From 2626ac2e4800c035d38ef3cf2e58cfb061df5f6e Mon Sep 17 00:00:00 2001
From: Steffen Vogel <steffen.vogel@opal-rt.com>
Date: Thu, 7 Sep 2023 12:26:36 +0200
Subject: [PATCH] Add pre-commit hook for clang-format

Signed-off-by: Steffen Vogel <steffen.vogel@opal-rt.com>
---
 tools/git-pre-commit-hook.sh | 43 ++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 tools/git-pre-commit-hook.sh

diff --git a/tools/git-pre-commit-hook.sh b/tools/git-pre-commit-hook.sh
new file mode 100644
index 000000000..f6237b56a
--- /dev/null
+++ b/tools/git-pre-commit-hook.sh
@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+#
+# Install / run pre-commit hook in repo
+#
+# Author: Steffen Vogel <post@steffenvogel.de>
+# SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
+# SPDX-License-Identifier: Apache-2.0
+
+format_file() {
+  FILE="${1}"
+  if [ -f ${FILE} ]; then
+    if ! clang-format --Werror --dry-run ${FILE}; then
+      clang-format -i ${FILE}
+      return 1
+    fi
+  fi
+}
+
+case "${1}" in
+  help)
+    echo "Run ${0} install to install the git commit hooks"
+    ;;
+
+  install)
+    TOP_DIR=$(git rev-parse --show-toplevel)
+    cp "${BASH_SOURCE[0]}" "${TOP_DIR}/.git/hooks/pre-commit"
+    ;;
+
+  *)
+    FILES=$(git diff-index --cached --name-only HEAD | grep -iE '\.(cpp|hpp|c|h)$')
+    CHANGES=0
+    for FILE in ${FILES}; do
+      if ! format_file "${FILE}"; then
+        CHANGES=$((CHANGES+1))
+      fi
+    done
+
+    if (( ${CHANGES} > 0 )); then
+      echo "Formatting of ${CHANGES} files has been fixed. Please stage and commit again."
+      exit -1
+    fi
+    ;;
+esac