill "${skill}"; then
    status=1
  fi
done

if [[ ${status} -eq 0 ]]; then
  echo "[OK] codex skill sync check passed"
else
  echo "[FAIL] codex skill sync check found drift"
fi

exit ${status}