#!/bin/bash

set -euo pipefail

Server_Dir=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
Service_Name="clash-for-linux"
Service_User="${CLASH_SERVICE_USER:-clash}"
Service_Group="${CLASH_SERVICE_GROUP:-$Service_User}"
Unit_Path="/etc/systemd/system/${Service_Name}.service"

if [ "$(id -u)" -ne 0 ]; then
	echo -e "\033[31m[ERROR] 需要 root 权限来安装 systemd 单元\033[0m"
	exit 1
fi

if ! getent group "$Service_Group" >/dev/null 2>&1; then
	groupadd --system "$Service_Group"
fi

if ! id "$Service_User" >/dev/null 2>&1; then
	useradd --system --no-create-home --shell /usr/sbin/nologin --gid "$Service_Group" "$Service_User"
fi

install -d -m 0755 "$Server_Dir/conf" "$Server_Dir/logs" "$Server_Dir/temp"
chown -R "$Service_User:$Service_Group" "$Server_Dir/conf" "$Server_Dir/logs" "$Server_Dir/temp"

cat >"$Unit_Path"<<EOF
[Unit]
Description=Clash for Linux
After=network.target

[Service]
Type=simple
WorkingDirectory=$Server_Dir
ExecStart=/bin/bash $Server_Dir/start.sh
ExecStop=/bin/bash $Server_Dir/shutdown.sh
Restart=on-failure
RestartSec=5
User=$Service_User
Group=$Service_Group
PIDFile=$Server_Dir/temp/clash.pid
Environment=CLASH_ENV_FILE=$Server_Dir/temp/clash-for-linux.sh

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload

echo -e "\033[32m[OK] 已生成 systemd 单元: ${Unit_Path}\033[0m"
echo -e "可执行以下命令启动服务："
echo -e "  sudo systemctl enable --now ${Service_Name}.service"