#!/bin/bash
# shellcheck disable=SC1091
[ -r /var/lib/from_repos/scripts/shared_functions.sh ] && . /var/lib/from_repos/scripts/shared_functions.sh
function usage() {
    echo "Usage:"
    echo "$(basename "${0}") -p|--porpouse <porpouse> [-o|--domain <DOMAIN>] [-l|--length <ALIAS_LENGTH>] [-e|--destination <DESTINATION>]"
    echo ""
    echo "  -d|--debug                     Show more debug information."
    echo "  -p|--porpouse <PORPOUSE>       Porpouse of this forwarding that will help you remember why you created it."
    echo "  -o|--domain <DOMAIN>           Domain name for the alias. From the list:"
    while read -r DOMAIN
    do
        echo "    # ${DOMAIN}"
    done <<< "$(echo 'select domain FROM mail.domains' | mysql mail|grep -v '^domain$')"
    echo "  -l|--length <ALIAS_LENGTH>     Length of pseudo-random character of the alias."
    echo "  -e|--destination <DESTINATION> Destination of the forwarding."
    echo "  -a|--alias <ALIAS>             Use a defined alias."
}
domain="susurrando.com"
alias_length=6
destination="ad@susurrando.com"
alias=""
while [ $# -gt 0 ]
do
case "${1}" in
    "-h"|"-?"|"--help")
    shift
    usage
    exit 0
    ;;
    "-d"|"--debug")
    shift
    export DEBUG=true
    ;;
    "-o"|"--domain")
    shift
    domain="${1}"
    existing=$(echo "select domain FROM mail.domains WHERE domain = '${domain}';" | mysql mail | grep -v '^domain$')
    if [ -z "${existing}" ]; then
        message "The domain '${domain}' doesn't exist in the database. Add it first." p
        echo "Current list of domains:"
        while read -r DOMAIN
        do
            echo "    # ${DOMAIN}"
        done <<< "$(echo 'select domain FROM mail.domains' | mysql mail|grep -v '^domain$')"
        exit 4
    fi
    shift
    ;;
    "-l"|"--length")
    shift
    alias_length="${1}"
    shift
    ;;
    "-e"|"--destination")
    shift
    destination="${1}"
    shift
    ;;
    "-p"|"--porpouse")
    shift
    porpouse="${1}"
    shift
    ;;
    "-a"|"--alias")
    shift
    alias="${1}"
    shift
    ;;
    *)
    message "Unknown parameter '$1'" p
    shift
    ;;
esac
done

if [ -z "${porpouse}" ]; then
    message "You have to provide a porpouse." p
    usage
    exit 1
fi
existing=$(echo "SELECT * FROM mail.forwardings where porpouse = '${porpouse}';" | mysql mail)
if [ -n "${existing}" ]; then
    message "There is already an alias for that porpouse:" p
    message "${existing}" p
    exit 2
fi

if [ -n "${alias}" ]; then
    existing=$(echo "SELECT source FROM mail.forwardings where source = '${alias}';" |mysql mail | grep -v '^source$')
    if [ -n "${existing}" ]; then
        message "Alias already exist in the database:" p
        message "'${existing}'" p
        exit 3
    fi
fi

while [ "${alias}" == "" ]
do
    random_string=$(LC_ALL=C tr -dc A-Za-z0-9 </dev/urandom | head -c "${alias_length}")
    existing=$(echo "SELECT source FROM mail.forwardings where source = '${random_string}@${domain}';" |mysql mail |grep -v '^source$')
    if [ -z "${existing}" ]; then
        alias="${random_string}@${domain}"
        message "Generated alias: '${alias}'"
    else
        message "Generated alias '${random_string}@${domain}' exists in the database."
        message "'${existing}'"
    fi
done
echo "INSERT INTO mail.forwardings (source, destination, porpouse) VALUES ('${alias}','${destination}','${porpouse}');"| mysql mail
message "Inserted forwarding from '${alias}' to '${destination}' for the porpouse of '${porpouse}'." p