#!/bin/bash

seqDir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >>/dev/null 2>&1 && pwd )"
toolName="snmpd"
toolConfigLoc="/etc/snmp"
toolConfig="${toolConfigLoc}/snmpd.conf"


step_1_info() { echo "Install packages for $toolName"; }
step_1_alias() { ALIAS="install"; }
step_1() {
  exe apt update
  if [ $QUIET != 0 ]; then
    exe apt-get -qq install $toolName
  else
    exe apt install $toolName
  fi
  endReturn -o $? "$toolName installation failed"
}

step_2_info() { echo "Setup snmp v3 access"; }
step_2() {
  #
  ## Create authentication entry
  exep "cat \"$v3AuthLoc\" | grep -e '^\s*usmUser'"
  if [ "$?" == "0" ]; then
    echo

    exe read -p "User entry found. Continue: y/n(default)? " answer
    case $answer in
      [yY])
        echo
        echo Continuing installation...
        ;;
      *)
        echo
        echo Installation aborted
        return 1; 
        ;;
    esac 
  fi

  read -p "SNMPv3 Username: " v3User
  read -s -p "SNMPv3 Password: " v3Pass
  echo

  exe service snmpd stop

  # this line will be replaced on start of snmpd with a line starting with:
  # usmUser
  v3AuthEntry="createUser ${v3User} SHA \"${v3Pass}\" DES" 
  addConf -a "$v3AuthEntry" "$v3AuthLoc"

  #
  ## Add custom base configuration
  addConf -c "" "${toolConfig}"
  exe cp "${seqDir}/snmpd.conf" "${toolConfig}"

  #
  ## Add username as rouser
  exe sed -i "s/authOnlyUser/${v3User}/" "$toolConfig"

  #
  ## Write syslocation
  exe read -p "sysLocation: " v3Location
  exe read -p "sysContact (name <webmaster@example.com>): " v3Contact

  exe sed -i "s/\(sysLocation\s*\).*/\1${v3Location}/" "$toolConfig"
  exe sed -i "s/\(sysContact\s*\).*/\1${v3Contact}/" "$toolConfig"

  exe service snmpd start
}
v3AuthLoc="/var/lib/snmp/snmpd.conf"

step_20_info() { echo "Extend $toolName for Raspberry Pi"; }
step_20_alias() { ALIAS="raspberry"; }
step_20() {
  checkExtend raspberry
  if [ "$?" != "0" ]; then
    return 1
  fi

  exe wget https://raw.githubusercontent.com/librenms/librenms-agent/master/snmp/raspberry.sh -O "${rpiExtendLoc}"
  endReturn -o $? "Download failed"
  exe chmod +x "$rpiExtendLoc"

  addConf -a "extend raspberry /etc/snmp/raspberry.sh" "$toolConfig"
  addConf -c "$rpiSudoersContent" "$rpiSudoersLoc"

  exe service snmpd restart
}

rpiExtendLoc="${toolConfigLoc}/raspberry.sh"
rpiSudoersLoc="/etc/sudoers.d/snmprpi"
rpiSudoersContent="
Debian-snmp ALL=(ALL) NOPASSWD: /etc/snmp/raspberry.sh, /usr/bin/vcgencmd*"

step_22_info() { echo "Extend $toolName with OS update availablity"; }
step_22_alias() { ALIAS="osupdate"; }
step_22() {
  checkExtend osupdate 
  if [ "$?" != "0" ]; then
    return 1
  fi
  
  exe wget https://raw.githubusercontent.com/librenms/librenms-agent/master/snmp/osupdate -O "${osUpdateExtendLoc}"
  endReturn -o $? "Download failed"
  exe chmod +x "$osUpdateExtendLoc"
  addConf -a "extend osupdate $osUpdateExtendLoc" "$toolConfig"

  exe service snmpd restart
}
osUpdateExtendLoc="${toolConfigLoc}/osupdate"

step_23_info() { echo "Create cron job for periodical (every 8 hours) apt-get update"; }
step_23() {
  addConf -s "$osUpdateCronContent" "$osUpdateCron"
}
osUpdateCron="/etc/cron.d/aptUpdate"
osUpdateCronContent="22 */6 * * * root /usr/bin/apt-get -qq update"

#fail2ban
#exe wget https://github.com/librenms/librenms-agent/raw/master/snmp/fail2ban -O "${toolConfig}/fail2ban"
# nginx
#exe wget https://raw.githubusercontent.com/librenms/librenms-agent/master/snmp/nginx -O "${toolConfig}/nginx"
# php-fpm
#exe wget https://github.com/librenms/librenms-agent/raw/master/snmp/phpfpmsp -O "${toolConfig}/phpfpmsp"

checkExtend() {
  exep "cat \"$toolConfig\" | grep -e '^\s*extend\s\+${1}' >>/dev/null 2>&1"
  # Only warn if entry exists and dry-run is not seleted
  if [ "$?" == "0" ] && [ "$DRY" == "0" ] ; then  
    echo "[WARN] Extend for ${1} exists"
    return 1
  fi 

  # adding dry run output for clarification
  if [ "$DRY" != "0" ] ; then
    echo "-- check if \"extend ${1}\" exists..dry-run"
  fi

  return 0
}

VERSION_SEQREV=7
. sequencer.sh