#!/bin/bash
# 安裝 git hooks（pre-commit）以執行 clang-format 與可選的 clang-tidy 提示

set -euo pipefail

HOOKS_DIR=".git/hooks"
PRE_COMMIT="$HOOKS_DIR/pre-commit"

if [ ! -d "$HOOKS_DIR" ]; then
  echo "This script must be run inside a Git repository."
  exit 1
fi

cat > "$PRE_COMMIT" <<'EOF'
#!/bin/bash
set -euo pipefail

echo "[pre-commit] Checking/formatting C++ sources..."

# Collect staged C/C++ files
STAGED=$(git diff --cached --name-only --diff-filter=ACMR | grep -E '\.(cpp|cxx|cc|c\+\+|h|hpp|hxx)$' || true)

if [ -z "$STAGED" ]; then
  echo "[pre-commit] No C/C++ files staged."
  exit 0
fi

# 1) clang-format in-place, then re-stage
if command -v clang-format >/dev/null 2>&1; then
  echo "$STAGED" | xargs -r clang-format -i
  echo "$STAGED" | xargs -r git add
else
  echo "[pre-commit] clang-format not found; skipping formatting." >&2
fi

# If formatting changed files, fail once to let user review
CHANGES=$(git diff --name-only --diff-filter=ACMR | grep -E '\\.(cpp|cxx|cc|c\\+\\+|h|hpp|hxx)$' || true)
if [ -n "$CHANGES" ]; then
  echo "[pre-commit] Formatting applied to:"
  echo "$CHANGES"
  echo "[pre-commit] Please review changes and re-commit."
  exit 1
fi

# 2) Optional clang-tidy advisory (Phase 1: do not block commits)
if command -v clang-tidy >/dev/null 2>&1; then
  if [ -f build/compile_commands.json ]; then
    echo "[pre-commit] Running clang-tidy (advisory)..."
    echo "$STAGED" | xargs -r clang-tidy -p build --config-file=.clang-tidy || true
  else
    echo "[pre-commit] No build/compile_commands.json; skip clang-tidy. Run CMake with -DCMAKE_EXPORT_COMPILE_COMMANDS=ON."
  fi
fi

exit 0
EOF

chmod +x "$PRE_COMMIT"
echo "Installed pre-commit hook to $PRE_COMMIT"