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

repo_root="$(git rev-parse --show-toplevel)"
cd "${repo_root}"

if ! git diff --quiet --ignore-submodules --; then
  cat <<'EOF' >&2
pre-commit: unstaged tracked changes detected.
Stage or stash tracked changes before committing.
This hook runs repo-level deno fmt and deno lint.
EOF
  exit 1
fi

echo "pre-commit: running deno fmt"
staged_files=()
while IFS= read -r path; do
  if [[ -n "${path}" ]]; then
    staged_files+=("${path}")
  fi
done < <(git diff --cached --name-only --diff-filter=ACMRTUXB)

deno fmt

formatted_files=()
while IFS= read -r path; do
  if [[ -n "${path}" ]]; then
    formatted_files+=("${path}")
  fi
done < <(git diff --name-only --diff-filter=ACMRTUXB)

if (( ${#formatted_files[@]} > 0 )); then
  unrelated_files=()
  for path in "${formatted_files[@]}"; do
    found_in_staged=0
    for staged_path in "${staged_files[@]}"; do
      if [[ "${staged_path}" == "${path}" ]]; then
        found_in_staged=1
        break
      fi
    done

    if (( ! found_in_staged )); then
      unrelated_files+=("${path}")
    fi
  done

  if (( ${#unrelated_files[@]} > 0 )); then
    echo "pre-commit: deno fmt changed tracked files outside the staged set:" >&2
    printf '  %s\n' "${unrelated_files[@]}" >&2
    cat <<'EOF' >&2
Review and stage those formatting changes explicitly, then retry the commit.
EOF
    exit 1
  fi

  git add -- "${formatted_files[@]}"
fi

echo "pre-commit: running deno lint"
deno lint

echo "pre-commit: checks passed"