#!/bin/sh -e

# Debian Postfix preinst
# LaMont Jones <lamont@debian.org>
# Modified to use debconf by Colin Walters <levanti@verbum.org>

# do we have debconf?
if [ -f /usr/share/debconf/confmodule ]; then
    . /usr/share/debconf/confmodule
    DEBCONF=true
else
    DEBCONF=
fi

dpkg_vers=$(dpkg --status dpkg | sed -n '/Version: /s/^Version: //p')
CONFIG=/etc/postfix/main.cf
MASTER=/etc/postfix/master.cf
POSTDROP=/usr/sbin/postdrop

mydomain_warning() {
    if [ -n "$DEBCONF" ]; then
	db_fset postfix/mydomain_warning seen false
	db_input medium postfix/mydomain_warning || true
	db_go || true
	db_get postfix/mydomain_warning
	if [ "$RET" = "false" ]; then
	    echo "aborting postfix install"
	    exit 1
	fi
    else
	# no debconf, fall back
	cat << EOF
Postfix version 2.3.3-2 and later require changes in main.cf.
Specifically, mydomain must be specified, since hostname(2) is not
an FQDN.
EOF
	echo -n "Shall I make the change? "
	read line
	case ${line} in
	    [nN]*)	echo "aborting postfix install"
			exit 1
			;;
	esac
    fi
}
retry_warning() {
    if [ -n "$DEBCONF" ]; then
	db_fset postfix/retry_upgrade_warning seen false
	db_input medium postfix/retry_upgrade_warning || true
	db_go || true
	db_get postfix/retry_upgrade_warning
	if [ "$RET" = "false" ]; then
	    echo "aborting postfix install"
	    exit 1
	fi
    else
	# no debconf, fall back
	cat << EOF
Postfix version 2.4 requires that the retry service be added to master.cf
EOF
	echo -n "Shall I make the change? "
	read line
	case ${line} in
	    [nN]*)	echo "aborting postfix install"
			exit 1
			;;
	esac
    fi
}
tlsmgr_warning() {
    if [ -n "$DEBCONF" ]; then
	db_fset postfix/tlsmgr_upgrade_warning seen false
	db_input medium postfix/tlsmgr_upgrade_warning || true
	db_go || true
	db_get postfix/tlsmgr_upgrade_warning
	if [ "$RET" = "false" ]; then
	    echo "aborting postfix install"
	    exit 1
	fi
    else
	# no debconf, fall back
	cat << EOF
Postfix version 2.2 has changed the invocation of tlsmgr.
EOF
	echo -n "Shall I make the change? "
	read line
	case ${line} in
	    [nN]*)	echo "aborting postfix install"
			exit 1
			;;
	esac
    fi
}

kernel_version_warning() {
    if [ -n "$DEBCONF" ]; then
	db_fset postfix/kernel_version_warning seen false
	db_input low postfix/kernel_version_warning || true
	db_go || true
	db_get postfix/kernel_version_warning
    else
	cat << EOF
Postfix uses features that are not found in kernels prior to 2.6.  If you
proceeed with the installation, Postfix will not run.
EOF
	RET=false
    fi
    if [ "$RET" = "false" ]; then
	echo "Aborting postfix install"
	exit 1
    fi
}

(umask 022; mkdir -p /var/spool/postfix)

case "$1" in
    install)
	rm -f /var/spool/postfix/restart /var/spool/postfix/reload
	# workaround sendmail not unregistering itself...
	if [ -e /etc/suid.conf ] && [ -x /usr/sbin/suidunregister ]; then
	    if grep -q sendmail /etc/suid.conf; then
		/usr/sbin/suidunregister -s postfix /usr/sbin/sendmail
	    fi
	fi

	if [ -L /etc/postfix/postfix-script ]; then
		rm -f /etc/postfix/postfix-script
	fi

	;;

    upgrade)
	version=$2
	if [ -d /var/spool/postfix ] && [ -f /etc/postfix/main.cf ]; then
	    touch /var/spool/postfix/restart
	fi
	export LANG=C	# for the comparison of mail version...

	if dpkg --compare-versions "`uname -r`" lt 2.6.0 ; then
	    kernel_version_warning
	fi

	if [ -L /etc/postfix/postfix-script ]; then
		rm -f /etc/postfix/postfix-script
	fi

	if grep -q '^tlsmgr[[:space:]]*fifo' $MASTER; then
	  tlsmgr_warning
	fi

	if dpkg --compare-versions $version lt 2.3.5-1; then
	  # droping 10hostname.dpatch forces cleanup.
	  if [ -z "$(postconf -n mydomain 2>/dev/null || true)" ]; then
	    myhost=$(hostname 2>/dev/null)
	    if [ "X${myhost%.*}" = "X${myhost}" ]; then
	      mydomain_warning
	      touch /var/spool/postfix/mydomain-upgrade
	    fi
	  fi
	fi

	if ! grep -q '^retry[[:space:]]' $MASTER; then
	  retry_warning
	fi
	invoke-rc.d --quiet postfix stop || true
	;;

    abort-upgrade)
	;;

    *)
	echo "preinst called with unknown argument \`$1'" >&2
	exit 1
	;;
esac

if [ install = "$1" -o upgrade = "$1" ]; then
    # cleanup after past mistakes.
    rm -f /usr/sbin/postconf.postfix
    dpkg-divert --package postfix-tls --remove \
	 --divert /usr/sbin/postconf.postfix \
		  /usr/sbin/postconf >/dev/null 2>/dev/null
fi