package

#!/bin/bash

# Builds a Debian package
# Requirements: bash, findutils, gzip

# Enable failure on command or piped command failures
set -o errexit
set -o pipefail

function die() {
    echo $* >&2
    exit 1
}

# The name of the package to build
PKG=exim4-disposable-aliases

SCRIPT=$(readlink -f ${BASH_SOURCE[0]})
HERE=$(dirname "$SCRIPT")
EXIM=${EXIM:-/etc/exim4}
EXIMUSER=${EXIMUSER:-Debian-exim}
EXIMGROUP=${EXIMGROUP:-Debian-exim}
LOGGROUP=${LOGGROUP:-adm}
WRITABLE=${WRITABLE:-0750}
READABLE=${READABLE:-0644}

{ # Parse and validate the command options
    while getopts ":b:d" option; do
        case $option in
	    # -b defines a staging directory in which the files are installed.
	    # This directory must exist.
            b) BASEDIR="$OPTARG" ;;
	    d) DEBUG=1 ;;
	    *) 
		echo "Invalid option: $OPTARG"
		exit 1
		;;
	esac
    done
    shift $(( $OPTIND - 1 ))
}

# Sanity checks
[[ -n "$BASEDIR" ]] || die "Base directory set to a non-directory: $BASEDIR"
[[ "$READABLE" == 0+([0-9]) ]] || die "READABLE must be a valid numeric file permission mode"
[[ "$WRITABLE" == 0+([0-9]) ]] || die "WRITABLE must be a valid numeric file permission mode"

# Enable debugging?
if [[ -n "$DEBUG" ]]; then
    printenv
    set -vx
fi

function myinstall() {
    install -m $1 "$2" "$3"
}

# Temporary build directory
BUILDDIR="$BASEDIR/build"

# The sqlite3 binary on the target system
SQLITE=/usr/bin/sqlite3

export DISP_ALIASES_DB=/var/spool/exim4/db/disposable-aliases.db
export DISP_ALIASES_FILTER="$EXIM/conf.d/disposable-aliases-filter"
export DISP_ALIASES_LOGDIR=/var/log/exim4/disposable-aliases
export DISP_ALIASES_LOGROTATE_CONF="/etc/logrotate.d/$PKG"
export DISP_ALIASES_DATA_ACL="$EXIM/conf.d/disposable-aliases-data-acl"
export DISP_ALIASES_MACROS="$EXIM/conf.d/main/00_disposable-aliases-macros"
export DISP_ALIASES_ROUTER="$EXIM/conf.d/router/450_disposable_aliases"

{ # Install package files
    # Remove and re-create the build directory
    rm -rf "$BUILDDIR"
    mkdir "$BUILDDIR"
    
    if [[ -n "$BUILDDIR" ]]; then
	# Ensure the target directories exist if we're not installing to the root filesystem
	mkdir -pv "$BUILDDIR${DISP_ALIASES_DB%/*}"
	mkdir -pv "$BUILDDIR${DISP_ALIASES_FILTER%/*}"
	mkdir -pv "$BUILDDIR${DISP_ALIASES_MACROS%/*}"
	mkdir -pv "$BUILDDIR${DISP_ALIASES_ROUTER%/*}"
    fi    
    
    mkdir -vp "$BUILDDIR$DISP_ALIASES_LOGDIR"
    
    chmod $WRITABLE "$BUILDDIR$DISP_ALIASES_LOGDIR"
    
    cat >"$BUILDDIR$DISP_ALIASES_MACROS" <<EOF
# This needs to be included before the routers

DISP_ALIASES_DB = $DISP_ALIASES_DB
DISP_ALIASES_FILTER = $DISP_ALIASES_FILTER
DISP_ALIASES_LOGDIR = $DISP_ALIASES_LOGDIR
CHECK_DATA_LOCAL_ACL_FILE = $DISP_ALIASES_DATA_ACL

# For now set the sqlite file globally - Exim v4.90 does not yet support per-lookup file specs.
# Will find a workaround for this later.
sqlite_dbfile = DISP_ALIASES_DB

EOF

    mkdir -p "$BUILDDIR${DISP_ALIASES_LOGROTATE_CONF%/*}"
    cat >"$BUILDDIR$DISP_ALIASES_LOGROTATE_CONF" <<EOF
$DISP_ALIASES_LOGDIR/*.log {
    rotate 12
    weekly
    compress
    missingok
}
EOF

    myinstall $READABLE "$HERE/router" "$BUILDDIR$DISP_ALIASES_ROUTER"

    ./expand-macros <"$HERE/filter" >"$BASEDIR/filter.tmp"
    myinstall $READABLE "$BASEDIR/filter.tmp" "$BUILDDIR/$DISP_ALIASES_FILTER"
    rm "$BASEDIR/filter.tmp"

    myinstall $READABLE "$HERE/data-acl" "$BUILDDIR/$DISP_ALIASES_DATA_ACL"

    DOCS="$BUILDDIR/usr/share/doc/$PKG"
    mkdir -p "$DOCS"    

    CHANGELOG="$DOCS/changelog.gz"
    gzip -n --best <"$HERE/ChangeLog" >"$CHANGELOG"

    cp "$HERE/COPYRIGHT" "$DOCS/copyright"

    cp "$HERE/README.md" "$DOCS"

    cp "$HERE/schema.sql" "$DOCS"

    # Ensure there aren't any crazy modes in $BUILDDIR
    find $BUILDDIR -type f -exec chmod 0644 \{} \;
    find $BUILDDIR -type d -exec chmod 0755 \{} \;
}

{
    # Create debian package files
    mkdir "$BUILDDIR/DEBIAN"
    cat >"$BUILDDIR/DEBIAN/control" <<EOF
Package: exim4-disposable-aliases
Version: $(<./version)
Section: mail
Priority: optional
Architecture: all
Maintainer: Nick Stokoe <exim4-disposable-aliases.wu-lee@noodlefactory.co.uk>
Homepage: https://github.com/wu-lee/exim4-disposable-aliases
Build-Depends: debhelper (>=9), perl
Depends: exim4-daemon-heavy (>= 4.94), sqlite3
Description: Disposable email address aliases for Exim4
 Inspired by Spamgourmet, this project consists primarily of an Exim
 router configuration with an associated Exim filter script, which
 performs the logic by means of a lookup into a SQLite database file.
 Dependencies are intentionally minimal.
EOF

    (cd $BUILDDIR; find etc/ -type f -printf "/%p\n" >"DEBIAN/conffiles")

    cat >$BUILDDIR/DEBIAN/postinst <<EOF
#!/bin/sh
set -e
if [ ! -e "$DISP_ALIASES_DB" ]; then
    # Initialise the database
    "$SQLITE" "$DISP_ALIASES_DB" <"/usr/share/doc/$PKG/schema.sql"
    chmod $WRITABLE "$DISP_ALIASES_DB"
else
    # Upgrade steps would go here. None currently as there is only one schema!
    echo
fi

# Allow exim access to the database and log directoy
chown "$EXIMUSER:$EXIMGROUP" "$DISP_ALIASES_DB"
chown "$EXIMUSER:$LOGGROUP" "$DISP_ALIASES_LOGDIR"

# Restart exim daemon, if it is running. This will rebuild the config too
[ -x /etc/init.d/exim4 ] && /etc/init.d/exim4 try-restart
EOF
    
    cat >$BUILDDIR/DEBIAN/postrm <<EOF
#!/bin/sh
set -e
if [ "\$1" = "purge" ]; then
    rm -f "$DISP_ALIASES_DB"
    rm -rf "$DISP_ALIASES_LOGDIR"
fi

# Restart exim daemon, if it is running. This will rebuild the config too
[ -x /etc/init.d/exim4 ] && /etc/init.d/exim4 try-restart
EOF

    chmod +x "$BUILDDIR/DEBIAN/"{postrm,postinst}
}

# Build the archive
dpkg-deb --root-owner-group --build "$BUILDDIR" "$BASEDIR/$PKG.deb"

# Check the archive
lintian "$BASEDIR/$PKG.deb"