#!/bin/bash

VERSION="v5.0.1"
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
BLUE='\033[0;34m'
PURPLE='\033[0;35m'
CYAN='\033[0;36m'
RESET='\033[0m'

get_system_type() {
    if [ -f /etc/debian_version ]; then
        echo "debian"
    elif [ -f /etc/redhat-release ]; then
        echo "centos"
    elif [ -f /etc/arch-release ]; then
        echo "archlinux"
    else
        echo "unknown"
    fi
}

wait_for_package_manager() {
    local system_type=$(get_system_type)
    if [ "$system_type" = "debian" ]; then
        while fuser /var/lib/dpkg/lock >/dev/null 2>&1 || fuser /var/lib/apt/lists/lock >/dev/null 2>&1 || fuser /var/cache/apt/archives/lock >/dev/null 2>&1; do
            echo -e "${YELLOW}等待其他 apt 进程完成${RESET}"
            sleep 1
        done
    fi
}

install_required_packages() {
    local system_type=$(get_system_type)
    echo -e "${GREEN}安装必要软件包${RESET}"
    
    if [ "$system_type" = "debian" ]; then
        apt update
        apt install -y wget unzip curl
    elif [ "$system_type" = "centos" ]; then
        yum -y update
        yum -y install wget unzip curl
    elif [ "$system_type" = "archlinux" ]; then
        pacman -Sy
        pacman -S wget unzip curl
    else
        echo -e "${RED}不支持的系统类型${RESET}"
        exit 1
    fi
}

check_root() {
    if [ "$(id -u)" != "0" ]; then
        echo -e "${RED}请以 root 权限运行此脚本.${RESET}"
        exit 1
    fi
}

check_snell_installed() {
    if command -v snell-server &> /dev/null; then
        return 0
    else
        return 1
    fi
}

check_snell_running() {
    systemctl is-active --quiet "snell.service"
    return $?
}

start_snell() {
    systemctl start "snell.service"
    if [ $? -eq 0 ]; then
        echo -e "${GREEN}Snell 启动成功${RESET}"
    else
        echo -e "${RED}Snell 启动失败${RESET}"
    fi
}

stop_snell() {
    systemctl stop "snell.service"
    if [ $? -eq 0 ]; then
        echo -e "${GREEN}Snell 停止成功${RESET}"
    else
        echo -e "${RED}Snell 停止失败${RESET}"
    fi
}

install_snell() {
    echo -e "${GREEN}正在安装 Snell${RESET}"

    wait_for_package_manager
    install_required_packages || {
        echo -e "${RED}安装必要软件包失败${RESET}"
        exit 1
    }

    ARCH=$(arch)
    if [[ ${ARCH} == "aarch64" ]]; then
        SNELL_URL="https://dl.nssurge.com/snell/snell-server-${VERSION}-linux-aarch64.zip"
    else
        SNELL_URL="https://dl.nssurge.com/snell/snell-server-${VERSION}-linux-amd64.zip"
    fi

    wget ${SNELL_URL} -O snell-server.zip || {
        echo -e "${RED}下载 Snell 失败。${RESET}"
        exit 1
    }

    unzip -o snell-server.zip -d /usr/local/bin || {
        echo -e "${RED}解压缩 Snell 失败。${RESET}"
        exit 1
    }

    rm snell-server.zip
    chmod +x /usr/local/bin/snell-server
    RANDOM_PORT=$(shuf -i 30000-65000 -n 1)
    RANDOM_PSK=$(tr -dc A-Za-z0-9 </dev/urandom | head -c 20)

    if ! id "snell" &>/dev/null; then
        useradd -r -s /usr/sbin/nologin snell
    fi

    mkdir -p /etc/snell
    cat > /etc/snell/snell-server.conf << EOF
[snell-server]
listen = ::0:${RANDOM_PORT}
psk = ${RANDOM_PSK}
ipv6 = true
EOF

    cat > /etc/systemd/system/snell.service << EOF
[Unit]
Description=Snell Proxy Service
After=network.target

[Service]
Type=simple
User=snell
Group=snell
ExecStart=/usr/local/bin/snell-server -c /etc/snell/snell-server.conf
AmbientCapabilities=CAP_NET_BIND_SERVICE CAP_NET_ADMIN CAP_NET_RAW
CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_NET_ADMIN CAP_NET_RAW
LimitNOFILE=32768
Restart=on-failure
StandardOutput=journal
StandardError=journal
SyslogIdentifier=snell-server

[Install]
WantedBy=multi-user.target
EOF


    echo -e "${GREEN}Snell 安装成功${RESET}"
    systemctl daemon-reload && systemctl enable snell && systemctl start snell
    sleep 3 && journalctl -u snell.service -n 8 --no-pager
    HOST_IP=$(curl -s http://checkip.amazonaws.com)
    IP_COUNTRY=$(curl -s http://ipinfo.io/${HOST_IP}/country)
    echo -e "${GREEN}Snell 示例配置，项目地址: https://github.com/passeway/Snell${RESET}"
    cat << EOF > /etc/snell/config.txt
${IP_COUNTRY} = snell, ${HOST_IP}, ${RANDOM_PORT}, psk = ${RANDOM_PSK}, version = 5, reuse = true
EOF

    cat /etc/snell/config.txt
}

update_snell() {
    if [ ! -f "/usr/local/bin/snell-server" ]; then
        echo -e "${YELLOW}Snell 未安装，跳过更新${RESET}"
        return
    fi

    echo -e "${GREEN}Snell 正在更新${RESET}"
    systemctl stop snell
    wait_for_package_manager
    install_required_packages

    ARCH=$(arch)
    if [[ ${ARCH} == "aarch64" ]]; then
        SNELL_URL="https://dl.nssurge.com/snell/snell-server-${VERSION}-linux-aarch64.zip"
    else
        SNELL_URL="https://dl.nssurge.com/snell/snell-server-${VERSION}-linux-amd64.zip"
    fi

    wget ${SNELL_URL} -O snell-server.zip
    unzip -o snell-server.zip -d /usr/local/bin
    rm snell-server.zip
    chmod +x /usr/local/bin/snell-server
    systemctl restart snell
    echo -e "${GREEN}Snell 更新成功${RESET}"
    sleep 3 && journalctl -u snell.service -n 8 --no-pager
    echo -e "${GREEN}Snell 示例配置，项目地址: https://github.com/passeway/Snell${RESET}"
    cat /etc/snell/config.txt
}

uninstall_snell() {
    echo -e "${GREEN}正在卸载 Snell${RESET}"
    systemctl stop snell
    systemctl disable snell
    rm /etc/systemd/system/snell.service
    systemctl daemon-reload
    rm /usr/local/bin/snell-server
    rm -rf /etc/snell
    echo -e "${GREEN}Snell 卸载成功${RESET}"
}

show_menu() {
    clear
    check_snell_installed
    snell_installed=$?
    check_snell_running
    snell_running=$?

    if [ $snell_installed -eq 0 ]; then
        installation_status="${GREEN}已安装${RESET}"
        if version_output=$(/usr/local/bin/snell-server -version 2>&1); then
            snell_version=$(echo "$version_output" | grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+')
            if [ -n "$snell_version" ]; then
                version_status="${GREEN}${snell_version}${RESET}"
            else
                version_status="${RED}未知版本${RESET}"
            fi
        else
            version_status="${RED}未知版本${RESET}"
        fi

        if [ $snell_running -eq 0 ]; then
            running_status="${GREEN}已启动${RESET}"
        else
            running_status="${RED}未启动${RESET}"
        fi
    else
        installation_status="${RED}未安装${RESET}"
        running_status="${RED}未启动${RESET}"
        version_status="—"
    fi

    echo -e "${GREEN}=== Snell 管理工具 ===${RESET}"
    echo -e "安装状态: ${installation_status}"
    echo -e "运行状态: ${running_status}"
    echo -e "运行版本: ${version_status}"
    echo ""
    echo "1. 安装 Snell 服务"
    echo "2. 卸载 Snell 服务"
    if [ $snell_installed -eq 0 ]; then
        if [ $snell_running -eq 0 ]; then
            echo "3. 停止 Snell 服务"
        else
            echo "3. 启动 Snell 服务"
        fi
    fi
    echo "4. 更新 Snell 服务"
    echo "5. 重启 Snell 服务"
    echo "6. 查看 Snell 服务"
    echo "7. 查看 Snell 配置"
    echo "0. 退出"
    echo -e "${GREEN}======================${RESET}"
    read -p "请输入选项编号: " choice
    export choice
    echo ""
}

trap 'echo -e "${RED}已取消操作${RESET}"; exit' INT

main() {
    check_root

    while true; do
        show_menu
        case "${choice}" in
            1)
                install_snell
                ;;
            2)
                if [ $snell_installed -eq 0 ]; then
                    uninstall_snell
                else
                    echo -e "${RED}Snell 尚未安装${RESET}"
                fi
                ;;
            3)
                if [ $snell_installed -eq 0 ]; then
                    if [ $snell_running -eq 0 ]; then
                        stop_snell
                    else
                        start_snell
                    fi
                else
                    echo -e "${RED}Snell 尚未安装${RESET}"
                fi
                ;;
            4)
                update_snell
                ;;
            5)
                systemctl restart snell
                ;;
            6)
                systemctl status snell
                ;;
            7)
                if [ -f /etc/snell/config.txt ]; then
                    cat /etc/snell/config.txt
                else
                    echo -e "${RED}配置文件不存在${RESET}"
                fi
                ;;
            0)
                echo -e "${GREEN}已退出 Snell 管理工具${RESET}"
                exit 0
                ;;
            *)
                echo -e "${RED}无效的选项${RESET}"
                ;;
        esac
        read -p "按 enter 键继续..."
    done
}

main