#!/bin/bash

if [ "${EUID}" -ne 0 ]; then
  echo "You must be root to run this installer."
  exit
fi

# check for Debian 12 (bookworm)
os_id=`lsb_release -is`
os_release=`lsb_release -rs`
if [ $os_id != Debian ] || [ $os_release != 12 ]; then
  echo "This installer only runs on Debian 12 (Bookworm), bailing out."
  exit 1
fi

# check if install is already in place
if [ -d "/var/vmail/" ]; then
  echo "vmail-stack is already installed, bailing out."
  exit
fi

# check for existing mail server software installs
if [ -d "/etc/exim4/" ] || [ -d "/etc/dovecot/" ]; then
  echo "WARNING: Exim and/or Dovecot are already installed."
  echo "This installer will overwrite existing configurations."
  echo -e "You have five seconds to execute ctrl-c to cancel this install.\a"
  sleep 5
fi

apt-get update

# install pwgen, used to create random passwords
DEBIAN_FRONTEND=noninteractive apt-get -y install pwgen

# install mariadb (mysql)
if [ ! -d "/etc/mysql/" ]; then

  MARIADBPWORD=`pwgen 12 1`
  DEBIAN_FRONTEND=noninteractive apt-get -y install mariadb-client mariadb-server
  # set unix_socket auth for root
  mysql -e "GRANT ALL ON *.* TO 'root'@'localhost' IDENTIFIED VIA unix_socket WITH GRANT OPTION"
  # create nagios user for monitoring server status only
  mysql -e "CREATE USER 'nagios'@'localhost' IDENTIFIED WITH mysql_native_password AS '';"
  mysqladmin flush-privileges

elif ! systemctl is-active --quiet mysql ; then

  echo "MySQL config dir exists, but MySQL/MariaDB server is not running."
  echo "Check your server config and either make sure MySQL is running"
  echo "or purge MySQL/MariaDB and all related packages (e.g. mysql-common)"
  echo "from the server and then re-run this installer."
  exit 1

fi

# create vmail user & db
mysqladmin create vmail
mysql vmail < vmail.sql
VMAILPASS=`pwgen -1 12`
mysql -e "CREATE USER 'vmail'@'localhost' IDENTIFIED BY '$VMAILPASS';"
mysql -e "GRANT ALL PRIVILEGES ON vmail.* TO 'vmail'@'localhost';"
mysqladmin flush-privileges

# install mail server software
DEBIAN_FRONTEND=noninteractive apt-get -y install exim4-daemon-heavy spf-tools-perl spamassassin srs libclass-dbi-mysql-perl dovecot-core dovecot-imapd dovecot-mysql dovecot-pop3d dovecot-lmtpd mailutils

# configure system users
DEBIAN_FRONTEND=noninteractive apt-get -y install ssl-cert
usermod -a -G ssl-cert Debian-exim
useradd --create-home --home-dir /var/vmail --shell /usr/sbin/nologin --system --user-group vmail

# configure vmail user .my.cnf for db access
install --owner=vmail --group=vmail --mode=640 /dev/null /var/vmail/.my.cnf
echo "[client]" > /var/vmail/.my.cnf
echo "host     = localhost" >> /var/vmail/.my.cnf
echo "user     = vmail" >> /var/vmail/.my.cnf
echo "password = $VMAILPASS" >> /var/vmail/.my.cnf
echo "socket   = /var/run/mysqld/mysqld.sock" >> /var/vmail/.my.cnf
echo "[mysql]" >> /var/vmail/.my.cnf
echo "database = vmail" >> /var/vmail/.my.cnf

# configure vmail dirs
chmod 750 /var/vmail/
if [ ! -d "/etc/ssl/dkim" ]; then
  mkdir /etc/ssl/dkim
fi
chown Debian-exim:ssl-cert /etc/ssl/dkim
chmod 750 /etc/ssl/dkim

# spamassassin config
sed -i "s|userpref|sa_userpref|g" /usr/share/doc/spamassassin/sql/userpref_mysql.sql
sed -i "s|username varchar(100)|username varchar(255)|g" /usr/share/doc/spamassassin/sql/userpref_mysql.sql
sed -i "s|TYPE=MyISAM||g" /usr/share/doc/spamassassin/sql/userpref_mysql.sql
mysql vmail < /usr/share/doc/spamassassin/sql/userpref_mysql.sql
sed -i 's|OPTIONS="--create-prefs --max-children 5 --helper-home-dir"|OPTIONS="-x -q -v -u Debian-exim -m 5"|g' /etc/default/spamd
cp etc/spamassassin/*.cf /etc/spamassassin/
sed -i "s|user_scores_sql_password         password|user_scores_sql_password         $VMAILPASS|g" /etc/spamassassin/sql.cf
chown root:root /etc/spamassassin/local.cf
chmod 644 /etc/spamassassin/local.cf
chown Debian-exim:mail /etc/spamassassin/sql.cf
chmod 640 /etc/spamassassin/sql.cf

# create local systemd dir, used by srsd & vmail-cron
if [[ ! -d /usr/local/lib/systemd/system ]]; then
  mkdir -p /usr/local/lib/systemd/system
fi

# exim config
fqdn=`hostname -f`
maildomain=`hostname -d`
sed -i 's/nocreate/create 640 Debian-exim adm/g' /etc/logrotate.d/exim4-base
sed -i 's/size 10M/daily/g' /etc/logrotate.d/exim4-paniclog
install --owner=Debian-exim --group=Debian-exim --mode=640 /dev/null /etc/exim4/relay_domains
cp etc/exim4/* /etc/exim4/
chmod 640 /etc/exim4/exim4.conf
chown Debian-exim:Debian-exim /etc/exim4/autowhitelist.filter
chmod 640 /etc/exim4/autowhitelist.filter
chown Debian-exim:Debian-exim /etc/exim4/return-resender.sh
chmod 640 /etc/exim4/return-resender.sh
chown Debian-exim:Debian-exim /etc/exim4/skip_greylisting_hosts
chmod 640 /etc/exim4/skip_greylisting_hosts
sed -i "s|example.com|$maildomain|g" /etc/exim4/skip_greylisting_hosts
sed -i "s|password|$VMAILPASS|g" /etc/exim4/exim_local.conf
sed -i "s|fqdn.example.com|$fqdn|g" /etc/exim4/exim_local.conf
sed -i "s|example.com|$maildomain|g" /etc/exim4/exim_local.conf
touch /etc/exim4/srsd.secret
chmod 640 /etc/exim4/srsd.secret
chown Debian-exim:Debian-exim /etc/exim4/srsd.secret
pwgen -N 1 64 > /etc/exim4/srsd.secret
sed -i "s|^QUEUERUNNER.*|QUEUERUNNER='separate'|g" /etc/default/exim4
sed -i "s|^QUEUEINTERVAL.*|QUEUEINTERVAL='15m'|g" /etc/default/exim4
install --owner=Debian-exim --group=adm --mode=640 /dev/null /var/log/exim4/rejectlog

# srsd
# bug fixes for libmail-srs-perl. still needed as of v0.31-9 on Debian 12
sed -i 's|/tmp/srsd|/run/srsd/srsd.sock|' /usr/share/perl5/Mail/SRS/Daemon.pm
sed -i '/Until we decide that forward/,+3d' /usr/share/perl5/Mail/SRS/Daemon.pm
cp systemd/srsd.service /usr/local/lib/systemd/system/srsd.service
chmod 644 /usr/local/lib/systemd/system/srsd.service
systemctl daemon-reload
systemctl enable srsd
systemctl start srsd

# dovecot config
mkdir /etc/dovecot/sites.d
cp -a etc/dovecot/* /etc/dovecot/
chgrp dovecot /etc/dovecot/dovecot-sql.conf.ext
chmod 640 /etc/dovecot/dovecot-sql.conf.ext
sed -i "s|password=password|password=$VMAILPASS|g" /etc/dovecot/dovecot-sql.conf.ext
if ! [ -d "/usr/local/libexec" ]; then
  mkdir /usr/local/libexec
fi
cp libexec/vmail-quota-warning.sh /usr/local/libexec/
chmod 750 /usr/local/libexec/vmail-quota-warning.sh
chown dovecot:mail /usr/local/libexec/vmail-quota-warning.sh

# restart services
systemctl enable spamd
systemctl restart spamd
systemctl restart exim4
systemctl restart dovecot

chmod 755 bin/*
cp bin/* /usr/local/bin/

# install & enable vmail systemd cron
cp sbin/vmail-cron.sh /usr/local/sbin/
chmod 755 /usr/local/sbin/vmail-cron.sh
cp systemd/vmail-cron.* /usr/local/lib/systemd/system/
chmod 644 /usr/local/lib/systemd/system/vmail-cron.*
systemctl enable vmail-cron.timer
systemctl start vmail-cron.timer

# enable email ports in firewalld
if [[ -d /etc/firewalld/ ]]; then
  firewall-cmd --permanent --zone=public --add-service=smtp
  firewall-cmd --permanent --zone=public --add-service=smtp-submission
  firewall-cmd --permanent --zone=public --add-service=smtps
  firewall-cmd --permanent --zone=public --add-service=imap
  firewall-cmd --permanent --zone=public --add-service=imaps
  firewall-cmd --permanent --zone=public --add-service=pop3
  firewall-cmd --permanent --zone=public --add-service=pop3s
  firewall-cmd --zone=public --add-service=smtp
  firewall-cmd --zone=public --add-service=smtp-submission
  firewall-cmd --zone=public --add-service=smtps
  firewall-cmd --zone=public --add-service=imap
  firewall-cmd --zone=public --add-service=imaps
  firewall-cmd --zone=public --add-service=pop3
  firewall-cmd --zone=public --add-service=pop3s
else
  echo
  echo "firewalld not installed, not opening email ports in firewall."
fi

# fail2ban
if [[ -d /etc/fail2ban/ ]]; then
  chmod 644 etc/fail2ban/*/*.conf
  cp -a etc/fail2ban/* /etc/fail2ban/
else
  echo
  echo "fail2ban not installed, skipping fail2ban email configs."
fi

sed -i '/^root/d' /etc/aliases
echo "webmaster@$maildomain" > /root/.forward
echo
echo "System emails are all configured to alias to root@$fqdn,"
echo "which in turn forwards to webmaster@$maildomain."
echo "Adjust /etc/aliases & /root/.forward as desired."
echo
echo "To install the Mailman3 mailing list software run:"
echo "install-mm3.sh"