#!/bin/bash

toolName=coturn
toolDeps="coturn miniupnpc"
toolConf="/etc/turnserver.conf"
toolServiceName="coturn.service"
publicIpRetry=20

# Get script working directory
# (when called from a different directory)
WDIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >>/dev/null 2>&1 && pwd)"
APTOPT=
CONFIG=0
SCRIPT_FILE=$(basename -- $0)
SCRIPT_NAME=${SCRIPT_FILE%%.*}
CONFIG_FILE_NAME="${SCRIPT_NAME}.cfg"
CONFIG_FILE_TEMPLATE="$WDIR/${CONFIG_FILE_NAME}.example"

seq_config() {
  #echo "Called once before executing steps."
  ## e.g. to source a config file manually:
  #. "$CONFIG_FILE"
  ## or to use sequencer api with global config file:
  #initSeqConfig "$CONFIG_FILE_NAME" "$CONFIG_FILE_TEMPLATE"
  ## or to use sequencer api with profile config file support:
  #initSeqConfig -p "$SCRIPT_NAME" "$CONFIG_FILE_TEMPLATE"
  #if [ $? -eq 0 ] ; then
  #  CONFIG=1
  #else
  #  # End if no configuration file exists
  #  dry || return -1
  #fi
  quiet && APTOPT="-y"
  return 0
}

step_1_info() { echo "Install $toolName"; }
step_1_alias() { echo "install"; }
step_1() {
  exe apt update
  exe apt install $toolDeps $APTOPT
}

step_10_info() {
  echo "Update $toolName 'external-ip' using dig [OPTION] [CUSTOM DNS]"
  echoinfo " [OPTION]"
  echoinfo "   -l  :  Always output update required and error information"
  echoinfo "          (even with -qq)"
}
step_10_alias() { echo "updateip"; }
step_10() {
  exitIfRunning
  shift
  local retryCount=$publicIpRetry
  local ipUpdater
  local ipRegex='^[0-2]*[0-9]{1,2}\.[0-2]*[0-9]{1,2}\.[0-2]*[0-9]{1,2}\.[0-2]*[0-9]{1,2}\/*[0-9]*$'
  local dnsUrl="46.182.19.48" #digitalcourage.de/support/zensurfreier-dns-server
  local dnsFallbackUrl="194.150.168.168" #dns.as250.net; Berlin/Frankfurt
  local lecho="info"
  if [ "$1" == "-l" ]; then
    lecho="echo"
    shift
  fi

  local pubIp

  while [ $retryCount -gt 0 ]; do
    pubIp=`"$(command -v upnpc)" -s | grep ^ExternalIPAddress | cut -c21-`
    [ $? -eq 0 ] && ipUpdater="upnpc" && break || "$lecho" "[$(date)] [W] Upnpc failed"
    pubIp=$(dig @$dnsUrl +short +timeout=1 cloud.imoff.de 2>>/dev/null)
    [ $? -eq 0 ] && ipUpdater="DNS" && break || "$lecho" "[$(date) [W] DNS lookup to $dnsUrl failed"
    pubIp=$(dig @$dnsFallbackUrl +short +timeout=1 cloud.imoff.de 2>>/dev/null)
    [ $? -eq 0 ] && ipUpdater="DNS Fallback" && break || "$lecho" "[$(date)] [W] DNS lookup to $dnsFallbackUrl failed"
    ((retryCount--))
  done

  if [[ ! $pubIp =~ $ipRegex ]]; then
    "$lecho" "[$(date)] [E] Couldn't aquire public IP. Giving up."
    return 1
  fi

  local confIp=`cat "$toolConf" | grep "^external-ip" | cut -d'=' -f2`

  if [ "$pubIp" != "$confIp" ]; then
    $lecho "[$(date)] [I] Update required (via $ipUpdater). New public ip: $pubIp"
    exe sed -i "s/^external-ip[[:space:]]*=.*/external-ip=${pubIp}/" "$toolConf"
    exe sleep 1
    $lecho "[$(date)] [I] Restarting $toolName"
    exe /bin/systemctl restart $toolServiceName
  else
    info "[$(date)] [I] No update required (via $ipUpdater). Current ip: $confIp"
  fi
}

step_12_info() { echo "Setup public ip update cron job every 5 minutes"; }
step_12_alias() { echo "cronip"; }
step_12() {
  info "Setup $ipCronLoc"
  addConf -s "$ipCron" "$ipCronLoc"
} 
ipCronLoc="/etc/cron.d/update_public_ip"
ipCron="*/5 * * * * root $WDIR/$SCRIPT_FILE -qq updateip"

step_100_info() { echo "Installation notes"; }
step_100_alias() { echo "notes"; }
step_100() {
  color green
  cat <<COTURN_EOF
# Port forwarding

3478 tcp/udp
5349 tcp/udp

# Permissions

When using letsencrypt certificates for transport security.

* Add user \`turnserver\` to group \`www-data\`

usermod -aG www-data turnserver

* In the renewal deploy script of cerbot add:

LOC_DOMAIN="yourdoma.in"
chown root:www-data /etc/letsencrypt/archive
chmod 750 /etc/letsencrypt/archive
chown root:www-data /etc/letsencrypt/archive/\$LOC_DOMAIN/privkey*
chmod g+r /etc/letsencrypt/archive/\$LOC_DOMAIN/privkey*

COTURN_EOF
}

readonly sqr_minVersion=16
. /usr/local/bin/sequencer.sh