#!/usr/bin/env bash

# AUTHOR: Clemens Schwaighofer
# DATE: 2025/6/27
# DESC: fetch and merge from a remote repositry

REPOSITORY="$1";
BRANCH="$2";
REMOTE_NAME="$3";
if [ "${REPOSITORY}" == "--help" ]; then
	echo "$0 <Repo.git> <branch> [<remote name, defaults to origin>]";
	exit;
fi;
if [ -z "${REMOTE_NAME}" ]; then
	REMOTE_NAME="origin"
fi;
BASE_FOLDER=$(dirname "$(readlink -f "$0")")"/";
# shellcheck source=init.sh
. "${BASE_FOLDER}init.sh";

# check that repository path exists
GIT_REPOSITORY_FOLDER="${GIT_WEBHOOK_BASE_FOLDER}${CLONE_BASE}${REPOSITORY}";
if [ ! -d "${GIT_REPOSITORY_FOLDER}" ]; then
	echo "[!] ${REPOSITORY} not found in clone folder";
	echo "[!] Full path: ${GIT_REPOSITORY_FOLDER}";
	exit;
fi;
LOG_FILE="${GIT_WEBHOOK_BASE_FOLDER}${LOG_FOLDER}${REPOSITORY}.log";
unique_id=$(uuidgen | tr -d '-' | head -c 8);

# fetch to for diff check
GIT_COMMAND=("${GIT_COMMAND_BASE[@]}" "-C" "${GIT_REPOSITORY_FOLDER}" "fetch" "-q" "${REMOTE_NAME}" "${BRANCH}")
"${GIT_COMMAND[@]}"
# check diff for if we need to update
GIT_COMMAND=("${GIT_COMMAND_BASE[@]}" "-C" "${GIT_REPOSITORY_FOLDER}" "diff" "--stat" "HEAD" "${REMOTE_NAME}/${BRANCH}")
# In general all data that should not be checked in should be in the .gitignore file
changes=$("${GIT_COMMAND[@]}" 2>&1)
if [ -n "${changes}" ]; then
	echo "[$(date +"%Y-%m-%d %H:%M:%S")] [${unique_id}] [START] git merge ${GIT_REPOSITORY_FOLDER} ${REMOTE_NAME}/${BRANCH}" &>> "$LOG_FILE";
	# check if there are local changes, make a backup branch and reset them
	local_changes=$("${GIT_COMMAND_BASE[@]}" "-C" "${GIT_REPOSITORY_FOLDER}" "diff" "--quiet");
	cached_changed=$("${GIT_COMMAND_BASE[@]}" "-C" "${GIT_REPOSITORY_FOLDER}" "diff" "--quiet" "--cached");
	if $local_changes || $cached_changed; then
		echo "[$(date +"%Y-%m-%d %H:%M:%S")] [${unique_id}] [!] Local or cached changes detected, creating backup branch and resetting changes" &>> "$LOG_FILE";
		GIT_COMMAND=("${GIT_COMMAND_BASE[@]}" "-C" "${GIT_REPOSITORY_FOLDER}" "branch" "backup-$(date +%Y%m%d-%H%M%S)")
		"${GIT_COMMAND[@]}";
		# Reset everything
		GIT_COMMAND=("${GIT_COMMAND_BASE[@]}" "-C" "${GIT_REPOSITORY_FOLDER}" "reset" "--hard" "HEAD")
		log_data=$("${GIT_COMMAND[@]}" 2>&1);
		echo "[$(date +"%Y-%m-%d %H:%M:%S")] [${unique_id}] Reset log: ${log_data}" &>> "$LOG_FILE";
		GIT_COMMAND=("${GIT_COMMAND_BASE[@]}" "-C" "${GIT_REPOSITORY_FOLDER}" "clean" "-fd")
		log_data=$("${GIT_COMMAND[@]}" 2>&1);
		if [ -n "${log_data}" ]; then
			echo "[$(date +"%Y-%m-%d %H:%M:%S")] [${unique_id}] Clean log: ${log_data}" &>> "$LOG_FILE";
		fi;
	fi;
	# MERGE
	GIT_COMMAND=("${GIT_COMMAND_BASE[@]}" "-C" "${GIT_REPOSITORY_FOLDER}" merge "${REMOTE_NAME}/${BRANCH}")
	log_data=$("${GIT_COMMAND[@]}" 2>&1);
	echo "[$(date +"%Y-%m-%d %H:%M:%S")] [${unique_id}] ${log_data}" &>> "$LOG_FILE";
	echo "[$(date +"%Y-%m-%d %H:%M:%S")] [${unique_id}] [END]" &>> "$LOG_FILE";
fi;

# __END__