#!/usr/bin/env bash

# DESCRIPTION:
#   print length of all zimbra queues
#   or
#   letsencrypt update certificate procedure
#
# DEPENDENCIES:
#   - privileged rights
#   - zimbra zmcontrol, zmqstat, zmcertmgr
#   - curl
#   - openssl
#   - cerbot
#   - Python 3
#   - existing /usr/local/bin/sendmail.py
#
# PARAMETERS:
#   1: "qn" - execution without pauses
#   2: "que" - print length of all zimbra queues
#   2: "svc" - print number of stopped services
#   2: "ssl" - letsencrypt certificate update procedure
#   3: custom configuration file path
#
# FUNCTIONS:
#

#######################################
# Print message and add to log.
# Globals:
#   logs
# Arguments:
#   1: message to print and logging
#######################################
addtologs() {
  echo "$(date +'%Y.%m.%d-%H:%M:%S') $1" | tee -a "${logs}"
}

#######################################
# Waiting for press [ENTER].
# Globals:
#   None
# Arguments:
#   None
#######################################
execpause() {
  read -r -p "Press [ENTER] to continue... "
}

#######################################
# Exit procedure.
# Globals:
#   show
# Arguments:
#   None
#######################################
execquite() {
  addtologs "execution time is $(($(date +%s)-time)) seconds, exit"
  if [ "${show}" != "qn" ]; then
    execpause
  fi
  exit
}

#######################################
# Error exit procedure
# Globals:
#   None
# Arguments:
#   1: message to print and logging
#######################################
execerror() {
  addtologs "error: $1"
  execquite
}

#######################################
# Parsing config file and creating global vars.
# Globals:
#   None
# Arguments:
#   None
#######################################
getconfig() {
  logs=$(grep "logs=" "${conf}" | cut -d= -f2)
  python3=$(grep "python3=" "${conf}" | cut -d= -f2)
  certemail=$(grep "certemail=" "${conf}" | cut -d= -f2)
  certfirst=$(grep "certfirst=" "${conf}" | cut -d= -f2)
  IFS=" " read -r -a certalias <<< "$(grep "certalias=" "${conf}" | cut -d= -f2)"

}

#######################################
# Checking user rights.
# Globals:
#   None
# Arguments:
#   None
# return:
#   0 - if privileged rights, 1 - if not privileged rights
#######################################
checkroot() {
  if [ "${EUID}" -ne 0 ]; then
    return 1 # false
  else
    return 0 # true
  fi
}

#######################################
# Counting zimbra queues.
# Globals:
#   None
# Arguments:
#   None
# return:
#   length of all queues
#######################################
calcqueue(){
  object=0
  while read -r QUE; do
    object=$(( object + $(echo "${QUE}" | cut -d= -f2) ))
  done <<< "$(/opt/zimbra/libexec/zmqstat)"
  printf "%s\n" "${object}"
  return "${object}"
}

#######################################
# Counting zimbra stopped services.
# Globals:
#   None
# Arguments:
#   None
# return:
#   number of stopped services
#######################################
isrunning(){
  counter=0
  while read -r service; do
    if ! grep -q "$(cat /etc/hostname)" <<< "${service}"; then
      if grep -q "Stopped" <<< "${service}"; then
        (( counter++ ))
      fi
    fi
  done <<< "$(su - zimbra -c '/opt/zimbra/bin/zmcontrol status')"
  printf "%s\n" "${counter}"
  return "${counter}"
}

#######################################
# Print certificate expiration date in epoch
# Globals:
#   None
# Arguments:
#   1: certificate path or site url
#######################################
certcheck() {
  if [ -e "${1}" ]; then
    printf '%s\n' "$(date -d "$(openssl x509 -text -noout -in "${1}" | grep 'Not After' | cut -d':' -f2-)" +%s)"
  else
    export LANG=C
    printf '%s\n' "$(date -d "$(curl --insecure -vvI "${1}" 2>&1 | grep "expire date" | cut -d':' -f2-)" +%s)"
  fi
}

#######################################
# Renew and deploy certificate
# Globals:
#   certfirst
#   certalias
#   certemail
# Arguments:
#   None
#######################################
certrenew() {
  # letsencrypt request
  su - zimbra -c "/opt/zimbra/bin/zmcontrol stop"
  certarray="-d ${certfirst}"
  if [ ${#certalias[@]} -ne 0 ]; then
    for domain in "${certalias[@]}"; do
      certarray+=" -d ${domain}"
    done
  fi
  certbot certonly --standalone --email "${certemail}" --preferred-chain "ISRG Root X1" "${certarray}"
  wget -O - https://letsencrypt.org/certs/isrgrootx1.pem.txt --no-check-certificate >> "/etc/letsencrypt/live/${certfirst}/chain.pem"
  su - zimbra -c "/opt/zimbra/bin/zmcontrol start"

  # zimbra cert deploy
  cp "/etc/letsencrypt/live/${certfirst}/privkey.pem" /opt/zimbra/ssl/zimbra/commercial/commercial.key
  cp "/etc/letsencrypt/live/${certfirst}/chain.pem" /opt/zimbra/ssl/zimbra/commercial/chain.pem
  cp "/etc/letsencrypt/live/${certfirst}/cert.pem" /opt/zimbra/ssl/zimbra/commercial/cert.pem
  chown -R zimbra:zimbra /opt/zimbra/ssl/zimbra/commercial/
  su - zimbra -c "/opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key /opt/zimbra/ssl/zimbra/commercial/cert.pem /opt/zimbra/ssl/zimbra/commercial/chain.pem"
  su - zimbra -c "/opt/zimbra/bin/zmcertmgr deploycrt comm /opt/zimbra/ssl/zimbra/commercial/cert.pem /opt/zimbra/ssl/zimbra/commercial/chain.pem"
  su - zimbra -c "/opt/zimbra/bin/zmcontrol restart"
}

#######################################
# Send email information about deployed certificate
# Globals:
#   python3
#   certfirst
# Arguments:
#   None
#######################################
startsendmail() {
  subj="[SSL Status] $(cat /etc/hostname): certificates renewed"
  (
    "${python3}" /usr/local/bin/sendmail.py \
    -u "$(grep "from=" /usr/local/bin/sendmail.config | cut -d= -f2)" \
    -p "$(grep "pass=" /usr/local/bin/sendmail.config | cut -d= -f2)" \
    -d "$(grep "dest=" /usr/local/bin/sendmail.config | cut -d= -f2)" \
    --smtp "$(grep "smtp=" /usr/local/bin/sendmail.config | cut -d= -f2)" \
    --port "$(grep "port=" /usr/local/bin/sendmail.config | cut -d= -f2)" \
    --stls "True" \
    --subj "${subj}" \
    --text "$(curl --insecure -vvI "${certfirst}" 2>&1 | awk 'BEGIN { cert=0 } /^\* SSL connection/ { cert=1 } /^\*/ { if (cert) print }')" \
    >> /dev/null 2>&1 &
  )
  addtologs "sent mail with subject '${subj}'"
}

#
# VARIABLES:
#

show=$1
does=$2
conf=$3
if [ -z "${conf}" ] || [ "${conf}" == "-" ]; then
  conf="$(dirname "$(realpath "$0")")/$(basename -s .sh "$0").conf"
fi

time=$(date +%s)
cd "$(dirname "$(realpath "$0")")" || execerror
if [ ! -e "${conf}" ]; then
  :
else
  getconfig
fi
if [ -z "${logs}" ]; then
  logs=/dev/null
elif [ ! -e "${logs}" ]; then
  touch "${logs}"
fi

if ! command -v curl &> /dev/null || \
  ! command -v openssl &> /dev/null || \
  ! command -v certbot &> /dev/null || \
  ! command -v /opt/zimbra/bin/zmcontrol &> /dev/null || \
  ! command -v /opt/zimbra/bin/zmcertmgr &> /dev/null || \
  ! command -v /opt/zimbra/libexec/zmqstat &> /dev/null || \
  ! command -v /usr/local/bin/sendmail.py &> /dev/null || \
  ! command -v "${python3}" &> /dev/null; then
  execerror "Not found dependencies"
fi

#
# MAIN:
#

if checkroot; then
  if [ "${does}" = "ssl" ]; then
    expired=$(certcheck "/etc/letsencrypt/live/${certfirst}/cert.pem")
    targets=$(( expired - 2592000 ))
    if [[ "${time}" -le "${targets}" ]]; then
      addtologs "${certfirst} expired $(date -d "1970-01-01 UTC $expired seconds" +"%Y.%m.%d %T")"
      addtologs "${certfirst} certificates renew delayed"
    else
      certrenew && addtologs "${certfirst} certificates renewed"
      startsendmail
    fi
  elif [ "${does}" = "que" ]; then
    result=$(calcqueue)
    addtologs "Zimbra queue has ${result} objects" > /dev/null
    printf "%s\n" "${result}"
    execquite > /dev/null
  elif [ "${does}" = "svc" ]; then
    result=$(isrunning)
    addtologs "Zimbra has ${result} stopped services" > /dev/null
    printf "%s\n" "${result}"
    execquite > /dev/null
  else
    printf "%s\n" "Usage example: $0 qn ssl"
    printf "%s\n" "Usage example: $0 - que"
  fi
  execquite
else
  execerror "Restart this as root!"
fi