#!/bin/bash -e

fatal() { echo "fatal [$(basename $0)]: $@" 1>&2; exit 1; }
info() { echo "info [$(basename $0)]: $@"; }

usage() {
cat<<EOF
Syntax: $(basename $0) email
Configure security alert emails
EOF
exit 1
}

configure_alias() {
    info $FUNCNAME $@
    user=$1
    email=$2
    cfg=/etc/aliases
    touch $cfg
    grep -q ^${user}: $cfg || (echo "$user:    $email" >> $cfg; return)
    sed -i "s/${user}:.*/${user}:    $email/" $cfg
    newaliases
}

configure_cronapt() {
    info $FUNCNAME $@
    key=$1
    val=$2
    cfg="/etc/cron-apt/config"
    [ -e $cfg ] || return
    grep -q ^${key}= $cfg || (echo "$key=\"$val\"" >> $cfg; return)
    sed -i "s/^${key}=.*/$key=\"$val\"/" $cfg
}

send_enabled_notification() {
    info $FUNCNAME $@
    recipient=$1
    subject="[$(hostname)] system alerts and notifications enabled"
    mail -s "$subject" $recipient <<EOF
This server is configured to send you system alerts and notifications.
For more information, see:
https://www.turnkeylinux.org/security-alerts

--
$(turnkey-version)
EOF
}

enable_security_alerts() {
    info $FUNCNAME $@
    email=$1

    f=/etc/apt/apt.conf.d/01turnkey
    [ -e "$f" ] && turnkey_version=$(sed "s/.*(\(.*\)).*/\1/" $f)
    [ -n "$turnkey_version" ] || turnkey_version=$(turnkey-version)

    script=/etc/cron.hourly/enable_secalerts
    cat>$script<<EOF
#!/bin/bash -e
# created by: $(readlink -f $0)
curl https://hub.turnkeylinux.org/api/server/secalerts/ \\
    -d email="$email" \\
    -d turnkey_version="$turnkey_version" \\
    --silent --fail --output /dev/null || exit 0

rm -f \$0
EOF

    chmod +x $script
    $script
}

if [[ "$#" != "1" ]]; then
    usage
fi

email=$1

configure_alias "root" "$email"
configure_cronapt "MAILON" "output"
configure_cronapt "MAILTO" "root"
send_enabled_notification "root"
enable_security_alerts "$email"