#!/bin/bash

echo "Warning: This script is only tested on ubuntu 18.04 LTS"

DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"

# Require sudo privilege to setup and install packages

echo "Turning on BBR..."
sudo bash -c "modprobe tcp_bbr" &>/dev/null
sudo bash -c "echo tcp_bbr >> /etc/modules-load.d/modules.conf" &>/dev/null
sudo bash -c "echo net.core.default_qdisc=fq >> /etc/sysctl.conf" &>/dev/null
sudo bash -c "echo net.ipv4.tcp_congestion_control=bbr >> /etc/sysctl.conf" &>/dev/null
sudo sysctl -p  &>/dev/null

echo "Installing shadowsocks..."
sudo apt-get install -y shadowsocks-libev  &>/dev/null

echo "Creating random password, you can change later"
PASSWORD=$(head /dev/urandom | tr -dc A-Za-z0-9 | head -c 13 ; echo '')

cat > ss.config.json <<EOF
{
   "password" : "$PASSWORD",
   "timeout" : 1000,
   "server_port" : 8488,
   "method" : "chacha20-ietf-poly1305",
   "local_port" : 1080
}
EOF

echo "Adding shadowsocks to system service..."
sudo bash -c "cat > /etc/systemd/system/ss.service" <<EOF
[Unit]
Description=SS server
After=network.target

[Service]
User=$(whoami)
Restart=always
WorkingDirectory=$DIR
ExecStart=$(which ss-server) -c ss.config.json -u

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl enable ss

echo "Installation complete!"
echo "You can manage ss by 'sudo systemctl status/start/stop/restart ss'"