#!/usr/bin/env bash
# Copyright (C) 2020 Private Internet Access, Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# This function allows you to check if the required tools have been installed.
check_tool() {
  cmd=$1
  if ! command -v "$cmd" >/dev/null; then
    echo "$cmd could not be found"
    echo "Please install $cmd"
    exit 1
  fi
}

# Now we call the function to make sure we can use curl and jq.
check_tool curl
check_tool jq

# This function creates a timestamp, to use for setting $TOKEN_EXPIRATION
timeout_timestamp() {
  date +"%c" --date='1 day' # Timestamp 24 hours
}

# Check if terminal allows output, if yes, define colors for output
if [[ -t 1 ]]; then
  ncolors=$(tput colors)
  if [[ -n $ncolors && $ncolors -ge 8 ]]; then
    red=$(tput setaf 1) # ANSI red
    green=$(tput setaf 2) # ANSI green
    nc=$(tput sgr0) # No Color
  else
    red=''
    green=''
    nc='' # No Color
  fi
fi

# Only allow script to run as root
if (( EUID != 0 )); then
  echo -e "${red}This script needs to be run as root. Try again with 'sudo $0'${nc}"
  exit 1
fi

mkdir -p /opt/piavpn-manual

if [[ -z $PIA_USER || -z $PIA_PASS ]]; then
  echo "If you want this script to automatically get a token from the Meta"
  echo "service, please add the variables PIA_USER and PIA_PASS. Example:"
  echo "$ PIA_USER=p0123456 PIA_PASS=xxx ./get_token.sh"
  exit 1
fi

echo -n "Checking login credentials..."

generateTokenResponse=$(curl -s --location --request POST \
  'https://www.privateinternetaccess.com/api/client/v2/token' \
  --form "username=$PIA_USER" \
  --form "password=$PIA_PASS" )

if [ "$(echo "$generateTokenResponse" | jq -r '.token')" == "" ]; then
  echo
  echo
  echo -e "${red}Could not authenticate with the login credentials provided!${nc}"
  echo
  exit
fi

echo -e "${green}OK!"
echo
token=$(echo "$generateTokenResponse" | jq -r '.token')
tokenExpiration=$(timeout_timestamp)
tokenLocation=/opt/piavpn-manual/token
echo -e "PIA_TOKEN=$token${nc}"
echo "$token" > "$tokenLocation" || exit 1
echo "$tokenExpiration" >> "$tokenLocation"
echo
echo "This token will expire in 24 hours, on $tokenExpiration."
echo