#!/usr/bin/env bash
# Verify Git LFS health for this repository.
#
# Why: .gitattributes routes content through the "lfs" filter, but that filter only
# exists after `git lfs install` writes filter.lfs.* into git config. Without it,
# git does NOT fail on a filtered path — it stores the file as an ordinary blob with
# no warning, and the mistake is only noticed later when the file is huge and
# unversioned in LFS. Run this before committing any binary content.
#
# Usage: Tools/check-lfs.sh        (exit 0 = healthy, 1 = problem found)

set -euo pipefail
cd "$(dirname "$0")/.."

fail=0

lfs_patterns=$(grep -c 'filter=lfs' .gitattributes || true)
if [ "${lfs_patterns:-0}" -eq 0 ]; then
  echo "ERROR: .gitattributes has no filter=lfs rules." >&2
  exit 1
fi

if ! command -v git-lfs >/dev/null 2>&1; then
  echo "ERROR: git-lfs is not installed. LFS-tracked files would be stored as ordinary blobs." >&2
  echo "       Install git-lfs, run 'git lfs install', then re-check. See Docs/environment.md." >&2
  fail=1
fi

if ! git config --get filter.lfs.process >/dev/null 2>&1; then
  echo "ERROR: git config has no filter.lfs.process; the lfs filter is not active." >&2
  echo "       Run 'git lfs install' in this repository." >&2
  fail=1
fi

pointer_prefix="version https://git-lfs"
checked=0
while IFS= read -r path; do
  [ -n "$path" ] || continue
  filter=$(git check-attr filter -- "$path" | awk -F': ' '{print $NF}')
  [ "$filter" = "lfs" ] || continue
  checked=$((checked + 1))
  blob_head=$(git cat-file -p ":$path" 2>/dev/null | head -c 64 | tr -d '\0' || true)
  case "$blob_head" in
    "$pointer_prefix"*) ;;
    *)
      echo "ERROR: '$path' is LFS-tracked by .gitattributes but is stored as a plain blob." >&2
      echo "       Fix with: git lfs migrate import --include='$path' (rewrites history)." >&2
      fail=1
      ;;
  esac
done < <(git ls-files)

if [ "$fail" -eq 0 ]; then
  echo "LFS check OK: $checked LFS-tracked file(s) stored as pointers."
fi
exit "$fail"