#!/usr/bin/env bash
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
export PATH
#===================================================================#
#   System Required:  CentOS 6 or 7                                 #
#   Description: Install Shadowsocks-libev server for CentOS 6 or 7 #
#   Author: Teddysun <i@teddysun.com>                               #
#   Thanks: @madeye <https://github.com/madeye>                     #
#   Intro:  https://teddysun.com/357.html                           #
#===================================================================#

# Current folder
cur_dir=$(pwd)

libsodium_file='libsodium-1.0.18'
libsodium_url='https://github.com/jedisct1/libsodium/releases/download/1.0.18-RELEASE/libsodium-1.0.18.tar.gz'

mbedtls_file='mbedtls-2.16.12'
mbedtls_url='https://github.com/Mbed-TLS/mbedtls/archive/refs/tags/v2.16.12.tar.gz'

# Stream Ciphers
ciphers=(
aes-256-gcm
aes-192-gcm
aes-128-gcm
aes-256-ctr
aes-192-ctr
aes-128-ctr
aes-256-cfb
aes-192-cfb
aes-128-cfb
camellia-128-cfb
camellia-192-cfb
camellia-256-cfb
xchacha20-ietf-poly1305
chacha20-ietf-poly1305
chacha20-ietf
chacha20
salsa20
rc4-md5
)
# Color
red='\033[0;31m'
green='\033[0;32m'
yellow='\033[0;33m'
plain='\033[0m'

# Make sure only root can run our script
[[ $EUID -ne 0 ]] && echo -e "[${red}Error${plain}] This script must be run as root!" && exit 1

# Disable selinux
disable_selinux(){
    if [ -s /etc/selinux/config ] && grep 'SELINUX=enforcing' /etc/selinux/config; then
        sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
        setenforce 0
    fi
}

get_ip(){
    local IP=$( ip addr | egrep -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | egrep -v "^192\.168|^172\.1[6-9]\.|^172\.2[0-9]\.|^172\.3[0-2]\.|^10\.|^127\.|^255\.|^0\." | head -n 1 )
    [ -z "${IP}" ] && IP=$( wget -qO- -t1 -T2 ipv4.icanhazip.com )
    [ -z "${IP}" ] && IP=$( wget -qO- -t1 -T2 ipinfo.io/ip )
    [ ! -z "${IP}" ] && echo "${IP}" || echo
}

get_ipv6(){
    local ipv6=$(wget -qO- -t1 -T2 ipv6.icanhazip.com)
    if [ -z "${ipv6}" ]; then
        return 1
    else
        return 0
    fi
}

get_char(){
    SAVEDSTTY=$(stty -g)
    stty -echo
    stty cbreak
    dd if=/dev/tty bs=1 count=1 2> /dev/null
    stty -raw
    stty echo
    stty "$SAVEDSTTY"
}

get_latest_version(){
    ver=$(wget --no-check-certificate -qO- https://api.github.com/repos/shadowsocks/shadowsocks-libev/releases/latest | grep 'tag_name' | cut -d\" -f4)
    [ -z "${ver}" ] && echo "Error: Get shadowsocks-libev latest version failed" && exit 1
    shadowsocks_libev_ver="shadowsocks-libev-$(echo "${ver}" | sed -e 's/^[a-zA-Z]//g')"
    download_link="https://github.com/shadowsocks/shadowsocks-libev/releases/download/${ver}/${shadowsocks_libev_ver}.tar.gz"
    init_script_link="https://raw.githubusercontent.com/teddysun/shadowsocks_install/master/shadowsocks-libev"
}

check_installed(){
    if [ "$(command -v "$1")" ]; then
        return 0
    else
        return 1
    fi
}

check_version(){
    check_installed "ss-server"
    if [ $? -eq 0 ]; then
        installed_ver=$(ss-server -h | grep shadowsocks-libev | cut -d' ' -f2)
        get_latest_version
        latest_ver=$(echo "${ver}" | sed -e 's/^[a-zA-Z]//g')
        if [ "${latest_ver}" == "${installed_ver}" ]; then
            return 0
        else
            return 1
        fi
    else
        return 2
    fi
}

print_info(){
    clear
    echo "#############################################################"
    echo "# Install Shadowsocks-libev server for CentOS 6 or 7        #"
    echo "# Intro:  https://teddysun.com/357.html                     #"
    echo "# Author: Teddysun <i@teddysun.com>                         #"
    echo "# Github: https://github.com/shadowsocks/shadowsocks-libev  #"
    echo "#############################################################"
    echo
}

# Check system
check_sys(){
    local checkType=$1
    local value=$2

    local release=''
    local systemPackage=''

    if [[ -f /etc/redhat-release ]]; then
        release="centos"
        systemPackage="yum"
    elif grep -Eqi "debian|raspbian" /etc/issue; then
        release="debian"
        systemPackage="apt"
    elif grep -Eqi "ubuntu" /etc/issue; then
        release="ubuntu"
        systemPackage="apt"
    elif grep -Eqi "centos|red hat|redhat" /etc/issue; then
        release="centos"
        systemPackage="yum"
    elif grep -Eqi "debian|raspbian" /proc/version; then
        release="debian"
        systemPackage="apt"
    elif grep -Eqi "ubuntu" /proc/version; then
        release="ubuntu"
        systemPackage="apt"
    elif grep -Eqi "centos|red hat|redhat" /proc/version; then
        release="centos"
        systemPackage="yum"
    fi

    if [[ "${checkType}" == "sysRelease" ]]; then
        if [ "${value}" == "${release}" ]; then
            return 0
        else
            return 1
        fi
    elif [[ "${checkType}" == "packageManager" ]]; then
        if [ "${value}" == "${systemPackage}" ]; then
            return 0
        else
            return 1
        fi
    fi
}

version_gt(){
    test "$(echo "$@" | tr " " "\n" | sort -V | head -n 1)" != "$1"
}

check_kernel_version(){
    local kernel_version=$(uname -r | cut -d- -f1)
    if version_gt "${kernel_version}" 3.7.0; then
        return 0
    else
        return 1
    fi
}

check_kernel_headers(){
    if check_sys packageManager yum; then
        if rpm -qa | grep -q headers-$(uname -r); then
            return 0
        else
            return 1
        fi
    elif check_sys packageManager apt; then
        if dpkg -s linux-headers-$(uname -r) > /dev/null 2>&1; then
            return 0
        else
            return 1
        fi
    fi
    return 1
}

# Get version
getversion(){
    if [[ -s /etc/redhat-release ]]; then
        grep -oE  "[0-9.]+" /etc/redhat-release
    else
        grep -oE  "[0-9.]+" /etc/issue
    fi
}

# CentOS version
centosversion(){
    if check_sys sysRelease centos; then
        local code=$1
        local version="$(getversion)"
        local main_ver=${version%%.*}
        if [ "$main_ver" == "$code" ]; then
            return 0
        else
            return 1
        fi
    else
        return 1
    fi
}

# Pre-installation settings
pre_install(){
    # Check OS system
    if check_sys sysRelease centos; then
        # Not support CentOS 5
        if centosversion 5; then
            echo -e "[${red}Error${plain}] Not support CentOS 5, please change to CentOS 6 or 7 and try again."
            exit 1
        fi
    else
        echo -e "[${red}Error${plain}] Your OS is not supported to run it, please change OS to CentOS and try again."
        exit 1
    fi

    # Check version
    check_version
    status=$?
    if [ ${status} -eq 0 ]; then
        echo -e "[${green}Info${plain}] Latest version ${green}${shadowsocks_libev_ver}${plain} has already been installed, nothing to do..."
        exit 0
    elif [ ${status} -eq 1 ]; then
        echo -e "Installed version: ${red}${installed_ver}${plain}"
        echo -e "Latest version: ${red}${latest_ver}${plain}"
        echo -e "[${green}Info${plain}] Upgrade shadowsocks libev to latest version..."
        ps -ef | grep -v grep | grep -i "ss-server" > /dev/null 2>&1
        if [ $? -eq 0 ]; then
            /etc/init.d/shadowsocks stop
        fi
    elif [ ${status} -eq 2 ]; then
        print_info
        get_latest_version
        echo -e "[${green}Info${plain}] Latest version: ${green}${shadowsocks_libev_ver}${plain}"
        echo
    fi

    # Set shadowsocks-libev config password
    echo "Please enter password for shadowsocks-libev:"
    read -p "(Default password: teddysun.com):" shadowsockspwd
    [ -z "${shadowsockspwd}" ] && shadowsockspwd="teddysun.com"
    echo
    echo "---------------------------"
    echo "password = ${shadowsockspwd}"
    echo "---------------------------"
    echo

    # Set shadowsocks-libev config port
    while true
    do
    dport=$(shuf -i 9000-19999 -n 1)
    echo -e "Please enter a port for shadowsocks-libev [1-65535]"
    read -p "(Default port: ${dport}):" shadowsocksport
    [ -z "$shadowsocksport" ] && shadowsocksport=${dport}
    expr "${shadowsocksport}" + 1 &>/dev/null
    if [ $? -eq 0 ]; then
        if [ "${shadowsocksport}" -ge 1 ] && [ "${shadowsocksport}" -le 65535 ] && [ "${shadowsocksport:0:1}" != 0 ]; then
            echo
            echo "---------------------------"
            echo "port = ${shadowsocksport}"
            echo "---------------------------"
            echo
            break
        fi
    fi
    echo -e "[${red}Error${plain}] Please enter a correct number [1-65535]"
    done

    # Set shadowsocks config stream ciphers
    while true
    do
    echo -e "Please select stream cipher for shadowsocks-libev:"
    for ((i=1;i<=${#ciphers[@]};i++ )); do
        hint="${ciphers[$i-1]}"
        echo -e "${green}${i}${plain}) ${hint}"
    done
    read -p "Which cipher you'd select(Default: ${ciphers[0]}):" pick
    [ -z "$pick" ] && pick=1
    expr ${pick} + 1 &>/dev/null
    if [ $? -ne 0 ]; then
        echo -e "[${red}Error${plain}] Please enter a number"
        continue
    fi
    if [[ "$pick" -lt 1 || "$pick" -gt ${#ciphers[@]} ]]; then
        echo -e "[${red}Error${plain}] Please enter a number between 1 and ${#ciphers[@]}"
        continue
    fi
    shadowsockscipher=${ciphers[$pick-1]}
    echo
    echo "---------------------------"
    echo "cipher = ${shadowsockscipher}"
    echo "---------------------------"
    echo
    break
    done

    echo
    echo "Press any key to start...or press Ctrl+C to cancel"
    char=$(get_char)
    #Install necessary dependencies
    echo -e "[${green}Info${plain}] Checking the EPEL repository..."
    if [ ! -f /etc/yum.repos.d/epel.repo ]; then
        yum install -y -q epel-release
    fi
    [ ! -f /etc/yum.repos.d/epel.repo ] && echo -e "[${red}Error${plain}] Install EPEL repository failed, please check it." && exit 1
    [ ! "$(command -v yum-config-manager)" ] && yum install -y -q yum-utils
    if [ x"$(yum-config-manager epel | grep -w enabled | awk '{print $3}')" != x"True" ]; then
        yum-config-manager --enable epel
    fi
    echo -e "[${green}Info${plain}] Checking the EPEL repository complete..."
    yum install -y -q unzip openssl openssl-devel gettext gcc autoconf libtool automake make asciidoc xmlto libev-devel pcre pcre-devel git c-ares-devel
}

download() {
    local filename=${1}
    local cur_dir=$(pwd)
    if [ -s "${filename}" ]; then
        echo -e "[${green}Info${plain}] ${filename} [found]"
    else
        echo -e "[${green}Info${plain}] ${filename} not found, download now..."
        wget --no-check-certificate -cq -t3 -T60 -O "${1}" "${2}"
        if [ $? -eq 0 ]; then
            echo -e "[${green}Info${plain}] ${filename} download completed..."
        else
            echo -e "[${red}Error${plain}] Failed to download ${filename}, please download it to ${cur_dir} directory manually and try again."
            exit 1
        fi
    fi
}

# Download latest shadowsocks-libev
download_files(){
    cd "${cur_dir}" || exit

    download "${shadowsocks_libev_ver}.tar.gz" "${download_link}"
    download "${libsodium_file}.tar.gz" "${libsodium_url}"
    download "${mbedtls_file}.tar.gz" "${mbedtls_url}"
    download "/etc/init.d/shadowsocks" "${init_script_link}"
}

install_libsodium() {
    if [ ! -f /usr/lib/libsodium.a ]; then
        cd "${cur_dir}" || exit
        tar zxf ${libsodium_file}.tar.gz
        cd ${libsodium_file} || exit
        ./configure --prefix=/usr && make && make install
        if [ $? -ne 0 ]; then
            echo -e "[${red}Error${plain}] ${libsodium_file} install failed."
            exit 1
        fi
    else
        echo -e "[${green}Info${plain}] ${libsodium_file} already installed."
    fi
}

install_mbedtls() {
    if [ ! -f /usr/lib/libmbedtls.a ]; then
        cd "${cur_dir}" || exit
        tar zxf "${mbedtls_file}.tar.gz"
        cd "${mbedtls_file}" || exit
        make SHARED=1 CFLAGS=-fPIC
        make DESTDIR=/usr install
        if [ $? -ne 0 ]; then
            echo -e "[${red}Error${plain}] ${mbedtls_file} install failed."
            exit 1
        fi
    else
        echo -e "[${green}Info${plain}] ${mbedtls_file} already installed."
    fi
}

# Config shadowsocks
config_shadowsocks(){
    local server_value="\"0.0.0.0\""
    if get_ipv6; then
        server_value="[\"[::0]\",\"0.0.0.0\"]"
    fi

    if [ ! -d /etc/shadowsocks-libev ]; then
        mkdir -p /etc/shadowsocks-libev
    fi
    cat > /etc/shadowsocks-libev/config.json<<-EOF
{
    "server":${server_value},
    "server_port":${shadowsocksport},
    "password":"${shadowsockspwd}",
    "timeout":300,
    "user":"nobody",
    "method":"${shadowsockscipher}",
    "fast_open":false,
    "nameserver":"1.0.0.1",
    "mode":"tcp_and_udp"
}
EOF
}

# Firewall set
firewall_set(){
    echo -e "[${green}Info${plain}] firewall set start..."
    if centosversion 6; then
        /etc/init.d/iptables status > /dev/null 2>&1
        if [ $? -eq 0 ]; then
            iptables -L -n | grep -i "${shadowsocksport}" > /dev/null 2>&1
            if [ $? -ne 0 ]; then
                iptables -I INPUT -m state --state NEW -m tcp -p tcp --dport "${shadowsocksport}" -j ACCEPT
                iptables -I INPUT -m state --state NEW -m udp -p udp --dport "${shadowsocksport}" -j ACCEPT
                /etc/init.d/iptables save
                /etc/init.d/iptables restart
            else
                echo -e "[${green}Info${plain}] port ${shadowsocksport} has been set up."
            fi
        else
            echo -e "[${yellow}Warning${plain}] iptables looks like shutdown or not installed, please manually set it if necessary."
        fi
    elif centosversion 7; then
        systemctl status firewalld > /dev/null 2>&1
        if [ $? -eq 0 ]; then
            default_zone=$(firewall-cmd --get-default-zone)
            firewall-cmd --permanent --zone="${default_zone}" --add-port="${shadowsocksport}"/tcp
            firewall-cmd --permanent --zone="${default_zone}" --add-port="${shadowsocksport}"/udp
            firewall-cmd --reload
        else
            echo -e "[${yellow}Warning${plain}] firewalld looks like not running or not installed, please enable port ${shadowsocksport} manually if necessary."
        fi
    fi
    echo -e "[${green}Info${plain}] firewall set completed..."
}

# Install Shadowsocks-libev
install_shadowsocks(){
    install_libsodium
    install_mbedtls

    ldconfig
    cd "${cur_dir}" || exit
    tar zxf "${shadowsocks_libev_ver}".tar.gz
    cd "${shadowsocks_libev_ver}" || exit
    ./configure --disable-documentation
    make && make install
    if [ $? -eq 0 ]; then
        chmod +x /etc/init.d/shadowsocks
        chkconfig --add shadowsocks
        chkconfig shadowsocks on
        # Start shadowsocks
        /etc/init.d/shadowsocks start
        if [ $? -eq 0 ]; then
            echo -e "[${green}Info${plain}] Shadowsocks-libev start success!"
        else
            echo -e "[${yellow}Warning${plain}] Shadowsocks-libev start failure!"
        fi
    else
        echo
        echo -e "[${red}Error${plain}] Shadowsocks-libev install failed. please visit https://teddysun.com/357.html and contact."
        exit 1
    fi

    cd "${cur_dir}" || exit
    rm -rf "${shadowsocks_libev_ver}" "${shadowsocks_libev_ver}".tar.gz
    rm -rf ${libsodium_file} ${libsodium_file}.tar.gz
    rm -rf "${mbedtls_file}" "${mbedtls_file}"-apache.tgz

    clear
    echo
    echo -e "Congratulations, Shadowsocks-libev server install completed!"
    echo -e "Your Server IP        : \033[41;37m $(get_ip) \033[0m"
    echo -e "Your Server Port      : \033[41;37m ${shadowsocksport} \033[0m"
    echo -e "Your Password         : \033[41;37m ${shadowsockspwd} \033[0m"
    echo -e "Your Encryption Method: \033[41;37m ${shadowsockscipher} \033[0m"
    echo
    echo "Welcome to visit:https://teddysun.com/357.html"
    echo "Enjoy it!"
    echo
}

# Install Shadowsocks-libev
install_shadowsocks_libev(){
    disable_selinux
    pre_install
    download_files
    config_shadowsocks
    firewall_set
    install_shadowsocks
}

# Uninstall Shadowsocks-libev
uninstall_shadowsocks_libev(){
    clear
    print_info
    printf "Are you sure uninstall Shadowsocks-libev? (y/n)"
    printf "\n"
    read -p "(Default: n):" answer
    [ -z "${answer}" ] && answer="n"

    if [ "${answer}" == "y" ] || [ "${answer}" == "Y" ]; then
        ps -ef | grep -v grep | grep -i "ss-server" > /dev/null 2>&1
        if [ $? -eq 0 ]; then
            /etc/init.d/shadowsocks stop
        fi
        chkconfig --del shadowsocks
        rm -fr /etc/shadowsocks-libev
        rm -f /usr/local/bin/ss-local
        rm -f /usr/local/bin/ss-tunnel
        rm -f /usr/local/bin/ss-server
        rm -f /usr/local/bin/ss-manager
        rm -f /usr/local/bin/ss-redir
        rm -f /usr/local/bin/ss-nat
        rm -f /usr/local/lib/libshadowsocks-libev.a
        rm -f /usr/local/lib/libshadowsocks-libev.la
        rm -f /usr/local/include/shadowsocks.h
        rm -f /usr/local/lib/pkgconfig/shadowsocks-libev.pc
        rm -f /usr/local/share/man/man1/ss-local.1
        rm -f /usr/local/share/man/man1/ss-tunnel.1
        rm -f /usr/local/share/man/man1/ss-server.1
        rm -f /usr/local/share/man/man1/ss-manager.1
        rm -f /usr/local/share/man/man1/ss-redir.1
        rm -f /usr/local/share/man/man1/ss-nat.1
        rm -f /usr/local/share/man/man8/shadowsocks-libev.8
        rm -fr /usr/local/share/doc/shadowsocks-libev
        rm -f /etc/init.d/shadowsocks
        echo "Shadowsocks-libev uninstall success!"
    else
        echo
        echo "uninstall cancelled, nothing to do..."
        echo
    fi
}

# Initialization step
action=$1
[ -z "$1" ] && action=install
case "$action" in
    install|uninstall)
        ${action}_shadowsocks_libev
        ;;
    *)
        echo "Arguments error! [${action}]"
        echo "Usage: $(basename "$0") [install|uninstall]"
        ;;
esac