#!/usr/bin/env bash
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
export PATH
#=================================================================#
#   System Required:  CentOS, Debian, Ubuntu                      #
#   Description: One click Install Shadowsocks-go server          #
#   Author: Teddysun <i@teddysun.com>                             #
#   Thanks: @cyfdecyf <https://twitter.com/cyfdecyf>              #
#   Intro:  https://teddysun.com/392.html                         #
#==================================================================

clear
echo
echo "#############################################################"
echo "# One click Install Shadowsocks-go server                   #"
echo "# Intro: https://teddysun.com/392.html                      #"
echo "# Author: Teddysun <i@teddysun.com>                         #"
echo "# Github: https://github.com/shadowsocks/shadowsocks-go     #"
echo "#############################################################"
echo

# Make sure only root can run our script
rootness(){
    if [[ $EUID -ne 0 ]]; then
       echo "Error:This script must be run as root!" 1>&2
       exit 1
    fi
}

# Check OS
checkos(){
    if [ -f /etc/redhat-release ];then
        OS=CentOS
    elif [ ! -z "`cat /etc/issue | grep bian`" ];then
        OS=Debian
    elif [ ! -z "`cat /etc/issue | grep Ubuntu`" ];then
        OS=Ubuntu
    else
        echo "Not supported OS, Please reinstall OS and retry!"
        exit 1
    fi
}

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

# is 64bit or not
is_64bit(){
    if [ `getconf WORD_BIT` = '32' ] && [ `getconf LONG_BIT` = '64' ] ; then
        return 0
    else
        return 1
    fi
}

# 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
}

# Pre-installation settings
pre_install(){
    # Set shadowsocks-go config password
    echo "Please input password for shadowsocks-go:"
    read -p "(Default password: teddysun.com):" shadowsockspwd
    [ -z "$shadowsockspwd" ] && shadowsockspwd="teddysun.com"
    echo
    echo "---------------------------"
    echo "password = $shadowsockspwd"
    echo "---------------------------"
    echo
    # Set shadowsocks-go config port
    while true
    do
    echo -e "Please input port for shadowsocks-go [1-65535]:"
    read -p "(Default port: 8989):" shadowsocksport
    [ -z "${shadowsocksport}" ] && shadowsocksport="8989"
    expr ${shadowsocksport} + 0 &>/dev/null
    if [ $? -eq 0 ]; then
        if [ ${shadowsocksport} -ge 1 ] && [ ${shadowsocksport} -le 65535 ]; then
            echo
            echo "---------------------------"
            echo "port = $shadowsocksport"
            echo "---------------------------"
            echo
            break
        else
            echo "Input error! Please input correct numbers."
        fi
    else
        echo "Input error! Please input correct numbers."
    fi
    done
    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 $SAVEDSTTY
    }
    echo
    echo "Press any key to start...or Press Ctrl+C to cancel"
    char=`get_char`
    #Install necessary dependencies
    if [ "$OS" == 'CentOS' ];then
        yum install -y wget unzip gzip curl
    else
        apt-get -y update
        apt-get install -y wget unzip gzip curl
    fi
    # Get IP address
    echo "Getting Public IP address, Please wait a moment..."
    echo -e "Your main public IP is\t\033[32m $(get_ip) \033[0m"
    echo
    #Current folder
    cur_dir=`pwd`
}

# Download shadowsocks-go
download_files(){
    cd ${cur_dir}
    if is_64bit; then
        if ! wget -c http://dl.teddysun.com/shadowsocks/shadowsocks-server-linux64-1.1.5.gz;then
            echo "Failed to download shadowsocks-server-linux64-1.1.5.gz"
            exit 1
        fi
        gzip -d shadowsocks-server-linux64-1.1.5.gz
        if [ $? -eq 0 ];then
            echo "Decompress shadowsocks-server-linux64-1.1.5.gz success."
        else
            echo "Decompress shadowsocks-server-linux64-1.1.5.gz failed! Please check gzip command."
            exit 1
        fi
        mv -f shadowsocks-server-linux64-1.1.5 /usr/bin/shadowsocks-server
    else
        if ! wget -c http://dl.teddysun.com/shadowsocks/shadowsocks-server-linux32-1.1.5.gz;then
            echo "Failed to download shadowsocks-server-linux32-1.1.5.gz"
            exit 1
        fi
        gzip -d shadowsocks-server-linux32-1.1.5.gz
        if [ $? -eq 0 ];then
            echo "Decompress shadowsocks-server-linux32-1.1.5.gz success."
        else
            echo "Decompress shadowsocks-server-linux32-1.1.5.gz failed! Please check gzip command."
            exit 1
        fi
        mv -f shadowsocks-server-linux32-1.1.5 /usr/bin/shadowsocks-server
    fi

    # Download start script
    if [ "$OS" == 'CentOS' ];then
        if ! wget --no-check-certificate -O shadowsocks-go https://raw.githubusercontent.com/teddysun/shadowsocks_install/master/shadowsocks-go; then
            echo "Failed to download shadowsocks-go auto start script!"
            exit 1
        fi
    else
        if ! wget --no-check-certificate -O shadowsocks-go https://raw.githubusercontent.com/teddysun/shadowsocks_install/master/shadowsocks-go-debian; then
            echo "Failed to download shadowsocks-go auto start script!"
            exit 1
        fi
    fi
}

# Config shadowsocks
config_shadowsocks(){
    if [ ! -d /etc/shadowsocks ];then
        mkdir /etc/shadowsocks
    fi
    cat > /etc/shadowsocks/config.json<<-EOF
{
    "server":"0.0.0.0",
    "server_port":${shadowsocksport},
    "local_port":1080,
    "password":"${shadowsockspwd}",
    "method":"aes-256-cfb",
    "timeout":600
}
EOF
}

# firewall set
firewall_set(){
    echo "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 "port ${shadowsocksport} has been set up."
            fi
        else
            echo "WARNING: 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 [ $? -eq 0 ];then
            firewall-cmd --permanent --zone=public --add-port=${shadowsocksport}/tcp
            firewall-cmd --permanent --zone=public --add-port=${shadowsocksport}/udp
            firewall-cmd --reload
        else
            echo "Firewalld looks like not running, try to start..."
            systemctl start firewalld
            if [ $? -eq 0 ];then
                firewall-cmd --permanent --zone=public --add-port=${shadowsocksport}/tcp
                firewall-cmd --permanent --zone=public --add-port=${shadowsocksport}/udp
                firewall-cmd --reload
            else
                echo "WARNING: Try to start firewalld failed. please enable port ${shadowsocksport} manually if necessary."
            fi
        fi
    fi
    echo "firewall set completed..."
}

# Install 
install_go(){
    # Install shadowsocks-go
    if [ -s /usr/bin/shadowsocks-server ]; then
        echo "shadowsocks-go install success!"
        chmod +x /usr/bin/shadowsocks-server
        mv ${cur_dir}/shadowsocks-go /etc/init.d/shadowsocks
        chmod +x /etc/init.d/shadowsocks
        # Add run on system start up
        if [ "$OS" == 'CentOS' ]; then
            chkconfig --add shadowsocks
            chkconfig shadowsocks on
        else
            update-rc.d -f shadowsocks defaults
        fi
        # Start shadowsocks
        /etc/init.d/shadowsocks start
        if [ $? -eq 0 ]; then
            echo "Shadowsocks-go start success!"
        else
            echo "Shadowsocks-go start failure!"
        fi
    else
        echo
        echo "shadowsocks-go install failed!"
        exit 1
    fi
    cd $cur_dir
    clear
    echo
    echo "Congratulations, shadowsocks-go 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 Local Port: \033[41;37m 1080 \033[0m"
    echo -e "Your Encryption Method: \033[41;37m aes-256-cfb \033[0m"
    echo
    echo "Welcome to visit:https://teddysun.com/392.html"
    echo "Enjoy it!"
    echo
    exit 0
}

# Uninstall Shadowsocks-go
uninstall_shadowsocks_go(){
    printf "Are you sure uninstall shadowsocks-go? (y/n) "
    printf "\n"
    read -p "(Default: n):" answer
    if [ -z ${answer} ]; then
        answer="n"
    fi
    if [ "$answer" = "y" ]; then
        ps -ef | grep -v grep | grep -v ps | grep -i "shadowsocks-server" > /dev/null 2>&1
        if [ $? -eq 0 ]; then
            /etc/init.d/shadowsocks stop
        fi
        checkos
        if [ "$OS" == 'CentOS' ]; then
            chkconfig --del shadowsocks
        else
            update-rc.d -f shadowsocks remove
        fi
        # delete config file
        rm -rf /etc/shadowsocks
        # delete shadowsocks
        rm -f /etc/init.d/shadowsocks
        rm -f /usr/bin/shadowsocks-server
        echo "Shadowsocks-go uninstall success!"
    else
        echo "Uninstall cancelled, Nothing to do"
    fi
}

# Install Shadowsocks-go
install_shadowsocks_go(){
    checkos
    rootness
    disable_selinux
    pre_install
    download_files
    config_shadowsocks
    if [ "$OS" == 'CentOS' ]; then
        firewall_set
    fi
    install_go
}

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